Iron(III)-Catalyzed Addition of Benzylic Alcohols to Aryl Alkynes - A New Synthesis of Substituted Aryl Ketones

A new, efficient and direct addition of benzylic alcohols with terminal aryl alkynes was developed with the inexpensive, non-toxic, FeCl3 catalyst in nitromethane. The reaction provides a simple method for the synthesis of substituted aryl ketones under mild conditions, and the reaction is highly atom-economical. Several substituted terminal alkynes underwent smooth reaction with various substituted benzylic alcohols. The electron-rich alkynes reacted more efficiently and gave higher yields than did the neutral or electron-deficient alkynes. A wide range of functional groups were tolerated in the developed protocol. The intermediate of this reaction was isolated, and a possible mechanism has been proposed. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)