Palladium-Catalyzed Carbonylative Cyclization of Unsaturated Aryl Iodides and Dienyl Triflates, Iodides, and Bromides to Indanones and 2-Cyclopentenones

Steve V. Gagnier and Richard C. Larock*
Contribution from the Department of Chemistry, Iowa State University, Ames, Iowa 50010
J. Am. Chem. Soc., 2003, 125 (16), pp 4804–4807
DOI: 10.1021/ja0212009
Publication Date (Web): March 29, 2003
Copyright © 2003 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.

, larock@iastate.edu

Abstract

Abstract Image

Indanones and 2-cyclopentenones have been successfully prepared in good to excellent yields by the palladium-catalyzed carbonylative cyclization of unsaturated aryl iodides and dienyl triflates, iodides, and bromides, respectively. The best results are obtained by employing 10 mol % of Pd(OAc)2, 2 equiv of pyridine, 1 equiv of n-Bu4NCl, 1 atm of CO, a reaction temperature of 100 °C, and DMF as the solvent. This carbonylative cyclization is particularly effective on substrates that contain a terminal olefin. The proposed mechanism for this annulation includes (1) Pd(OAc)2 reduction to the active palladium(0) catalyst, (2) oxidative addition of the organic halide or triflate to Pd(0), (3) coordination and insertion of carbon monoxide to produce an acylpalladium intermediate, (4) acylpalladation of the neighboring carbon−carbon double bond, (5) reversible palladium β-hydride elimination and re-addition to form a palladium enolate, and (6) protonation by H2O to produce the indanone or 2-cyclopentenone.

View: Full Text HTML | Hi-Res PDF

Tools

History

  • Published In Issue April 23, 2003
  • Received September 23, 2002

Recommend & Share

Related Content

Other ACS content by these authors: