Enantioselective Synthesis of 5-Trifluoromethyl-2-oxazolines under Dual Silver/Organocatalysis

J Org Chem. 2019 Jan 4;84(1):314-325. doi: 10.1021/acs.joc.8b02808. Epub 2018 Dec 21.

Abstract

The first enantioselective formal [3 + 2] cycloaddition between α-isocyanoesters and trifluoromethylketones to give 5-trifluoromethyl-2-oxazolines bearing two contiguous stereogenic centers, one of them being a quaternary stereocenter substituted with a CF3 group, has been developed. The reaction is based upon a multicatalytic approach that combines a bifunctional Brønsted base-squaramide organocatalyst and Ag+ as Lewis acid. The reaction could be achieved with a range of aryl and heteroaryl trifluoromethyl ketones, and the resulting oxazolines were obtained with good to excellent diastereo- and enantioselectivity.

Publication types

  • Research Support, Non-U.S. Gov't