NICKEL VS. PALLADIUM CATALYSTS FOR COUPLING REACTIONS OF ALLYL ALCOHOL WITH SOFT NUCLEOPHILES - ACTIVITIES AND DEACTIVATION PROCESSES

The performance of nickel-phosphine and palladium-phosphine catalytic systems for model coupling reactions of allyl alcohol (1) with soft nu cleophiles such as diethylamine (2), some active methylene compounds ( 4) or 1 itself in the formation of diallylether (7) are reported. It i s shown that for a number of reactions, particularly the amination of 1, nickel catalysts are much more active than comparable palladium sys tems. However, Ni-catalytic species are more sensitive than the corres ponding Pd ones, so that catalyst poisoning prevents some reactions to go to completion. The detection of allylbenzene (8) as a by-product i n the etherification and amination reactions of 1 together with a P-31 NMR study has allowed to highlight a degradation pathway involving th e cleavage of a phosphorus-carbon bond in a Ni-dppb intermediate. (C) 1998 Elsevier Science B.V. All rights reserved.