Ligand-accelerated Enantioselective Propargylation of Aldehydes via Allenylzinc Reagents
作者:Barry M. Trost、Ming-Yu Ngai、Guangbin Dong
DOI:10.1021/ol200043n
日期:2011.4.15
An enantioselective propargylation of aldehydes using an allenylzinc reagent generated in situ via a zinc-iodine exchange reaction is described. The enantioselectivity is controlled by addition of a catalytic amount of readily accessible and highly tunable amino alcohol ligand L13. A wide range of aldehydes can be propargylated to afford valuable and versatile homopropargyl alcohols in good to excellent yields with high levels of enantiopurity.
Helical Chiral 2,2′-Bipyridine <i>N-</i> Monoxides as Catalysts in the Enantioselective Propargylation of Aldehydes with Allenyltrichlorosilane
作者:Jinshui Chen、Burjor Captain、Norito Takenaka
DOI:10.1021/ol200102c
日期:2011.4.1
A highly enantioselective synthesis of homopropargylic alcohols is achieved by using the new helical chiral 2,2'-bipyridine N-monoxide catalyst and allenyltrichlorosilane. This method can be further extended to the enantio- and regioselective propargylation of N-acylhydrazones.