N-Heterocyclic Carbene Catalyzed [4+2] Annulation of Enals via a Double Vinylogous Michael Addition: Asymmetric Synthesis of 3,5-Diaryl Cyclohexenones

Xiang-Yu Chen; Qiang Liu; Pankaj Chauhan; Sun Li; Anssi Peuronen; Kari Rissanen; Ehsan Jafari; Dieter Enders

doi:10.1002/anie.201702881

N-Heterocyclic Carbene Catalyzed [4+2] Annulation of Enals via a Double Vinylogous Michael Addition: Asymmetric Synthesis of 3,5-Diaryl Cyclohexenones

Angew Chem Int Ed Engl. 2017 May 22;56(22):6241-6245. doi: 10.1002/anie.201702881. Epub 2017 Apr 21.

Authors

Xiang-Yu Chen¹, Qiang Liu¹, Pankaj Chauhan¹, Sun Li¹, Anssi Peuronen², Kari Rissanen², Ehsan Jafari¹, Dieter Enders¹

Affiliations

¹ Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany.
² Department of Chemistry, Nanoscience Center, University of Jyvaskyla, 40014, JYU, Finland.

PMID: 28429516
DOI: 10.1002/anie.201702881

Abstract

A strategy for the N-heterocyclic carbene (NHC) catalyzed asymmetric synthesis of 3,5-diaryl substituted cyclohexenones has been developed via oxidative [4+2] annulation of enals and alkenylisoxazoles. It is the first example of using NHC organocatalysis in a double vinylogous Michael type reaction, a challenging but highly desirable topic. This unprecedented protocol affords good yields as well as high to excellent diastereo- and enantioselectivities.

Keywords: Michael addition; N-heterocyclic carbenes; annulations; asymmetric synthesis; cyclohexenones.

Publication types

Research Support, Non-U.S. Gov't