Direct annulation and alkylation of indoles with 2-aminobenzyl alcohols catalyzed by TFA

An efficient method for the annulation of indoles with 2-aminobenzyl alcohols, catalyzed by TFA, to furnish 5,6-fused indoline aminals is reported. This method can be extended to the alkylation of indoles at C3. 2-Aminobenzyl alcohols are used directly without recourse to protection of the aniline nitrogen or activation of the alcohol. (C) 2011 Elsevier Ltd. All rights reserved.