Synfacts 2007(3): 0297-0297  
DOI: 10.1055/s-2007-968278
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Linear Esters Synthesis via Pd(II)-Borate-Catalyzed Hydroesterification

Contributor(s): Mark Lautens, Frédéric Ménard
T. O. Vieira, M. J. Green, H. Alper*
University of Ottawa, Canada and Sasol Technology, Sasolburg, South Africa
Further Information

Publication History

Publication Date:
20 February 2007 (online)

Significance

The borosalicylic acid 10 (BSA) generated in situ from salicylic acid and B(OH)3 is the acid promoter for this variant of the Reppe carbonylation. However, the regioselectivity is opposite to that typically observed and the linear ester 2 is formed preferentially to the branched one (3). Moreover, in the case of styrene substrates 1, the lowest regioselectivity observed (85%) was actually equal to the highest previously reported (M. A. Klingshirn et al. J. Organomet. Chem. 2005, 690, 3620-3626). The reaction failed in the case of N-heterocyclic systems like imidazoles and pyridines.