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OKANO KentaroGraduate School of Engineering / Department of Chemical Science and EngineeringProfessor
Research activity information
■ Award- Dec. 2016 The Society of Synthetic Organic Chemistry, Incentive Award in Synthetic Organic Chemistry, Japan, 新規合成方法論の開発を基盤とする含窒素高次縮環天然物の全合成Japan society
- 2014 Georg Thieme Verlag KG, Thieme Chemistry Journal Award 2015, Awardees are loosely defined as promising young professors at the beginning of their career.Publisher
- 2013 天然物化学談話会, 平成25年度 天然物化学談話会 奨励賞, 特異な含窒素縮合環を有する天然有機化合物の合成研究Japan society
- 2012 日本薬学会, 平成24年度 日本薬学会東北支部 奨励賞, 芳香族炭素-窒素結合形成法の開発を鍵とする含窒素芳香族天然物の合成研究Japan society
- 2011 井上科学振興財団, 第27回 井上研究奨励賞, Enantioselective Total Synthesis of (+)-Yatakemycin Based on CuI-Mediated Aryl AminationJapan society
- 2011 Inoue Research Award for Young Scientists
- 2009 有機合成化学協会, 2009年度 有機合成化学協会 旭化成ファーマ研究企画賞, 配位子による触媒 機能の動的変化を基盤とするワンポット多成分連続反応の開発Japan society
- The C–H arylation of 2-quinolinecarboxyamide bearing C–Br bond at the N-aryl moiety is carried out with a palladium catalyst. The reaction proceeds at the C–H bond on the pyridine ring adjacent to the amide group in the presence of 10 mol% Pd(OAc)2 at 110 °C to afford the cyclized product in 42% yield. The yield is improved to 94% when the reaction is performed with PPh3 as a ligand of palladium. The reaction is examined with amides derived from unsubstituted picoline, 6-methyl-picoline, and 2,6-pyridinedicarboxylic acid in a similar manner to afford the cyclized product in 70%, 77%, 87%, respectively. The related reaction is also carried out with amides of non-pyridine derivatives terephthal- and benz- amides to afford multiply-fused heterocyclic compounds in 81% and 89% yields, respectively.Beilstein Institut, Nov. 2024
- The reaction of phenanthroline diamide bearing a bromoaryl moiety on the amide substituent in the presence of palladium catalyst proceeded efficiently to afford multiply-fused phenanthroline derivatives through intramolecular C–H arylation. The obtained diamide derivatives was found to extract lanthanide remarkably highly efficiently with distribution ratio (D: up to ca. 500) and it was also found show the metal-selective extraction (separation factor SF = up to 4.4).American Chemical Society (ACS), Sep. 2024
- Sep. 2024, Journal of Organic Chemistry, 89(18) (18), 13472 - 13484Scientific journal
- Jul. 2024, ChemCatChem, 16(14) (14)Scientific journal
- Jun. 2024, Journal of Organic Chemistry, 89(11) (11), 8185 - 8191Scientific journal
- Wiley, Apr. 2024, Chemistry – A European Journal, 30(35) (35)Scientific journal
- Mar. 2024, Organic & biomolecular chemistry, 22(13) (13), 2574 - 2579, English, International magazineScientific journal
- Mar. 2024, Polymer Chemistry, 15(16) (16), 1635 - 1641Scientific journal
- Feb. 2024, Chemistry (Weinheim an der Bergstrasse, Germany), 30(23) (23), e202400104, English, International magazineScientific journal
- 2024, European Journal of Organic Chemistry, 27(20) (20)Scientific journal
- Dec. 2023, ChemRxiv, English
- Nov. 2023, ChemRxiv, English
- Catalytic potassium hexamethyldisilazide (KHMDS) accelerates a bromine–metal exchange rather than potassium tert-butoxide (KOtBu), which is stoichiometrically used for the Lochmann–Schlosser base, a combination of nBuLi and KOtBu. Loading of 1.0–10 mol% of KHMDS drastically facilitated successive bromine–metal exchanges consisting of a halogen dance reaction within 1 min to introduce various electrophiles on bromopyridine, imidazole, thiophene, furan, and benzene derivatives with the bromo group translocated from the original position. A dual catalytic cycle is proposed to explain the ultra-fast bromine transfer showing the significant potential to realize new catalytic reactions of aryllithium species using KHMDS.American Chemical Society (ACS), Nov. 2023
- American Chemical Society (ACS), Aug. 2023, Organic Letters, 25(36) (36), 6693 - 6698[Refereed]Scientific journal
- Jul. 2023, Molecular Systems Design and Engineering, 8(10) (10), 1252 - 1256[Refereed]Scientific journal
- Jul. 2023, SYNLETT, English[Refereed][Invited]Scientific journal
- A method for the regioselective functionalization of haloarenes through deprotonative lithiation is disclosed. The generated haloaryllithiums were trapped in a batch reactor with a zinc chloride diamine complex to provide organozinc species without aryne formation, which reacted with electrophiles to afford the corresponding products in 38-98% yields. This method was applied to the five-step total synthesis of carbazomycin A on a gram scale in 33% overall yield.May 2023, Organic letters, 25(17) (17), 3013 - 3017, English, International magazine[Refereed]Scientific journal
- A formal synthesis of dictyodendrin B is described. Regiocontrolled functionalization of the α,β-dibromopyrrole derivative provided the fully substituted pyrrole bearing an indole moiety. Subsequent reductive cyclization using a combination of sodium dispersion and triethylsilyl chloride enabled the formation of the benzene ring in the characteristic tetracyclic pyrrolo[2,3-c]carbazole skeleton, while the ethyl ester remained untouched. Further chemical transformation of the ester moiety and functional group manipulation completed the formal synthesis of dictyodendrin B.Apr. 2023, Organic letters, 25(15) (15), 2669 - 2673, English, International magazine[Refereed]Scientific journal
- Mar. 2023, ACS Catalysis[Refereed]Scientific journal
- Feb. 2023, Synlett, 34(20) (20), 2401 - 2404[Refereed]Scientific journal
- The Chemical Society of Japan, Feb. 2023, Chemistry Letters, 52(2) (2), 116 - 119, English[Refereed]Scientific journal
- Jan. 2023, CHEMICAL COMMUNICATIONS, 59(8) (8), 1046 - 1049, English[Refereed]Scientific journal
- Thiophene–thiophene block copolymer composed of hydrophilic and hydrophobic side chain functionalities was designed and synthesized. Deprotonative metalation nickel-catalyzed polymerization protocol successfully afforded the block copolymer, which side chains are derived...Royal Society of Chemistry (RSC), 2023, Journal of Materials Chemistry C[Refereed]Scientific journal
- Wiley, Aug. 2022, Asian Journal of Organic Chemistry, 11(8) (8)[Refereed]Scientific journal
- The Chemical Society of Japan, Jun. 2022, Bulletin of the Chemical Society of Japan, 95(6) (6), 882 - 888[Refereed]Scientific journal
- Abstract A total synthesis of lamellarins U and A3 is described. The synthesis features the interruption of a halogen dance reaction of a metalated α,β-dibromopyrrole. The pyrrolylmagnesium reagent, generated by deprotonative metalation by using (TMP)MgCl·LiCl (TMP = 2,2,6,6-tetramethylpiperidide) as the base, was transmetalated to the corresponding organozinc species without causing the halogen dance reaction, which underwent a Negishi coupling to incorporate an aryl group onto the pyrrole ring. The arylated α,β-dibromopyrrole was then converted into lamellarins U and A3 through an α-selective halogen–magnesium exchange followed by carboxylation and subsequent palladium-mediated cyclization. The late-stage introduction of another aryl group was performed using a Kosugi–Migita–Stille coupling to provide lamellarins U and A3.Georg Thieme Verlag KG, Jun. 2022, Synthesis, 54(11) (11), 2647 - 2660[Refereed]Scientific journal
- Nov. 2021, Organometallics, 40(21) (21), 3506 - 3510[Refereed]Scientific journal
- Corresponding, Oct. 2021, JOURNAL OF ORGANIC CHEMISTRY, 86(19) (19), 13388 - 13401, English[Refereed]Scientific journal
- Sep. 2021, Synthesis (Germany), 53(17) (17), 3081 - 3084[Refereed]Scientific journal
- Recent developments in flow microreactor technology have allowed the use of transient organolithium compounds that cannot be realized in a batch reactor. However, trapping the transient aryllithiums in a "halogen dance" is still challenging. Herein is reported the trapping of such short-lived azolyllithiums in a batch reactor by developing a finely tuned in situ zincation using zinc halide diamine complexes. The reaction rate is controlled by the appropriate choice of diamine ligand. The reaction is operationally simple and can be performed at 0 °C with high reproducibility on a multigram scale. This method was applicable to a wide range of brominated azoles allowing deprotonative functionalization, which was used for the concise divergent syntheses of both constitutional isomers of biologically active azoles.Corresponding, Jul. 2021, Chemistry (Weinheim an der Bergstrasse, Germany), 27(40) (40), 10267 - 10273, English, International magazine[Refereed]Scientific journal
- Corresponding, Jul. 2021, Chemistry (Weinheim an der Bergstrasse, Germany), 27(40) (40), 10214 - 10214, English, International magazine[Refereed]
- Jun. 2021, European Journal of Organic Chemistry, 2021(24) (24), 3465 - 3471[Refereed]Scientific journal
- 2021, Organic Syntheses, 98, 509 - 530, English[Refereed]Scientific journal
- Corresponding, 2021, Organic Syntheses, 98, 407 - 429[Refereed]Scientific journal
- 2021, Heterocycles, 103(1) (1)[Refereed]Scientific journal
- Corresponding, Georg Thieme Verlag KG, Dec. 2020, Synlett, 31(19) (19), 1913 - 1918
Abstract Selective trapping of (4,5-dibromo-2-thienyl)lithium, known to undergo halogen dance, was achieved in a flow microreactor. This transient thienyllithium, generated by mixing 2,3-dibromothiophene and lithium diisopropylamide at –78 °C for 1.6 seconds, reacted with benzaldehyde. The reaction system is also applicable to other carbonyl compounds to afford the corresponding adducts in good yields. Moreover, the established conditions permit the conversion of 2,5-dibromothiophene into a mixture of the two constitutional isomers. The contrasting results are discussed on the basis of the reaction pathway.[Refereed][Invited]Scientific journal - Oct. 2020, JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN, 78(10) (10), 930 - 942, JapaneseSynthesis of Multiply Substituted Heteroarenes Using Halogen Dance[Refereed]
- Corresponding, Jul. 2020, JOURNAL OF ORGANIC CHEMISTRY, 85(13) (13), 8603 - 8617, English[Refereed]Scientific journal
- May 2020, TETRAHEDRON, 76(22) (22), EnglishScientific journal
- Feb. 2020, Macromolecules, English[Refereed]Scientific journal
- Corresponding, 2020, Synlett, 31(2) (2), 189 - 193, English[Refereed]Scientific journal
- 2020, Heterocycles, 101(2) (2), 461 - 470, English[Refereed][Invited]Scientific journal
- Differently substituted thiophene−thiophene alternating copolymer was formally synthesized employing a halobithiophene as a monomer. Nickel-catalyzed polymerization of bithiophene, which substituent at the 3-position involves alkyl, fluoroalkyl, or oligosiloxane containing alkyl group, afforded the corresponding copolymer in good to excellent yield. The solubility test to organic solvents was performed to reveal several copolymers show a superior solubility. X-ray diffraction analysis of the thin film of the alternating copolymer composed of methyl and branched oligosiloxane substituents was also performed and found that the film suggested formation of dual-layered structure.Beilstein Institut, Dec. 2019, Beilstein journal of organic chemistry, 16, 317 - 324, English, International magazine[Refereed]Scientific journal
- Aug. 2019, Heterocycles, 99(1) (1), 294 - 300, English[Refereed]Scientific journal
- Wiley, Jul. 2019, Angewandte Chemie, 131(28) (28), 9647 - 9650Scientific journal
- Jul. 2019, Angewante Chemie International Edition, 58(28) (28), 9547 - 9550, English, International magazine[Refereed]Scientific journal
- Jun. 2019, Chemistry Letters, 48(6) (6), 611 - 614, English[Refereed]Scientific journal
- 2019, Heterocycles, 99, 310 - 323, English[Refereed]Scientific journal
- 2019, Organic Letters, 21, English[Refereed]Scientific journal
- 2019, Synthesis (Germany), 51(7) (7), 1561 - 1564[Refereed]Scientific journal
- 2019, Heterocycles, 98(1) (1), 63 - 77[Refereed]Scientific journal
- 2019, Heterocycles, 99(2) (2), 1444 - 1451[Refereed]Scientific journal
- Dec. 2018, Journal of Organic Chemistry, 83(23) (23), 14797–14801 - 14801, English[Refereed]Scientific journal
- Nature Publishing Group, Dec. 2018, Scientific Reports, 8(1) (1), English[Refereed]Scientific journal
- Nov. 2018, JOURNAL OF ORGANIC CHEMISTRY, 83(22) (22), 14126 - 14137, English[Refereed]Scientific journal
- Oct. 2018, ACS OMEGA, 3(10) (10), 12703 - 12706, English[Refereed]Scientific journal
- Aug. 2018, SYNLETT, 29(13) (13), 1786 - 1790[Refereed]
- Jul. 2018, Journal of Polymer Science, Part A: Polymer Chemistry, 56(14) (14), 1516 - 1519, English[Refereed]Scientific journal
- Jul. 2018, EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, 2018(25) (25), 3343 - 3347, English[Refereed]Scientific journal
- Jul. 2018, ASIAN JOURNAL OF ORGANIC CHEMISTRY, 7(7) (7), 1298 - 1301[Refereed]Scientific journal
- May 2018, Angewandte Chemie - International Edition, 57(19) (19), 5413 - 5417, English[Refereed]Scientific journal
- American Chemical Society, Mar. 2018, Organic Letters, 20(6) (6), 1688 - 1691, English[Refereed]Scientific journal
- Georg Thieme Verlag, Mar. 2018, Synlett, 29(4) (4), 513 - 518, English[Refereed]Scientific journal
- American Chemical Society, Feb. 2018, Organic Letters, 20(4) (4), 958 - 961, English[Refereed]Scientific journal
- 2018, Heterocycles, 97(1) (1), 580 - 590, English[Refereed]Scientific journal
- Jun. 2017, SYNLETT, 28(9) (9), 1106 - 1110, English[Refereed]Scientific journal
- May 2017, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 90(5) (5), 565 - 567, English[Refereed]Scientific journal
- Apr. 2017, CHEMISTRY LETTERS, 46(4) (4), 453 - 455, English[Refereed]Scientific journal
- Mar. 2017, SYNTHESIS-STUTTGART, 49(6) (6), 1285 - 1294, English[Refereed]Scientific journal
- Feb. 2017, CHEMICAL COMMUNICATIONS, 53(17) (17), 2614 - 2617, English[Refereed]Scientific journal
- Chemical Society of Japan, 2017, Chemistry Letters, 46(10) (10), 1535 - 1538, English[Refereed]Scientific journal
- Jan. 2017, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 56(4) (4), 1087 - 1091, English[Refereed]Scientific journal
- Jan. 2017, JOURNAL OF ORGANIC CHEMISTRY, 82(1) (1), 353 - 371, English[Refereed]Scientific journal
- Jan. 2017, HETEROCYCLES, 95(1) (1), 268 - 276, English[Refereed]Scientific journal
- Nov. 2016, CHEMISTRY-A EUROPEAN JOURNAL, 22(46) (46), 16450 - 16454, English[Refereed]Scientific journal
- Apr. 2016, HETEROCYCLES, 93(1) (1), 140 - 149, English[Refereed]Scientific journal
- Mar. 2016, SYNLETT, 27(4) (4), 621 - 625, English[Refereed]Scientific journal
- Wiley Blackwell, 2016, Organic Syntheses, 93, 63 - 74, English[Refereed]Scientific journal
- Jan. 2016, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 55(1) (1), 283 - 287, English[Refereed]Scientific journal
- 2016, Org. Synth., 93, 1 - 13, EnglishDIBALH-Mediated Reductive Ring-Expansion Reaction of Cyclic Ketoxime[Refereed]Scientific journal
- Jun. 2015, TETRAHEDRON, 71(23) (23), 3833 - 3837, English[Refereed]Scientific journal
- 2015, CHEMICAL COMMUNICATIONS, 51(6) (6), 1070 - 1073, English[Refereed]Scientific journal
- Jan. 2015, HETEROCYCLES, 90(2) (2), 1299 - 1308, English[Refereed]Scientific journal
- Nov. 2014, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 53(48) (48), 13215 - 13219, English[Refereed]Scientific journal
- Oct. 2014, TETRAHEDRON, 70(43) (43), 8129 - 8141, English[Refereed]Scientific journal
- Oct. 2014, SYNLETT, 25(17) (17), 2503 - 2507, English[Refereed]Scientific journal
- Apr. 2014, CHEMICAL & PHARMACEUTICAL BULLETIN, 62(4) (4), 354 - 363, English[Refereed]Scientific journal
- Jan. 2014, HETEROCYCLES, 88(2) (2), 1433 - 1444, English[Refereed]Scientific journal
- Dec. 2013, Tetrahedron, 69(51) (51), 10946 - 10954, English[Refereed]Scientific journal
- Oct. 2013, SYNLETT, 24(16) (16), 2143 - 2147, English[Refereed]Scientific journal
- Jul. 2013, CHEMISTRY-A EUROPEAN JOURNAL, 19(28) (28), 9325 - 9334, English[Refereed]Scientific journal
- Apr. 2013, ORGANIC LETTERS, 15(8) (8), 1946 - 1949, English[Refereed]Scientific journal
- Apr. 2013, SYNLETT, 24(7) (7), 813 - 816, EnglishScientific journal
- Nov. 2012, TETRAHEDRON, 68(46) (46), 9376 - 9383, EnglishScientific journal
- Jun. 2012, MOLECULES, 17(6) (6), 7348 - 7355, EnglishScientific journal
- May 2012, ORGANIC LETTERS, 14(9) (9), 2320 - 2322, English[Refereed]Scientific journal
- 2012, RSC ADVANCES, 2(12) (12), 5147 - 5149, English[Refereed]Scientific journal
- 2012, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 51(52) (52), 13062 - 13065, English[Refereed]Scientific journal
- Jan. 2012, HETEROCYCLES, 84(2) (2), 1325 - 1334, EnglishScientific journal
- Dictyodendrins (1-5) were isolated in 2003 by Fusetani and Matsunaga from the marine sponge Dictyodendrilla verongiformis. These compounds have found to be the first marine alkaloids which possess inhibitory activity against telomerase (100% inhibition at a concentration of 50 μg/mL). They have attracted considerable attention as synthetic targets not only due to their important biological activity, but also to the unique structure consisting of the highly substituted pyrrolo[2,3-c]carbazole core. Herein, we describe an efficient total synthesis of all the member of dictyodendrins 1-5 featuring a newly developed benzyne-mediated indoline formation-functionalization sequence using magnesium bisamide. From our unsuccessful initial approaches, we learned that regioselective introduction of the substituent at the 7-position after the construction of the indoline skeleton was a difficult task due to its sterically congested environment. At this juncture, we decided to develop a straightforward and regiochemically secured methodology based on benzyne chemistry. Among a variety of bases tested, Mg(TMP)_2-2LiBr was found to be superior for smooth indoline formation and subsequent coupling reaction to give the desired product 19 in excellent yield. The double functionalization methodology was also applied to synthesis of 7-substituted indolines. Having successfully constructed the desired indoline bearing p-anisyl group at 7-position by the efficient benzyne-mediated cyclization cross coupling sequence, we then converted it to pivotal indole 20 by removal of the Boc group, DDQ oxidation to indole, and attachment of p-anisylethyl group on the nitrogen. The installation of subunits on the indole 2-position for the synthesis of dictyodendrin A (1), B (2), and E (5) was successfully carried out. Construction of the tetracyclic core skeleton followed by protecting group manipulation yielded dictyodendrin A (1), B (2), and E (5). By application of the synthetic route, we also completed total synthesis of dictyodendrin C (3) and D (4). In conclusion, we have developed the unprecedented one-pot benzyne-mediated indoline formation-cross coupling sequence via transmetallation to a copper species. This methodology provides direct access to the highly substituted indoline, which would be applicable to various nitrogen-containing heterocyclic compounds. By utilization of our methodology, we have established a highly flexible synthetic route by the introduction of the peripheral segments on the pivotal indole intermediate in a modular fashion, which enabled us to synthesize dictyodendrins A-E(1-5) systematically.Symposium on the chemistry of natural products, Sep. 2011, Symposium on the Chemistry of Natural Products, symposium papers, (53) (53), 253 - 258, Japanese
- Sep. 2011, CHEMISTRY LETTERS, 40(9) (9), 959 - 961, English[Refereed]Scientific journal
- Wiley Blackwell, Jul. 2011, Organic Syntheses, 88, 152 - 161, English[Refereed]Scientific journal
- Wiley Blackwell, Jul. 2011, Organic Syntheses, 88, 388 - 397, English[Refereed]Scientific journal
- Mar. 2011, HETEROCYCLES, 82(2) (2), 1633 - +, EnglishScientific journal
- Feb. 2011, CHEMISTRY-AN ASIAN JOURNAL, 6(2) (2), 560 - 572, English[Refereed]Scientific journal
- Jan. 2011, SYNLETT, 2011(1) (1), 73 - 76, EnglishScientific journal
- Nov. 2010, ORGANIC LETTERS, 12(22) (22), 5196 - 5199, English[Refereed]Scientific journal
- Mar. 2010, SYNLETT, (5) (5), 822 - 826, EnglishScientific journal
- 2010, CHEMICAL COMMUNICATIONS, 46(15) (15), 2641 - 2643, English[Refereed]Scientific journal
- 2010, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 49(34) (34), 5925 - 5929, English[Refereed]Scientific journal
- Mar. 2009, 東京大学学位論文, Englishヨウ化銅を用いる芳香族アミノ化反応を基盤とした(+)-ヤタケマイシンの不斉全合成Doctoral thesis
- 2009, Org. Synth., 86, 130 - 140, EnglishProtection of Diols with p-(tert-Butyldimethylsilyloxy)benzylidene Acetal and Its Deprotection: (4-((4R,5R)-4,5-Diphenyl-1,3-dioxolan-2-yl)phenoxy)(tert-butyl)dimethylsilane[Refereed]Scientific journal
- Dec. 2008, TETRAHEDRON, 64(49) (49), 11230 - 11236, English
- Aug. 2008, SYNLETT, (13) (13), 1977 - 1980, English[Refereed]Scientific journal
- Aug. 2008, SYNLETT, (13) (13), 1977 - 1980, EnglishScientific journal
- 2008, CHEMISTRY-AN ASIAN JOURNAL, 3(2) (2), 296 - 309, English[Refereed]Scientific journal
- (+)-Yatakemycin (1), which was isolated from a culture broth of Streptomyces sp. TP-A0356, is an antitumor antibiotic that has a characteristic dienone cyclopropane ring found in duocarmycins and CC-1065. Among them, 1 has been shown to exhibit the most potent activity, and therefore has attracted a great deal of attention. The first total synthesis along with the revision of its structure and determination of the absolute configuration has recently been reported by Boger and co-workers. Herein, we describe an efficient total synthesis of 1 utilizing our copper-mediated amination for the construction of all five aryl-nitrogen bonds, allowing us to conduct a sub-gram-scale preparation of 1 in 16% overall yield over 17 steps (longest linear steps from the known starting compound 6). Synthesis of the left segment 3 commenced with dibromination of 6. Removal of the TFA group, and subsequent oxidation provided dihydroisoquinoline 7, which was readily converted to the cyclization precursor 9. The first amination reaction of 9 afforded indoline 10 with retention of the other bromo group. After conversion to the dehydroamino ester 12, the second amination was performed to provide dihydropyrroloindole 13. The Ns group and benzyl ester in 13 were then converted to Fmoc group and a methanethiol ester, respectively. Finally, an Fmoc-directed, regioselective demethylation was performed with BCl_3 to furnish the left segment 3. Our amination also proved to be highly effective for the construction of the middle segment 4. Cleavage of (S)-epichlorohydrin (18) with 2,6-dibromophenyllithium species 17 provided chlorohydrin 19, which was then converted to amination precursor 21. The crucial aryl amination took place smoothly to give tetrahydroquinoline 22. After Mizoroki-Heck reaction with a dehydroalanine derivative 23 and removal of the nosyl group, bromo group was introduced regioselectively. The second amination reaction at the sterically hindered position was achieved by using a stoichiometric amount of CuI to furnish the middle segment 4. The right-hand segment 5 was also prepared in a straightforward manner by using the aryl amination strategy. Three segments thus obtained were assembled to complete the total synthesis. After coupling of the middle segment 4 with the right segment 5, TBS ether 32 was converted into the mesylate 33. Subsequent hydrolysis provided 34, which was subjected to the condensation conditions with 3 without isolation. Two benzyl groups were then removed with BCl_3, in the presence of excess pentamethylbenzene as a scavenger of benzyl cation. Finally, spirocyclopropanation was carried out according to Boger's conditions to furnish (+)-1, which was identical in all respects to the natural product.Symposium on the chemistry of natural products, Sep. 2006, Symposium on the Chemistry of Natural Products, symposium papers, (48) (48), 175 - 180, Japanese
- Jun. 2006, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 128(22) (22), 7136 - 7137, English[Refereed]Scientific journal
- Feb. 2004, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 77(2) (2), 347 - 355, English[Refereed]Scientific journal
- Dec. 2003, ORGANIC LETTERS, 5(26) (26), 4987 - 4990, English[Refereed]Scientific journal
- Wiley-VCH Verlag, 01 Oct. 2020, Asian Journal of Organic Chemistry, 9(10) (10), 1548 - 1561, EnglishBook review
- 02 Nov. 2015, 複素環化学討論会講演要旨集, 45th, 311 - 312, Japaneseラジカル転位環化反応を用いた(-)‐Histrionicotoxinの全合成
- Mar. 2015, SYNTHESIS-STUTTGART, 47(5) (5), A42 - A45, EnglishTotal Synthesis of (-)-Haouamine B Pentaacetate and Structural Revision of Haouamine BOthers
- 27 Oct. 2014, 有機合成シンポジウム講演要旨集, 106th, 52 - 53, Japanese(-)‐Penitrem Eの合成研究
- 22 Oct. 2014, 反応と合成の進歩シンポジウム講演要旨集, 40th, 100, Japaneseラジカル転位環化反応を用いるアザスピロ環の不斉構築を基盤としたHistrionicotoxinの合成研究
- 06 Jun. 2014, シンポジウム「モレキュラー・キラリティー」講演要旨集, 2014, (JA)103,(EN)102, Japaneseラジカル転位環化反応を用いたHistrionicotoxin類の合成研究
- 2014, 化学, 69(2) (2), 68 - 69, Japanese不安定な七員環をいかにつくるか?アセチルアラノチンの全合成[Refereed][Invited]Introduction commerce magazine
- 2014, CHEMICAL COMMUNICATIONS, 50(89) (89), 13650 - 13663, English[Refereed][Invited]Introduction scientific journal
- Oct. 2013, YAKUGAKU ZASSHI-JOURNAL OF THE PHARMACEUTICAL SOCIETY OF JAPAN, 133(10) (10), 1065 - 1078, Japanese[Refereed][Invited]Book review
- Sep. 2013, JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN, 71(9) (9), 926 - 934, Japanese[Refereed][Invited]Introduction scientific journal
- 02 Jun. 2012, 万有生命科学振興国際交流財団仙台シンポジウム, 23rd, 62, Japanese不斉転写型ラジカル転位環化反応を利用した(-)‐HTXの合成研究
- 30 May 2012, 有機合成シンポジウム講演要旨集, 101st, 113 - 116, Japanese不斉転写型ラジカル転位環化反応を利用した(-)‐Histrionicotoxinの合成研究
- 05 Mar. 2012, 日本薬学会年会要旨集, 132nd(2) (2), 111, Japaneseラジカル転位環化反応を利用した(-)‐Histrionicotoxinの合成研究
- 05 Mar. 2012, 日本薬学会年会要旨集, 132nd(2) (2), 140, JapanesePenitrem Eの合成研究
- 05 Mar. 2012, 日本薬学会年会要旨集, 132nd(2) (2), 219, JapanesePetrosinの不斉全合成および抗HIV活性に関する構造活性相関研究
- Histrionicotoxin (1) and perhydrohistrionicotoxin (2), are non-competitive blockers of nicotinic acetylcholine-acceptors. The important bioactivity and the characteristic azaspirocyclic skeleton have attracted considerable interests from the synthetic community. However, there are few effective methods for enantiocontrolled construction of the azaspirocyclic ring. Herein, we report a diastereoselective construction of the core six-membered spirolactam utilizing a radical translocation-cyclization strategy and application to a total synthesis of (-)-2. In our preliminary experiments, the radical reaction using enantiomerically pure lactam 6 resulted in significant decrease of the enantiomeric purity, which indicated inversion of the sp^3 radical center generated via 1,5-hydrogen radical shift was much faster than cyclization. Based on these results, we considered a stereoselective radical reaction with chiral-transfer from other stereocenter introduced on the side chain. With this idea in mind, we examined radical reaction with diastereomeric 16 or 19 having the same chiral side chain. As we expected, the reactions of both compounds gave the same 18 albeit in low yield probably due to the undesired radical translocation to the a-position of the silyloxy group. The low yielding problem was circumvented by conducting the reaction with ketal 22 with no hydrogen. Encouraged by this successful result, we then investigated the diastereoselective radical reaction of a substrate with a chiral ketal moiety derived from a C_2-symmetrical diol. Among a variety of diols tested, we found that 2,4-pentanediol was effective for achieving high enantiomeric excess. Based on the formation of the azaspirocyclic compound 31, we accomplished a total synthesis of (-)-perhydrohistrionicotoxin (2).Symposium on the Chemistry of Natural Products Steering Committee, 2012, Symposium on the Chemistry of Natural Products, symposium papers, 54(0) (0), 133 - 138, Japanese
- 2012, 日本薬学会東北支部大会講演要旨集, 51st, 32, JapanesePetrosinの不斉全合成および抗HIV活性に関する構造活性相関研究
- 05 Mar. 2011, 日本薬学会年会要旨集, 131st(2) (2), 143, Japanese(-)‐および(+)‐petrosinの全合成
- Oct. 2010, Yuki Gosei Kagaku Kyokaishi/Journal of Synthetic Organic Chemistry, 68(10) (10), 1036 - 1046, Japanese
- Oct. 2010, JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN, 68(10) (10), 1036 - 1046, Japanese[Refereed]Introduction scientific journal
- 14 Sep. 2010, 複素環化学討論会講演要旨集, 40th, 73 - 74, Japanese(-)および(+)‐Petrosinの全合成
- 02 Sep. 2010, 有機合成化学セミナー講演予稿集, 27th, 112, Japanese(-)および(+)‐Petrosinの全合成
- Petrosin (1), isolated as a racemate from the marine sponge Petrosia seriata by Braekman in 1982, by and Kitagawa and Kobayashi in 1989, independently, is known to possess anti-HIV activity by inhibitions of reverse transcriptase and giant cell formation. The first racemic total synthesis of 1 has been reported by Heathcock and co-workers in 1994, who also confirmed that all stereocenters of the quinolizidine rings easily epimerized via retro-Mannich and Mannich reaction. Since the anti-HIV activity of each enantiomer has not yet been investigated, we initiated synthetic studies on petrosin in optically active form to examine the bioactivity between each enantiomer. First, optically active hemiaminal 6, prepared via desymmetrization of prochiral 1,3-diol, was treated with ketene silyl acetal 7 in the presence of catalytic TBSOTf to provide the desired product 5. Vinyl iodide 19 was prepared from 5 via modification of the side chain. Union of the fully elaborated monomer segments 5 and 19 was conducted by Suzuki-Miyaura coupling to afford dimer 20 in 89% yield. Stereoselective constuction of the quinolizidine rings was then conducted by aza-Michael reaction. The crucial formation of the 16-membered ring was effectively executed by ring-closing metathesis with the 2^Symposium on the chemistry of natural products, 01 Sep. 2010, 天然有機化合物討論会講演要旨集, 52nd(52) (52), 229 - 234, Japanese
generation Grubbs catalyst. Based on the Grubb's modification, we added p-quinone to avoid isomerization of C-C double bond. Finally, the double bond was reduced under hydrogenation conditions to give (-)-petrosin (1). The optical purity of the synthetic petrosin (>99% ee) was confirmed by Mosher's method for a diol derived from 1 by reduction of two carbonyl groups, indicating that epimerization of optically active petrosin did not proceed. We also synthesized (+)-1 in the same manner from the other enantiomer of hemiaminal 6. We then evaluated inhibitoty activity against syncytium formation. While a significant difference was not observed between each enantiomer, the partial structure 13 exhibited no inhibitory activity against giant cell formation. The results indicated that the dimeric structure would be essential for the bioactivity. - 05 Mar. 2010, 日本薬学会年会要旨集, 130th(2) (2), 141, Japanese(±)‐Lepadiformine Aの全合成
- 2010, ファルマシア, 46(6) (6), 548 - 549, Japaneseアリル位C-H酸化が切り開くマクロリド合成の新展開[Refereed]Introduction scientific journal
- 10 Nov. 2009, メディシナルケミストリーシンポジウム講演要旨集, 28th, 170 - 171, Japanese抗HIV活性を示す(-)‐Petrosinの不斉全合成
- 25 Sep. 2009, 複素環化学討論会講演要旨集, 39th, 37 - 38, JapaneseSynthetic Studies on(-)-Histrionicotoxin by Radical Translocation-Cyclization
- 19 Sep. 2009, 化学系学協会東北大会プログラムおよび講演予稿集, 2009, 73, JapaneseLepadiformine類の合成研究
- 11 Sep. 2009, 有機合成化学セミナー講演予稿集, 26th, 89, Japanese9環性インドールアルカロイドPenitrem Eの合成研究
- 05 Mar. 2009, 日本薬学会年会要旨集, 129th(2) (2), 110, Japanese9環性インドールアルカロイドPenitrem Eの合成研究
- 2009, 有機合成シンポジウム講演要旨集, 95th, 145 - 148, JapanesePetrosinの全合成
- Apr. 2008, JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN, 66(4) (4), 387 - 388, Japanese[Refereed]Book review
- 05 Mar. 2008, 日本薬学会年会要旨集, 128th(2) (2), 15, Japanese抗HIV作用を持つPetrosinの合成研究
- 05 Mar. 2008, 日本薬学会年会要旨集, 128th(2) (2), 137, Japanese(-)‐ヒストリオニコトキシンの合成研究
- 2008, 日本薬学会東北支部大会講演要旨集, 47th, 20, JapaneseLepadiformine類の合成研究
- 2008, 日本薬学会東北支部大会講演要旨集, 47th, 20, Japanese(-)‐Histrionicotoxinの合成研究
- 2007, 日本薬学会東北支部大会講演要旨集, 46th, 19, Japanese抗HIV作用を持つPetrosinの合成研究
- Joint work, 化学同人, 2011, Japanese天然物合成で活躍した反応 実験のコツとポイントScholarly book
- Joint work, 化学同人, 2009, Japanese天然物の全合成 2000〜2008(日本)Scholarly book
- Joint work, 化学同人, 2005, Japanese演習で学ぶ有機反応機構Scholarly book
- 日本薬学会北陸支部 特別講演会, Dec. 2018, Japanese, Domestic conference不安定カルボアニオンの制御を基盤とするヘテロ芳香族化合物の官能基化(招待講演)[Invited]Invited oral presentation
- 第4回近畿薬学シンポジウム:化学系の若い力, Sep. 2018, Japanese, Domestic conferenceハロゲンダンスの制御を基盤とするヘテロ芳香族化合物の官能基化[Invited]Invited oral presentation
- 第67回高分子討論会, Sep. 2018, Japanese, 高分子学会, 北海道大学, Domestic conference機能性チオフェンの構造設計と精密重合[Invited]Invited oral presentation
- The 22th International Symposium on Advanced Display Materials and Devices (ADMD 2018), Jul. 2018, English, Ulsan National Institute of Science and Gechnology (UNIST), Jeju, Korea, International conferenceSynthesis of water-soluble regioregular polythiophenes[Invited]Invited oral presentation
- 日本化学会第98春季年会, Mar. 2018, Japanese, 日本化学会, 日本大学船橋キャンパス, Domestic conferenceブロモチオフェンの金ナノ粒子上におけるハロゲンダンスOral presentation
- International Congress on Pure & Applied Chemistry (ICPAC) 2018, Mar. 2018, English, Siem Reap, Cambodia, International conferenceRecent Development of Halogen Dance[Invited]Invited oral presentation
- 新学術領域研究「反応集積化が導く中分子戦略:高次生物機能分子の創製平成29年度第5回成果報告会, Jan. 2018, Japanese, 大阪大学豊中キャンパス, Domestic conferenceハロゲンダンスを基盤としたヘテロ芳香族化合物の集積型官能基化Oral presentation
- The First International Conference on Automated Flow and Microreactor Synthesis(ICAMS-1), Jan. 2018, English, 大阪, International conferenceDeprotonation of Dibromothiophenes Controlled by Flash ChemistryPoster presentation
- The 11th International Symposium on Integrated Synthesis, Nov. 2017, English, 淡路島, International conferenceSynthesis of Thienoindoles by Halogen Dance and Ligand-Controlled One-Pot Sequential Coupling ReactionsPoster presentation
- The 11th International Symposium on Integrated Synthesis, Nov. 2017, English, 淡路島, International conferenceSynthesis of Furan-Dimer Based BiopolyesterPoster presentation
- The 11th International Symposium on Integrated Synthesis, Nov. 2017, English, 淡路島, International conferenceRegiocontrolled Halogen Dance of α-Bromothiophenes and α-BromofuransPoster presentation
- The 11th International Symposium on Integrated Synthesis, Nov. 2017, English, 淡路島, International conferenceDeprotonation of Dibromothiophenes Controlled by Flash ChemistryPoster presentation
- 第35回メディシナルケミストリーシンポジウム, Oct. 2017, Japanese, 名古屋大学, Domestic conferenceハロゲンダンスを用いる多置換ヘテロ芳香族化合物の合成Poster presentation
- 第34回有機合成化学セミナー, Sep. 2017, Japanese, 金沢市文化ホール, Domestic conference新規合成方法論の開発を基盤とする含窒素高次縮環天然物の全合成(奨励賞受賞講演)[Invited]Invited oral presentation
- GSCシンポジウム, Jul. 2017, Japanese, 東京国際フォーラム・ホール, Domestic conference高歪み中間体の効率的発生方法の開発Poster presentation
- 新学術領域研究「反応集積化が導く中分子戦略:高次生物機能分子の創製平成29年度第4回成果報告会, Jul. 2017, Japanese, 京都大学桂キャンパス船井講堂, Domestic conferenceハロゲンダンスを基盤としたヘテロ芳香族化合物の集積型官能基化Poster presentation
- 第111回有機合成シンポジウム, Jun. 2017, Japanese, 有機合成化学協会, 岡山大学津島キャンパス, Domestic conferenceマグネシウムビスアミドを用いるシクロアルキンの脱プロトン的発生法の開発Oral presentation
- MPI-KobeU-RIKEN Joint Symposium, Feb. 2017, English, International conferenceControl of transient anion species for synthesis of multiply substituted heteroaromatic compounds[Invited]Invited oral presentation
- 高分子研究会(神戸), Jul. 2016, Japanese, 高分子学会関西支部, 神戸県民会館, Domestic conferenceフルフラールを原料とする共役系ポリマーの合成Poster presentation
- Molecular Chirality Asia 2016 – Chiral Science and Technology: From Asia to the World –, Apr. 2016, English, Knowledge Capital Congress Convention Center, International conferenceKinetic Resolution of Heterobiaryl Derivatives with Winding-vine-shaped Molecular AsymmetryPoster presentation
- 日本化学会第96春季年会, Mar. 2016, Japanese, 日本化学会, 同志社大学, Domestic conference炭素-塩素結合をもつチオフェン誘導体のC-H結合におけるカップリング反応によるチオフェン-チオフェン結合の生成Oral presentation
- 日本化学会第96春季年会, Mar. 2016, Japanese, 日本化学会, 同志社大学, Domestic conferenceマグネシウムビスアミドを用いるブロモチオフェン類のハロゲンダンスOral presentation
- 日本化学会第96春季年会, Mar. 2016, Japanese, 日本化学会, 同志社大学, Domestic conferenceマグネシウムビスアミドを用いるエノールトリフラートの脱プロトン的シクロアルキン発生法の開発Oral presentation
- 日本化学会第96春季年会, Mar. 2016, Japanese, 日本化学会, 同志社大学, Domestic conferenceハロゲンダンスを利用したポリアリールチオフェン類の効率的合成法の開発Oral presentation
- 日本化学会第96春季年会, Mar. 2016, Japanese, 日本化学会, 同志社大学, Domestic conferenceつるまき状分子不斉を有するビチオフェン誘導体の速度論的光学分割Oral presentation
- 日本化学会第96春季年会, Mar. 2016, Japanese, 日本化学会, 同志社大学, Domestic conferenceつるまき状分子不斉を有するビスイミダゾール誘導体の速度論的光学分割Oral presentation
- 日本化学会第96春季年会, Mar. 2016, Japanese, 日本化学会, 同志社大学, Domestic conferenceチオフェン誘導体のC-Hカップリング重合における配位子効果の検討Oral presentation
- 日本化学会第96春季年会, Mar. 2016, Japanese, 日本化学会, 同志社大学, Domestic conferenceチオフェン誘導体のC-Hカップリング重合におけるモノマー構造多様性の検討Oral presentation
- ヘテロ原子部会平成27年度第3回懇話会, Feb. 2016, Japanese, Domestic conferenceカルボアニオンの反応性制御を基盤とする多置換ヘテロ芳香族化合物の合成[Invited]Invited oral presentation
- 分子イメージングセミナー RIKEN Molecular Imaging Seminar, Sep. 2015, Japanese, Domestic conference特異な骨格を有するアルカロイド類の合成研究[Invited]Invited oral presentation
- 岡山大学異分野融合研究育成支援事業「有機合成を基盤とした生体機能制御分子の創製」第2回講演会, Jul. 2015, Japanese, Domestic conference特異な骨格を有するアルカロイド類の合成研究[Invited]Invited oral presentation
- ICOB-5&ISCNP-25 IUPAC, International Conference on Biodiversity and Natural Product, 2006Total Synthesis of (+)-YatakemycinPoster presentation
- 第48回天然有機化合物討論会, 2006(+)-Yatakemycinの全合成
- ICOB-5&ISCNP-25 IUPAC, International Conference on Biodiversity and Natural Product, 2006Total Synthesis of (+)-YatakemycinPoster presentation
- 第48回天然有機化合物討論会, 2006(+)-Yatakemycinの全合成
- 2005環太平洋国際化学会議, 2005Synthetic Studies on (+)-YatakemycinPoster presentation
- 第87回有機合成シンポジウム, 2005(+)-ヤタケマイシンの全合成研究
- 第87回有機合成シンポジウム, 2005(+)-ヤタケマイシンの全合成研究
- 2005環太平洋国際化学会議, 2005Synthetic Studies on (+)-YatakemycinPoster presentation
- 国際複素環化学会
- The Society of Synthetic Organic Chemistry, Japan
- The Chemical Society of Japan
- The Pharmaceutical Society of Japan
- 近畿化学協会
- 日本薬学会
- 日本化学会
- 有機合成化学協会
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), Kobe University, Apr. 2019 - Mar. 2023, Principal investigatorDevelopment of Direct Functionalization of Heteroaromatic Compounds Based on Trapping of the Short-lived Carbanions2020年度は、前年度に達成したルキアノールやニンガリン、ラメラリン類などのピロール天然物の全合成において、鍵反応として用いたブロモピロールのハロゲンダンスの一般性を検証した。特に、ピロール窒素上の置換基として、スルホニル基を用いると円滑にハロゲンダンスが進行することがわかった。また、予備的検討として、精密in situトランスメタル化にも成功し、ハロゲンダンスに含まれる二種類の有機リチウムをそれぞれ対応する有機亜鉛反応剤として利用することができた。この知見に基づき、上記ピロール天然物の合成において、課題として残されていた二つのβ位ブロモ基の位置選択的な変換反応についても、一定の解決法を提示することができた。以上の知見により、多置換ピロールの合成法を確立した。 ハロゲンダンスにおいて、反応系中で発生する短寿命炭素アニオンをin situトランスメタル化するためのハロゲン化亜鉛ジアミン錯体を10種類以上合成し、幅広いブロモアレーン類について、その有用性を検証した。その結果、チエニルリチウムと比較すると、不安定なフリルリチウムやピロリルリチウムなどの短寿命炭素アニオンにも本方法を適用できた。さらに、これまでバッチ法では捕捉できなかったハロゲンダンスの前後の不安定炭素アニオンの合成的な利用についても検討を進めたところ、アゾール類についても、本手法が有効であることがわかった。 マイクロフローリアクターを活用する、短寿命炭素アニオンの選択的な捕捉については、ジブロモチオフェンのブロモ基の置換位置によって、対応する炭素アニオンが捕捉可能かどうかを明らかにした。すなわち、2,3-ジブロモチオフェン由来の5位リチオ化体はさまざまな求電子剤で捕捉できたが、2,5-ジブロモチオフェン由来の3位リチオ化体については、条件検討にもかかわらず、ハロゲンダンスが優先することがわかった。Competitive research funding
- 公益財団法人 ハーモニック伊藤財団, 2019年度助成金, Apr. 2019 - Mar. 2021, Principal investigator高ひずみ短寿命中間体の実用的発生法の開発Competitive research funding
- 公益財団法人 総合工学振興財団, 令和元年度研究奨励, Apr. 2019 - Mar. 2020, Principal investigator高ひずみ短寿命炭化水素の実用的発生法の開発と機能性高分子の合成Competitive research funding
- 公益財団法人 京都技術科学センター, 2019年度研究開発助成, Apr. 2019 - Mar. 2020, Principal investigator精密in situトランスメタル化を鍵とするハロゲンダンスの制御Competitive research funding
- 公益財団法人 東燃ゼネラル石油研究奨励・奨学財団, 第38回(平成30年度)東燃ゼネラル石油研究奨励助成, Mar. 2019 - Mar. 2020, Principal investigator高ひずみ炭化水素前駆体の実用的合成と機能性分子の創製Competitive research funding
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), Kobe University, Apr. 2018 - Mar. 2020, Principal investigatorIntegrated Synthesis of Heteroaromatic Compounds Based on Control of Halogen Dance2019年度は、ブロモ基が分子内で動きながらワンポットで二つの結合を形成するハロゲンダンスを鍵として、ルキアノールAおよびB、ニンガリンB、ラメラリンSおよびZの全合成を達成した。二つのブロモ基を足がかりに、上部芳香環を位置選択的カップリングにより導入する集積型合成法が、関連する化合物群の合成に広く応用できることを示した。また、ハロゲンダンスの後、有機亜鉛反応剤へのトランスメタル化を経て根岸カップリングする、ラメラリン類の第二世代合成も達成した。 バッチ系にてハロゲンダンスが進行する、その他のヘテロ芳香族化合物を基質としてマイクロフロー反応を実施し、いくつかの基質においてハロゲンダンス前後の短寿命アリールリチウムを捕捉する条件を見出した。その過程で、攪拌効率が、選択性に大きく影響することも確認した。特に、バッチ型反応装置では開環反応を経て分解するチアゾールについて、マイクロフロー反応によりハロゲンダンス前の短寿命アリールリチウムを捕捉することにも成功し、フローマイクロリアクターの合成的有用性を示すことができた。 ハロゲンダンスにおいて、反応系中で発生する短寿命炭素アニオンの捕捉を検討する中で見出した、金属ジアミン錯体によるin situトランスメタル化を利用すると、フローマイクロリアクターでは選択的な捕捉が困難であった、2,5-ジブロモチオフェン由来の炭素アニオンを捕捉できた。さらに、新規金属ジアミン錯体を合成し、その他の従来合成的に利用できなかったアニオンの捕捉も実現した。Competitive research funding
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), Kobe University, Apr. 2016 - Mar. 2019, Principal investigatorEffects of amide bases on halogen dance were investigated. Compared to the conventional lithium amides, the magnesium bisamide can control halogen dance of 2,3-dibromothiophene to provide both products that are derived from the two carbanion species. In addition, magnesium amide facilitated the formation of cycloalkanes from the enol triflates, which were prepared from the corresponding ketones in one step.Competitive research funding
- 公益財団法人 川西記念新明和教育財団, 平成28年度 研究助成金, Apr. 2016 - Mar. 2018, Principal investigatorカルボアニオンの反応性制御を基盤としたワンポット連続反応の開発Competitive research funding
- 日本学術振興会, 科学研究費補助金/新学術領域研究, 新学術領域研究(研究領域提案型), 神戸大学, Apr. 2016 - Mar. 2018, Principal investigator平成29年度は、バッチ系のハロゲンダンスにおいて、マグネシウムビスアミドMg(TMP)2・2LiClが室温下、円滑にハロゲンダンスを進行させることも確認した。従来用いられていた、LiTMPなどのリチウムアミドとは異なり、反応条件を適切に選択することで、ハロゲンダンスを停止させることも可能であった。これにより、置換様式の異なる多置換チオフェン類の合成が可能になった。また、マイクロフロー反応装置を用いることにより、リチウムアミドを用いるバッチ系では不可能であった変換にも成功した。また、非対称なブロモチオフェンやブロモフランのハロゲンダンスに、置換基がおよぼす影響を検討した。その結果、エステルやアミドが配向基として作用し、従来とは異なる1,3型の転位様式でハロゲンダンスが進行することを確認した。さらに、オキサゾリンを配向基として利用することで、これまでに報告例がないブロモピロールにおいてもハロゲンダンスが円滑に進行することを明らかにした。そこで、ハロゲンダンスの長所である、官能基導入の足がかりとなるハロゲン原子(ブロモ基)が転位しながら、求電子剤と反応する合成的有用性を示すため、多置換ピロールアルカロイド類の網羅的合成経路の確立を目標として、合成研究に取り組んだ。ハロゲンダンスを経て5位に移動したリチウム種を亜鉛にトランスメタル化し、パラジウム触媒による根岸カップリングにより三環性重要中間体を得た。Competitive research funding
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), Apr. 2013 - Mar. 2016, Principal investigatorIn this study we accomplished a total synthesis of MPC1001B, antiproliferative activity against DU145 human prostate cancer cell line, based on inversion of the two stereogenic centers that were generated in the key TBAF-mediated formation of the macrolactone. Preliminary experiments on introduction of the hydroxyl group on the dihydrooxepine skeleton for the late-stage oxidation were performed using a model substrate with selenium dioxide to establish mild oxidation conditions. We also investigated construction of the partial skeleton of aconitine through formation of enone from in five steps including Birch reduction. Conversion to the corresponding silyl enol ether followed by Diels-Alder reaction provided the desired tetracyclic compound, which was converted to the secondary alcohol. The mesylate was treated with silica gel to provide the allylic alcohol as a single isomer via Wagner-Meerwein rearrangement. Synthetic studies on acochlearine was also performed.Competitive research funding
- 公益財団法人 松籟科学技術振興財団, 研究助成金, Apr. 2014 - Mar. 2015, Principal investigator植物由来アコニチンアルカロイド類の合成研究Competitive research funding
- 日本学術振興会, 科学研究費補助金/新学術領域研究, 新学術領域研究(研究領域提案型), 東北大学, Apr. 2013 - Mar. 2015, Principal investigatorC-H活性化を鍵とする直接的ヘテロ原子導入法の開発平成26年度は、すでに全合成を達成したMPC1001Bの合成経路および反応条件の最適化を行うとともに、MPC1001BからMPC1001への変換について、既知のC-H酸化反応を含めて検討を行った。すなわち、MPC1001 に含まれるジヒドロオキセピン上のヒドロキシ基の導入について、合成終盤におけるアリル位酸化を検討した。その結果、二酸化セレンを用いた場合に、ジスルフィド結合がほぼ保持され、最終段階における酸化剤として有用であることがわかった。 タラチサミンおよびアコニチンの有する左部含窒素構造の構築を検討した。従来、多段階を必要としていた含窒素環状構造の構築について、短工程化を目的として各変換について検討した。その結果、ラジカル的連続反応を見出し、酸化的炭素炭素結合の形成に成功した。本反応を見出したことで、今後、これらアルカロイド類の右部の合成研究が円滑に行われると考えている。 また、複雑な縮環インドール骨格を有するアルカロイド、ペニトレム類の合成研究にも取り組んだ結果、パラジウム触媒を用いたC-H活性化(Catellani反応)を用いて、インドール4,5位に6員環炭素骨格を一挙に導入することに成功した。本変換により、その後の合成研究に必要な化合物を十分に供給することができた。最終的に、(2+2)環化付加反応を経て、ペニトレム類に共通するシクロブタン環を構築し、ペニトレムEの左側部分構造の合成に成功した。Competitive research funding
- 公益財団法人 薬学研究奨励財団, 研究助成金グループA, Apr. 2013 - Mar. 2014, Principal investigator有用な生物活性を有するジチオジケトピペラジン天然物の合成研究Competitive research funding
- 公益財団法人 アステラス病態代謝研究会, 研究助成金, Apr. 2012 - Mar. 2013, Principal investigator動的速度論的分割を鍵とするアザスピロ環の不斉構築Competitive research funding
- 公益財団法人 東京生化学研究会, 研究奨励金(Ⅰ), Apr. 2012 - Mar. 2013, Principal investigator多様な誘導体合成を指向した新規ジチオジケトピペラジン天然物の網羅的全合成Competitive research funding
- 科学研究費補助金/若手研究(B), Apr. 2011 - Mar. 2013, Principal investigatorマグネシウムビスアミドを用いる新規ベンザイン発生法の開発と生理活性天然物の全合成Competitive research funding
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Grant-in-Aid for Young Scientists (B), Tohoku University, 2011 - 2012A synthetic method for the construction of multi-substituted nitrogen heterocycles such as indolines and carbazoles was established based on the development of mild generation of benzyne species using magnesium bisamide. The utility of this method was demonstrated by the total synthesis of heptaphylline and batzelline family as well as by its broad scope of substrates and electrophiles used in the reaction.
- 公益信託 三菱化学研究奨励基金, 平成22年度研究助成金, Apr. 2010 - Mar. 2011, Principal investigator不斉転写型ラジカル反応を鍵とするHTXの合成研究Competitive research funding
- 公益財団法人 アステラス病態代謝研究会, 研究助成金, Apr. 2010 - Mar. 2011, Principal investigatorベンザインを経由するワンポット連続的環化ー官能基化に基づく多置換複素環骨格構築法の開発と生理活性天然物の革新的全合成Competitive research funding
- 科学研究費補助金/若手研究(B), Apr. 2009 - Mar. 2011, Principal investigatorベンザインを基軸とする多置換複素環化合物の新規合成法の開発と天然物合成への展開Competitive research funding
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Grant-in-Aid for Young Scientists (B), Tohoku University, 2009 - 2010Synthetic methodology for multi-substituted heterocycles was developed utilizing the high reactivity of benzyne intermediate. Magnesium bisamide was proved to be the best base for the benzyne generation and nucleophilic addition to construct heterocyclic skeletons. The resulting anion species reacted with a variety of electrophiles to give functionalized heteroaromatic compounds. The tricyclic skeleton of isobatzelline and discorhabdins was constructed using the reaction conditions.
- 財団法人 薬学研究奨励財団, 研究者の海外派遣に対する補助, Jun. 2009 - Jun. 2009, Principal investigator第41回アメリカ有機化学シンポジウムCompetitive research funding
- 科学研究費補助金/スタートアップ, May 2007 - Mar. 2009, Principal investigatorテロメラーゼ阻害活性を有するディクティオデンドリン類の合成研究Competitive research funding
- Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (Start-up), Grant-in-Aid for Young Scientists (Start-up), Tohoku University, 2007 - 2008本研究では、海綿から単離・構造決定されたテロメラーゼ阻害活性天然物ディクティオデンドリン類の合成研究を行った。その結果、ベンザインの高い反応性を利用する多置換インドリンの新規合成法を開発し、ディクティオデンドリンBの効率的全合成に成功した。さらに、ディクティオデンドリンAの世界初の全合成も達成した。本合成経路は合成終盤にさまざまな置換基を収束的に導入できることから、ディクティオデンドリン類の誘導体合成に応用可能である。
- 日本学術振興会, 科学研究費補助金/特別研究員奨励費, 特別研究員奨励費, Apr. 2006 - Apr. 2007, Principal investigatorヤタケマイシンをはじめとする複雑な含窒素環状化合物の合成研究申請者は当研究室で開発された芳香族アミノ化反応を鍵反応として本化合物の合成研究を行うことで、これまで困難であった複雑な構造を有する含窒素環状化合物に対する一般性の高い新規合成法を確立できると考えている。前年度の研究成果として、強力なDNAアルキル化能を持つグラムスケールにてヤタケマイシンの全合成を達成している。本年度は、ヤタケマイシンの合成研究で得られた知見をもとに、海産性の天然物として初めてテロメラーゼ阻害活性(IC_<100>=50μM)を示すディクティオデンドリン類の合成研究を行った。本化合物群は二つの窒素原子を含む高度に置換された芳香環を有しており、これらが非常に電子豊富であることから、古典的な手法では合成がきわめて困難である。まずはディクティオデンドリン類全てに共通する4環性コア骨格の構築を当面の目標とした。100グラムスケールにて容易に調製可能なトリハロベンゼンから3工程で得られるスルホンアミドに対し、芳香族アミノ化反応が片方のプロモ基を完全に保持したまま、ほぼ定量的に進行することを見いだした。ここから、残されたブロモ基を足がかりとして種々のクロスカップリング反応を検討した結果、インドリン骨格を含む基質の場合は全く反応が進行しなかったが、インドール骨格へ酸化された基質を用いると望みのビアリール体を合成できた。また、続くアジドの熱分解も最適化は行っていないものの中程度の収率で4環性コア骨格を構築することに成功した。今後は残されたパラアニシル基の導入を経て全合成が達成できるものと考えている。Competitive research funding
- 脱水溶媒の調製方法特願2019-034680, 27 Feb. 2019, 株式会社神鋼環境ソリューション, 国立大学法人神戸大学, 特開2020-138922, 03 Sep. 2020Patent right
- 細胞内送達ベヒクル特願2020-027873, 21 Feb. 2020, キリンホールディングス株式会社, 国立大学法人 東京大学, 国立大学法人東北大学, 特開2020-097622, 25 Jun. 2020, 特許第6666673号, 26 Feb. 2020Patent right
- フランオリゴマーポリエステルおよびその前駆体特願2017-045892, 10 Mar. 2017, 国立大学法人神戸大学, 特開2018-150415, 27 Sep. 2018Patent right