Tartrate-derivedbioxazolineligands, which form a five-membered chelate ring with metals, were evaluated for use in the asymmetric allylic alkylation (AAA) reactions of various symmetrical and unsymmetrical allylacetates. Excellent enantioselectivities were achieved by using both symmetrical and unsymmetrical allylacetates.
Synthesis of chiral S , N -thioimidazoline ligands for palladium-catalyzed asymmetric allylic alkylations
作者:Xin-Qi Hao、Ming-Zhan Shen、Ning-Ge Jian、Wei Pang、Xiao-Jing Shen、Xinju Zhu、Mao-Ping Song
DOI:10.1016/j.tetasy.2016.01.015
日期:2016.3
A series of chiral S,N-thioimidazoline ligands have been synthesized using 2-bromobenzoic acid or 1-bromo-2-naphthoic acid as starting materials. The obtained ligands were evaluated in the Pd-catalyzed asymmetric allylic alkylations and exhibited high catalytic efficiency: yields of up to 94% and enantioselectivities of up to 86% were achieved under the optimized conditions. (C) 2016 Elsevier Ltd. All rights reserved.