Protodeboronation of arylboronic acids and triarylboroxines in Bu 20/THF

Abstract

The arylboron compounds Ph 3B 3N 3Me 3, Ar 3B 3O 3, or ArB(OH) 2 (Ar  Ph, p-BrC 6H 4, p-MeC 6H 4, m-NH 2C 6H 4 react with [Cr(CO) 6] in refluxing Bu 2O/THF (9:1) to afford the (η 6-arene) tricarbonyl-chromium(O) complexes of the protodeboronated substrates in yields of up to 55%. The proposed mechanism involves protodeboronation of the arylboron compound followed by complexation of the free arene by the chromium carbonyl moiety.