N-Heterocyclic Carbene and Chiral Brønsted Acid Cooperative Catalysis for a Highly Enantioselective [4+2] Annulation

Dedicated to Professor Dieter Enders, a pioneer in NHC catalysis, on the occasion of his 70^th birthday.

Abstract

A chiral NHC/Brønsted acid cooperative catalysis system has been developed for the asymmetric annulation of functionalized benzaldehydes and activated ketones, through dearomative generation of dienolate, to give 3-aryl-3-(perfluoroalkyl)isochroman-1-ones.

Key words

NHC - Brønsted acid - cooperative - annulation - isochromanone

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