Simple and efficient TiCl4-mediated synthesis of biaryls via arylmagnesium compounds

Oxidative self-coupling reactions of various arylmagnesium bromides with TiCl4 affords the corresponding symmetric biaryls in moderate to good yields at 0 degreesC or lower. Tributylmagnesate-induced halogen-magnesium exchange of aryl halides followed by the coupling reaction provides biarlys in good yields under mild conditions. This method can achieve a one-pot synthesis of biaryls containing functional groups such as esters, amides, or nitriles. (C) 2000 Elsevier Science Ltd. All rights reserved.