Phase-Transfer-Catalyzed, Enantioselective Vinylogous Conjugate Addition-Cyclization of Olefinic Azlactones To Access Multifunctionalized Chiral Cyclohexenones

Org Lett. 2019 May 3;21(9):3271-3275. doi: 10.1021/acs.orglett.9b01001. Epub 2019 Apr 18.

Abstract

An asymmetric, phase-transfer-catalyzed vinylogous conjugate addition-vinylogous cyclization cascade of olefinic azlactones with 4-nitro-5-styrylisoxazoles is reported. In the presence of an l- tert-leucine-derived urea-quaternary ammonium salt as a bifunctional phase-transfer catalyst and KF, two series of valuable optically pure cyclohexenones featuring two and three stereocenters were obtained in high yields with good to excellent enantio- and diastereoselectivities.

Publication types

  • Research Support, Non-U.S. Gov't