Electrocatalytic\nEnantioselective Tandem C–H\nIndolization toward Biindolyl Atropisomers: Reaction Development and\nMechanistic Insight

The\nelectrochemical methods for asymmetric indolization\nare still\nelusive and pose a significant challenge. Taking advantage of 2-alkynylanilines\nas electrochemically compatible indolyl equivalents, we herein represent\na mild and highly enantioselective electrocatalytic process for tandem\nC–H indolization to form 2,3′-biindolyl atropisomers\nalong with hydrogen evolution reaction. Integrated experimental and\ncomputational mechanistic studies revealed that a sequential C–H\nmetalation/nucleophilic cyclization/reductive elimination/anodic oxidation\nsequence involving a Rh<sup>III</sup>–Rh<sup>I</sup>–Rh<sup>III</sup> catalytic cycle accounts for the established transformation.