A study on the catalytic pathways of the hydroalkoxycarbonylation reactionof styrene

The catalytic pathways of the Pd(PPh3)(2)Cl-2/SnCl2-catalysed styrene hydro alkoxycarbonylation reaction have been elucidated. Using deuterium labellin g, the different reaction products were detected by mass spectral analysis and the deuterium content and its distribution determined by H-1-,H-2- and C-13-NMR methods. The great number of labelled species supports the assumpt ion that the hydride (Pd-H) route is the operating mechanism of this system . Alkyl-metal intermediates easily undergo beta-hydride elimination. This p rocess is reversible for both isomers even at low reaction temperature (C) 1999 Elsevier Science S.A. All rights reserved.