Cross-Coupling of Alkynes Catalyzed by Phebox−Rhodium Acetate Complexes

Jun-ichi Ito, Megumi Kitase, and Hisao Nishiyama*
Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan
Organometallics, 2007, 26 (25), pp 6412–6417
DOI: 10.1021/om700742t
Publication Date (Web): November 1, 2007
Copyright © 2007 American Chemical Society
*

 To whom correspondence should be addressed. E-mail:  hnishi@ apchem.nagoya-u.ac.jp.

Abstract

Abstract Image

Cross-coupling between terminal alkynes and dimethyl acetylenedicarboxylate (3) in the presence of 1 mol % bis(oxazolinyl)phenyl−rhodium acetate complex, (Phebox-R)Rh(OAc)2(H2O) (1-ip, R = iPr), under 1 atm hydrogen atmosphere furnished alkynyl-substituted maleic acid dimethyl esters with high Z-selectivity. Rh−acetylide complexes (Phebox-R)Rh(OAc)(−CCPh) (5-ip, R = iPr; 5-dm, R = Me2) were isolated on the reactions of 1-ip and 1-dm with phenylacetylene. Reactions of 5-ip and 5-dm with 3 provide the corresponding vinyl complexes (Phebox-R)Rh(OAc)(−C(CO2Me)C(CO2Me)CCPh) (6-ip, R = iPr; 6-dm, R = Me2) with E-configuration. Further reaction of 6-ip with phenylacetylene resulted in the formation of an enyene 4a accompanied by the formation of 5-ip. The molecular structures of 5-dm and 6-dm were determined by X-ray diffraction.

View: Full Text HTML | Hi-Res PDF

Tools

History

  • Published In Issue December 03, 2007
  • Received July 23, 2007

Recommend & Share

Related Content

Other ACS content by these authors: