Gold(I)-catalysed dehydrative formation of ethers from benzylic alcohols and phenols

Abstract

We report the cross-dehydrative reaction of two alcohols to form unsymmetrical ethers using NHC-gold(I) complexes (NHC = N-heterocylic carbene). The optimised methodology proceeds under mild reaction conditions and produces water as the sole by-product. The synthetic utility of this environmentally benign methodology is exemplified by forming a range of ethers from readily available phenols bearing electron-withdrawing substituents and secondary benzylic alcohols with various substituents. Finally, the chemoselectivity obtained in these reactions is explained.