Transformations of N-substituted benzotriazoles into the corresponding carbanions by C-benzotriazole bond scissions

Various N-substituted benzotriazoles are transformed, by scission of the C-benzotriazole bond, into the corresponding carbanions by treatment with lithium. Thus, N-(diphenylmethyl)benzotriazole (1), N-benzylbenzotriazole (6), and N-allylbenzotriazole (10) all gave carbanions that reacted with diverse electrophiles to afford the corresponding products in good yields. This new methodology was successfully utilized to convert N-benzylbenzotriazole (6) and N-allylbenzotriazole (10) into dianion synthons by a sequential lithiation and reductive coupling and bis(benzotriazolyl)toluene (18) by double reductive couplings, demonstrating the synthetic potential of the present methodology.