Phosphotungstic Acid Catalyzed Amidation of Alcohols

Mild nucleophilic substitution reactions of benzhydrylic, benzylic, allylic, and simple aliphatic alcohols with sulfonamides, benzamide, and 4-nitroaniline in the presence of 12-phosphotungstic acid as an efficient, eco-friendly, cheap, and air- and moisture-tolerant catalyst for the construction of CN bonds has been investigated. The amine derivatives were obtained in good yields (up to 98%). The reusable nature of the 12-phosphotungstic acid makes this protocol more attractive. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).