Enantioselective Reductive Coupling of 1,3-Enynes to Glyoxalates Mediated by Hydrogen: Asymmetric Synthesis of β,γ-Unsaturated α-Hydroxy Esters
作者:Young-Taek Hong、Chang-Woo Cho、Eduardas Skucas、Michael J. Krische
DOI:10.1021/ol7015548
日期:2007.9.1
Catalytic hydrogenation of 1,3-enynes 1a-8a in the presence of ethyl glyoxalate at ambient pressure and temperature using a rhodium catalyst modified by (R)-(3,5-tBu-4-MeOPh)-MeO-BIPHEP results in highly regio- and enantioselective reductivecoupling to furnish the corresponding alpha-hydroxy esters 1b-8b. As demonstrated by the elaboration of alpha-hydroxy ester 1b, the terminal and internal olefin