Preparation Of Novel Glycosyl Metal Nano Particles And Research In Organic Synthesis

Transition metal-based homogenous catalysts has attracted a great deal of attention and showed remarkable activity and selectivity in these couplings. However, the difficulty of separating the homogeneous catalysts from reaction medium restricts their applications in the pharmaceutical industry. Alternatively, metal catalysts anchored on a heterogeneous support have received tremendous attention recently in cross-coupling. The heterogeneous processes have advantages such as ease of separation of the product, reusability of the catalyst, better steric control of the reaction intermediate and so on.However, the activities of heterogeneous catalysts are generally lower than those of their homogeneous counterparts, due to the lower dimensionality of the interaction between the substrates and the catalyst surface. In contrast, metal nanoparticle catalysts are advantageous in terms of high activity, high stability, and efficient recovery. Until now a large number of deficiencies still existing in the rational design and synthesis of high active and recoverable catalysts. Therefore, preparation of novel metal nanoparticles and research in organic synthesis are extremely important.We report a series of novel carbohydrate-derived pyridyl-triazole@ palladium nanoparticles which were synthesized by reaction of azidoglycosides with 2-ethynylpyridine via a click chemistry. These nanoparticles were fully characterized by 1H and 13C NMR, elemental analysis, transmission electron microscopy (TEM) and thermogravimetric analysis (TG). Their use in the palladium-catalyzed C-C coupling such as Suzuki-Miyaura coupling.We herein report novel carbohydrate-derived pyridyl-triazole@palladium nano particles and Platinum nanoparticles. in the same ligand under different metal catalysts in the oxidation of olefins Wacker reaction, can be selectively oxidized to ketones and aldehydes. In the optimal conditions for the substrate,13 kinds of ketone and 13 kinds of aldehyde compounds was synthesized, its possible mechanism was studied.