Triarylmethyl Cation Catalysis: A Tunable Lewis Acid Organo­catalyst for the Synthesis of Bisindolylmethanes

Abstract

Triarylmethyl cations serve as tunable organocatalysts for the synthesis of bisindolylmethanes. The catalyst structure can be modified to increase or decrease reactivity as needed to match the requirements of the substrate. High yields are achieved for a variety of substrates by using these green catalysts. Catalyst tuning allows for the use of less reactive electrophiles by increasing the reactivity of the catalyst. Acid-sensitive products can be isolated under these mild reaction conditions.

Triarylmethyl Cation‐Catalyzed Three‐Component Coupling for the Synthesis of Unsymmetrical Bisindolylmethanes

“…Recently we reported that trityl cations are exceptional catalysts for the synthesis of bisindolylmethanes via aldehyde activation (Figure 1), and the tunability of these catalysts can be exploited to tailor the catalyst to less reactive substrates [4] . The products of this reaction are symmetrical bisindolylmethanes that incorporate two identical indole units.…”