Kinetics of vinylation of 4′-bromoacetophenone with n-butyl acrylate using palladacycle catalyst

The kinetics of vinylation of 4 '-bromoacetophenone (4 '-BAP) with n-butyl acrylate (n-BA) has been studied using palladacycle catalyst precursor 1, in the presence of sodium acetate (NaOAc) as a base and tetrabutylammonium bromide (TBAB) as a promoter in N-methyl-2-pyrrolidinone (NMP) solvent. The rate was found to be first order with respect to 4 '-BAP, fractional order with the catalyst, and first order tending to zero order with NaOAc concentration. The rates passed through a maximum with variation of TBAB and n-butyl acrylate concentrations. The rate data have been analyzed to propose an empirical model, which is in good agreement with the mechanism already established for Heck reactions using palladacycle catalysts. (C) 2007 Elsevier B.V. All rights reserved.