Enantioselective cycloisomerization of 1,6-enynes to bicyclo[3.1.0]hexanes catalyzed by rhodium and benzoic acid

Koji Masutomi; Keiichi Noguchi; Ken Tanaka

doi:10.1021/ja504048u

Enantioselective cycloisomerization of 1,6-enynes to bicyclo[3.1.0]hexanes catalyzed by rhodium and benzoic acid

J Am Chem Soc. 2014 May 28;136(21):7627-30. doi: 10.1021/ja504048u. Epub 2014 May 16.

Authors

Koji Masutomi¹, Keiichi Noguchi, Ken Tanaka

Affiliation

¹ Department of Applied Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology , Ookayama, Meguro-ku, Tokyo 152-8550, Japan.

PMID: 24823870
DOI: 10.1021/ja504048u

Abstract

It has been established that a cationic Rh(I)/(S)-Segphos or (S)-DTBM-Segphos complex and benzoic acid catalyze the enantioselective cycloisomerization of 1,6-enynes, possessing carbonyl groups at the enyne linkage, to 2-alkylidenebicyclo[3.1.0]hexanes. The present cycloisomerization may involve site selective γ-hydrogen elimination. The one-pot enantioselective cycloisomerization and lactonization of 1,6-enynes, leading to bicyclic lactones, has also been accomplished.