The first palladium-catalyzed 1,4-addition of terminal alkenes to acrylate esters

摘要

A novel and efficient procedure for the synthesis of δ,γ-alkenyl esters with complete E-stereochemistry by the 1,4-addition of alkenes to acrylate esters in the presence of a catalytic amount of palladium chloride has been developed. This method provides a rapid and efficient access to substituted δ,γ-alkenyl esters. The 1,4-addition of carbanions to α,β-unsaturated carbonyl compounds is one of the most attractive methods for constructing a new carbon-carbon bond in organic synthesis.Among them, a direct and reliable approach to a wide variety of γ,δ-alkynyl ketones and γ,δ-alkynyl esters is the 1,4-addition of terminal alkynes to unsaturated carbonyl compounds catalyzed by transition metals.In contrast, related transition metal-catalyzed 1,4-addition of alkenes to unsaturated carbonyl compounds is relatively rare because C(sp2)-H bonds of simple alkenes are less reactive toward transition metals than alkynes.