Catalytic Asymmetric Acylation of (Silyloxy)nitrile Anions
作者:David A. Nicewicz、Christopher M. Yates、Jeffrey S. Johnson
DOI:10.1002/anie.200353354
日期:2004.5.10
Enantioselective Cyanation/Brook Rearrangement/<i>C</i>-Acylation Reactions of Acylsilanes Catalyzed by Chiral Metal Alkoxides
作者:David A. Nicewicz、Christopher M. Yates、Jeffrey S. Johnson
DOI:10.1021/jo049164e
日期:2004.10.1
New catalytic enantioselective cyanation/1,2-Brook rearrangement/C-acylation reactions of acylsilanes (4) with cyanoformate esters (7) are described. The products of the reaction are fully substituted malonic acid derivatives (8). Catalysts for this transformation were discovered via a directed candidate screen of 96 metal-ligand complexes. Optimization of a (salen)aluminum complex revealed significant remote electronic effects and concentration effects. The scope of the reaction was investigated by using a number of aryl acylsilanes and cyanoformate esters. Chemoselective reduction of the reaction products (8) afforded new enantioenriched alpha-hydroxy-alpha-aryl-beta-amino acid derivatives (32-34) and beta-lactams (35 and 36). This reaction provides a simple method for the construction of new nitrogen-containing enantioenriched chiral building blocks.