Alkylation of aromatic aldehydes with alkylboron chloride derivatives

The reaction of aryl aldehydes with alkylboron chlorides has been investiga ted. Monoalkylboron dichlorides react with aryl aldehydes in hexane under r eflux conditions to give a mixture of dichloroarylmethane and benzyl chlori de. Under the same reaction conditions, dialkylboron chlorides lead to form ation of a mixture of benzyl chloride and the chloroalkylation product. In the presence of a base such as 2,6-lutidine, the reactions of monoalkylboro n dichlorides with aryl aldehydes yield small amounts of the desired alkyla tion products at room temperature. Dialkylboron chlorides react with aryl a ldehydes in hexane in the presence of base to generate the corresponding ar ylalkylmethanols in good yields. (C) 2001 Elsevier Science Ltd. All rights reserved.