F. Bouachir et al., CATIONIC ETA(3)-ALLYL COMPLEXES - 21 - TELOMERIZATION OF BUTA-1,3-DIENE WITH Z-H COMPOUNDS MEDIATED BY GROUP 10 COMPLEXES, Journal of organometallic chemistry, 569(1-2), 1998, pp. 203-215
Cationic (eta(3)-allyl) complexes of general formula [(eta(3)-allyl)M(
ligand)(2)]Y-+(-), where Y- is a non-coordinating anion (BF4-, ClO4-,
BF4-) have been examined in telomerization reactions of buta-1,3-diene
with representative nucleophiles. No reaction are observed for nickel
complexes, due to their high reactivity versus nucleophiles. With pal
ladium complexes, the reaction only occurs with alcohols and provides
an increased selectivity for telomers with more than two diene units,
leading to C-16, C-24 and even higher ethers. Although much less react
ive, platinum complexes can also produce higher telomers when hydrogen
osilanes are used. It is proposed, at least in the case of palladium,
that the formation of C-16 and C-24 ethers arises from the coupling of
C-8 units within dimeric palladium intermediates with the telogen act
ing as a bridging ligand. (C) 1998 Elsevier Science S.A. All rights re
served.