Modulation of the coordination geometries of NCN and NCNC Rh complexes for ambidextrous chiral catalysts
作者:Jun-ichi Ito、Takahiro Ishihara、Takaki Fukuoka、Siti Rokiah Binti Mat Napi、Hajime Kameo、Hisao Nishiyama
DOI:10.1039/c9cc06520b
日期:——
A chirality switch between novel NCN pincer Rh complexes and a related double cyclometalated NCNC Rh complex containing secondary amino groups is described. Their catalytic abilities were determined in asymmetric alkynylation of ethyltrifluoropyruvate, and the change in the coordination geometry of the Rh catalysts affected the stereochemistry of the products.
Thinking outside the box: A newly developed C1‐symmetric Rh/Phebox complex efficiently catalyzed the asymmetricalkynylation of α‐ketoester 1 with various aryl and alkyl substituted terminal alkynes to provide the corresponding chiral tertiary propargylic alcohols with up to 99 % ee (see scheme; TMS=trimethylsilyl).