Cycloisomerization of Enynes via Rhodium Vinylidene-Mediated Catalysis

Hahn Kim and Chulbom Lee*
Department of Chemistry, Princeton University, Princeton, New Jersey 08544
J. Am. Chem. Soc., 2005, 127 (29), pp 10180–10181
DOI: 10.1021/ja052775j
Publication Date (Web): July 2, 2005
Copyright © 2005 American Chemical Society
*

In papers with more than one author, the asterisk indicates the name of the author to whom inquiries about the paper should be addressed.

, cblee@princeton.edu

Abstract

Abstract Image

A novel rhodium-catalyzed cycloisomerization has been developed which converts various acyclic enynes to their cyclic diene isomers with endoselectivity. Both [RhCl(COD)]2/P(4-FC6H4)3 and RhCl(PPh3)3 catalyst systems are effective in promoting the C−C bond-forming cyclization of enynes to furnish carbo- and heterocycles in good to excellent yield. Deuterium labeling studies suggest that the reaction proceeds through the formation of a rhodium vinylidene followed by subsequent [2 + 2] cycloaddition with the alkene and ring-opening of the resulting rhodacyclobutane. These mechanistic studies reevaluate a previously proposed reaction pathway and lead to the discovery of a new cycloisomerization reaction that involves migration of silyl and selenyl substituents at the alkyne of enyne substrates upon cyclization.

View: Full Text HTML | Hi-Res PDF

Tools

History

  • Published In Issue July 27, 2005
  • Received April 28, 2005

Recommend & Share

Related Content

Other ACS content by these authors: