Catalytic Diastereo- and Enantioselective Vinylogous Mannich Reaction of Alkylidenepyrazolones to Isatin-Derived Ketimines

Org Lett. 2021 Oct 1;23(19):7391-7395. doi: 10.1021/acs.orglett.1c02571. Epub 2021 Sep 23.

Abstract

A valuable organocatalytic vinylogous Mannich reaction between alkylidenepyrazolones and isatin-derived ketimines has been successfully established. Squaramide organocatalyst, prepared from quinine, catalyzed the diastereo- and enantioselective vinylogous Mannich addition, affording a range of aminooxindole-pyrazolone adducts (24 examples) with excellent outcomes: up to 98% yield with complete diastereoselectivity and excellent enantioselectivity (up to 99% ee). Additionally, different synthetic transformations were performed with the chiral pyrazolone-oxindole adducts.

Publication types

  • Research Support, Non-U.S. Gov't