Asymmetric Synthesis of Protected Cyclohexenylamines and Cyclohexenols by Rhodium-Catalyzed [2+2+2] Cycloaddition

Koji Masutomi; Haruki Sugiyama; Hidehiro Uekusa; Yu Shibata; Ken Tanaka

doi:10.1002/anie.201608952

Asymmetric Synthesis of Protected Cyclohexenylamines and Cyclohexenols by Rhodium-Catalyzed [2+2+2] Cycloaddition

Angew Chem Int Ed Engl. 2016 Dec 5;55(49):15373-15376. doi: 10.1002/anie.201608952. Epub 2016 Nov 10.

Authors

Koji Masutomi¹, Haruki Sugiyama², Hidehiro Uekusa², Yu Shibata¹, Ken Tanaka¹

Affiliations

¹ Department of Chemical Science and Engineering, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo, 152-8550, Japan.
² Department of Chemistry, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo, 152-8551, Japan.

PMID: 27860088
DOI: 10.1002/anie.201608952

Abstract

It has been established that cationic rhodium(I)/axially chiral biaryl bis(phosphine) complexes catalyze the asymmetric [2+2+2] cycloaddition of 1,6-enynes with electron-rich functionalized alkenes, enamides, and vinyl carboxylates, to produce the corresponding protected cyclohexenylamines and cyclohexenols. Interestingly, regioselectivity depends on structures of substrates. The present cycloaddition was successfully applied to the enantioselective total synthesis of (-)-porosadienone by using the amide moiety as a leaving group.

Keywords: asymmetric catalysis; cycloadditions; enamides; reaction mechanisms; rhodium.

Publication types

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