Formation of alcohols from the reactions of buta-1,3-diene and isoprene with aldehydes catalysed by nickel complexes

Abstract

The reaction of buta-1,3-diene with acetaldehyde, benzaldehyde, and acrolein in the presence of bis(1,5-cyclooctadiene)nickel and an organophosphorus ligand has been demonstrated to yield 2 : 1 adducts. With triphenylphosphine as ligand high selectivity to 1-substituted-3,6,8-nonatrien-1-ols was found. A similar reaction between isoprene and acetaldehyde in the presence of (cyclododecatriene) nickel and triphenylphosphine gave mainly 2 : 1 adducts in which the isoprene was dimerised in a head-tail manner. The major products were 3,7-dimethyl-3-vinylocta-7-en-2-ol and its isomer 3,7-dimethyl-3-vinylocta-6-en-2-ol. The selectivity of this reaction is discussed in terms of the σ,η character of the bis(η-allyl)nickel intermediate.