Selective synthesis of octadienyl and butenyl ethers via reaction of 1,3-butadiene with alcohols catalyzed by homogeneous palladium complexes

Abstract

The selective synthesis, by telomerization of 1,3-butadiene with alcohols in the presence of palladium catalysts, both of octadienyl ethers (especially from higher linear primary alcohols) and of butenyl ethers is reported. The variation of the alcohol/diene molar ratio plays a decisive role in both the cases, excess of alcohol favouring in the former case the synthesis of octadienyl ethers with respect to octatrienes, being useful in the latter case, together with other factors such as high P/Pd and low Pd/diene molar ratios, to favour the formation of butenyl ethers. It has in fact been discovered that, for palladium catalysts, the formation of butenyl ethers is ruled by a complex mechanism involving both the reversible formation of butenyl ethers and their direct transformation into octadienyl ethers.