Palladium Complexes with N-Heterocyclic Carbene Ligands As Catalysts for the Alkoxycarbonylation of Olefins

Abstract

Palladium catalysts, generated from Pd(OAc) 2 and 2 equiv of N, N -dialkylbenzimidazolium iodide, are effective for the alkoxycarbonylation of olefins in high yields (>90%). Alkoxycarbonylation of 1-hexene in dimethylacetamide is achieved within 24 h at 110 °C using 1 mol % catalyst, 1000 psi CO, and ethanol. Reactions can be prepared in air, without the need of an acid additive to produce ethyl 2-methylhexanoate and ethyl heptanoate in approximately a 2:1 ratio.