Development of highly efficient and enantioselective hydrophosphonylations of aldehydes and ynones mediated by [5.5]-P-spirocyclic chiral triaminoiminophosphoranes as base catalysts is described. T...
Kinetic resolution of racemic α-hydroxyphosphonates by asymmetric esterification using achiral carboxylic acids with pivalic anhydride and a chiral acyl-transfer catalyst
作者:Isamu Shiina、Keisuke Ono、Takayoshi Nakahara
DOI:10.1039/c3cc44293d
日期:——
A practical protocol is developed to directly provide chiral alpha-acyloxyphosphonates and alpha-hydroxyphosphonates from (+/-)-alpha-hydroxyphosphonates utilizing the transacylation process to generate the mixed anhydrides from acid components and pivalic anhydride in the presence of organocatalysts (s-value = 33-518).
An aluminum binaphthyl Schiff base complex was found to be an efficient catalyst for enantioselective hydrophosphonylation of aldehydes. High enantioselectivities were obtained in reactions of both aromatic and aliphatic aldehydes (up to 84% and 86% ee, respectively).
Diametric Stereocontrol in Dynamic Catalytic Reduction of Racemic Acyl Phosphonates: Divergence from α-Keto Ester Congeners
作者:Michael T. Corbett、Jeffrey S. Johnson
DOI:10.1021/ja310980q
日期:2013.1.16
Ru-catalyzed asymmetric transfer hydrogenation of acyl phosphonates: reduction proceeded from the opposite face relative to that observed in the analogous reduction of α-keto esters. The first highly selective catalytic hydrogenation of acyl phosphonates was utilized in the dynamic kinetic resolution of α-aryl acyl phosphonates, providing β-stereogenic α-hydroxy phosphonic acidderivatives.