Comparative investigation of the regioselectivity in styrene and alpha-methylstyrene hydroalkoxycarbonylation as a function of palladium catalyst structure
C. Benedek et al., Comparative investigation of the regioselectivity in styrene and alpha-methylstyrene hydroalkoxycarbonylation as a function of palladium catalyst structure, J ORGMET CH, 586(1), 1999, pp. 85-93
Catalytic pathways of the styrene and m-methyl-styrene hydroalkoxycarbonyla
tion in the presence of Pd(PPh3)(2)Cl-2 and Pd(PPh3)(2)Cl-2/SnCl2 catalyst
precursors have been suggested. As a method, deuterium labelling with EtOD
has been applied and it resulted in mixtures of mono- and polydeuterated re
action products, detected and determined by NMR methods. Comparative elucid
ation of the mechanisms governing these systems does support the assumption
that the hydride route is operative. The different behaviour of the metal-
alkyl intermediates accounts for the observed strong influence of catalyst
and substrate structure on regioselectivity. (C) 1999 Elsevier Science S.A.
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