Silica Gel Mediated Friedel–Crafts Alkylation of 3‐Indolylmethanols with Indoles: Synthesis of Unsymmetrical Bis(3‐indolyl)methanes

An efficient and expedient approach for the synthesis of unsymmetrical bis(3‐indolyl)methanes by employing a silica gel mediated Friedel–Crafts alkylation of 3‐indolylmethanols with various indoles is described. The synthetic utility of this transformation was demonstrated by reusing the silica gel up to 10 times without any apparent loss of reactivity. Unsymmetrical bis(3‐indolyl)methanes were synthesized from readily available 3‐indolylmethanols and indoles in a reaction that was mediated by silica gel under mild conditions. The silica gel was recovered and reused up to 10 times without an apparent loss of activity.