Synthesis of novel carbohydrate-based valine-derived formamide organocatalysts by CuAAC click chemistry and their application in asymmetric reduction of imines with trichlorosilane
作者:Xin Ge、Chao Qian、Xinzhi Chen
DOI:10.1016/j.tetasy.2014.10.003
日期:2014.11
organocatalysts combining carbohydrate and N-formyl-l-valine derivatives were prepared by CuII-catalyzed diazotransfer and CuI-catalyzed azide–alkyne 1,3-dipolar cycloaddition CuAACclickchemistry. It was found that the carbohydrate-based valine-derived formamide organocatalyst had high catalytic activity for the asymmetric reduction of imines with trichlorosilane. The reduction can proceed at room
Evolution of chiral Lewis basic N-formamide as highly effective organocatalyst for asymmetric reduction of both ketones and ketimines with an unprecedented substrate scope
作者:Li Zhou、Zhouyu Wang、Siyu Wei、Jian Sun
DOI:10.1039/b703307a
日期:——
L-Pipecolinic acid derived Lewis basic N-formamide has been developed as a first highly effective catalyst for the asymmetric reduction of aromatic and aliphatic ketones as well as aromatic and aliphatic ketimines in good to high enantioselectivity.
Synthesis of Group 4 Metal Complexes Stabilized by an Amine-Bridged Bis(phenolato) Ligand and Their Catalytic Behavior in Intermolecular Hydroamination Reactions
bis(phenolato) ligand, have been synthesized and characterized. Although 1 and 2 were inactive in catalyzing intermolecularhydroamination reactions, cationic complexes generated in situ from treatment of 1 and 2 with borate [Ph3C][B(C6F5)4], respectively, were found to be highly active. In general, excellent yields (up to >99%) and 100% regioselectivity for a broad range of terminalalkynes and anilines
Pentacoordinate zirconium complexes 5 and 7 stabilized by amine-bridged bis(phenolato) ligands are more active than hexacoordinate complexes 1–4 in catalyzing intermolecular hydroamination reactions.
Rationally-Designed<i>S-</i>Chiral Bissulfinamides as Highly Enantioselective Organocatalysts for Reduction of Ketimines
作者:Dong Pei、Yu Zhang、Siyu Wei、Meng Wang、Jian Sun
DOI:10.1002/adsc.200700504
日期:2008.3.7
example of S-chiral organocatalysts, that are highly efficient and enantioselective in substoichometric amounts, and which use a chiral monosulfinamide group as Lewis base to activate trichlorosilane (HSiCl3) to reduce N-arylketimines. A plausible mechanism involving two molecules of the monosulfinamde catalyst for the activation of HSiCl3 prompted us to design S-chiral bissulfinamides as new catalysts