Reductive amination of triglycerides under mild conditions was achieved using a titanium oxide-supported Pt–Mo catalyst. Various triglycerides including cooking oil are transformed into their corresponding fatty amines.

Reductive amination of carboxylic acids is a green and sustainable method for alkylamine synthesis because carboxylic acids are abundant and accessible carbon sources. Herein, we present an aluminum oxide-supported platinum–molybdenum...

Abstract Iron-based heterogeneous catalysts are ideal metal catalysts owing to their abundance and low-toxicity. However, conventional iron nanoparticle catalysts exhibit extremely low activity in liquid-phase reactions and lack air stability. Previous attempts to encapsulate iron nanoparticles in shell materials toward air stability improvement were offset by the low activity of the iron nanoparticles. To overcome the trade-off between activity and stability in conventional iron nanoparticle catalysts, we developed air-stable iron phosphide nanocrystal catalysts. The iron phosphide nanocrystal exhibits high activity for liquid-phase nitrile hydrogenation, whereas the conventional iron nanoparticles demonstrate no activity. Furthermore, the air stability of the iron phosphide nanocrystal allows facile immobilization on appropriate supports, wherein TiO₂ enhances the activity. The resulting TiO₂-supported iron phosphide nanocrystal successfully converts various nitriles to primary amines and demonstrates high reusability. The development of air-stable and active iron phosphide nanocrystal catalysts significantly expands the application scope of iron catalysts.

Hydroboration of alkynes with bis(pinacolato)diboron is a useful method for the synthesis of vinyl boronate esters, which are essential intermediates in organic syntheses. Copper catalysts have been used extensively in...

A new sialic acid (Sia)-containing glycopolymer-a fluorescent probe with high-density disialic acid (diSia) on the surface of polysaccharide dextran (diSia-Dex)-was synthesized as a key molecule to regulate the Sia recognition lectins, Siglecs, that are involved in the immune system. According to our original methods, diSia was synthesized by alpha-selective sialylation, and a dextran template possessing terminal acetylenes and amino groups was prepared. A diSia and a fluorescent molecule were subsequently introduced to surface-modified dextran by Huisgen reaction and amidation, respectively. The modulatory activity of Siglec7 was evaluated by using synthetic probes. DiSia-Dex showed high binding avidity toward Siglec7, with a KD value of 5.87 x 10(-10) M, and a high inhibitory activity for the interaction between Siglec7 and a ligand (GD3), with a IC50 value of 1.0 nM. Notably, diSia-Dex was able to release Siglec7 from the pre-existing Siglec7-GD3 complex, possibly due to its unique properties of a slow dissociation rate and a high association rate. Together, these data show that diSia-Dex can be widely applicable as a modulator of Siglec7 functions.

The high productivity of oil biosynthesized by microalgae has attracted increasing attention in recent years. Due to the application of such oils in jet fuels, the algal biosynthetic pathway toward oil components has been extensively researched. However, the utilization of the residue from algal cells after oil extraction has been overlooked. This residue is mainly composed of carbohydrates ( starch), and so we herein describe the novel processes available for the production of useful chemicals from algal biomass-derived sugars. In particular, this review highlights our latest research in generating lactic acid and levulinic acid derivatives from polysaccharides and monosaccharides using homogeneous catalysts. Furthermore, based on previous reports, we discuss the potential of heterogeneous catalysts for application in such processes.

Algal biomass has received attention as an alternative carbon resource owing not only to its high oil production efficiency but also, unlike corn starch, to its lack of demand in foods. However, algal residue is commonly discarded after the abstraction of oil. The utilization of the residue to produce chemicals will therefore increase the value of using algal biomass instead of fossil fuels. Here, we report the use of algal residue as a new carbon resource to produce important chemicals. The application of different homogeneous catalysts leads to the selective production of methyl levulinate or methyl lactate. These results demonstrate the successful development of new carbon resources as a solution for the depletion of fossil fuels.

Due to the depletion of fossil fuels, biomass-derived sugars have attracted increasing attention in recent years as an alternative carbon source. Although significant advances have been reported in the development of catalysts for the conversion of carbohydrates into key chemicals (e.g., degradation approaches based on the dehydration of hydroxyl groups or cleavage of C-C bonds via retro-aldol reactions), only a limited range of products can be obtained through such processes. Thus, the development of a novel and efficient strategy targeted towards the preparation of a range of compounds from biomass-derived sugars is required. We herein describe the highly-selective cascade syntheses of a range of useful compounds using biomass-derived sugars as carbon nucleophiles. We focus on the upgrade of C2 and C3 oxygenates generated from glucose to yield useful compounds via C-C bond formation. The establishment of this novel synthetic methodology to generate valuable chemical products from monosaccharides and their decomposed oxygenated materials renders carbohydrates a potential alternative carbon resource to fossil fuels.

Synthesis of dextran-based bone tracers for in vivo imaging from a dextran-template containing terminal acetylenes and amino groups though a diethylene glycol spacer is described. The tracer was used to visualize regenerated bone in a BMP-2 installed hydrogel by magnetic resonance and optical imaging.

The development of a highly efficient cascade reaction sequence that rapidly proceeds via 12 consecutive chemical transformations in one pot has been described. This cascade reaction includes nine different chemical reactions and two opposing types of organocatalysis (Brønsted acid and phosphine catalysis) , and terminates in the formation of tetracyclic tetrahydroindolo[2,3-a]quinolizines, which resemble the core scaffold of numerous polycyclic indole alkaloids. By the biological investigation of the corresponding focused compound collections, two highly active compounds were discovered. In addition, cellular targets of the compounds were identified using fluorescent probe.