Silver catalyzed zinc Barbier reaction of benzylic halides in water

Benzylic chlorides react in aqueous dibasic potassium phosphate under silve r catalysis with aromatic aldehydes in the presence of zinc dust to give 1, 2-diaryl alcohols in moderate to good yields. Dimerization to bibenzyls and reduction of the halide are important side reactions. A wide range of subs tituted aromatic and heteroaromatic aldehydes and of substituted benzylic c hlorides can be used. Aliphatic aldehydes and ketones are unreactive. A mec hanism of two SET on the metal surface is discussed. (C) 1998 Elsevier Scie nce Ltd. All rights reserved.