Recyclable and reusable Pd(OAc)2/P(1-Nap)3/[bmim][PF6]/H2O system for the addition of arylboronic acids to aldehydes

Abstract

A stable and efficient Pd(OAc)2/P(1-Nap)3[tri(1-naphthyl)phosphine] catalytic system for the addition of arylboronic acids to aldehydes has been developed. In the presence of Pd(OAc)2 and P(1-Nap)3, the addition reaction of arylboronic acids with aldehydes was carried out smoothly at 65 °C to give a variety of carbinol derivatives in good to excellent yields using a mixture of [bmim][PF6] and water as the solvent. The isolation of the products was readily performed by the extraction with diethyl ether, and the Pd(OAc)2/P(1-Nap)3/[bmim][PF6]/H2O system could be easily recycled and reused six times without significant loss of catalytic activity. Our system not only avoids the use of easily volatile THF or toluene as solvent but also solves the basic problem of palladium catalyst and these phosphine ligand reuse.