One-Pot Sequential Synthesis of 3,3′- or 2,3′-Bis(indolyl)methanes by Using 1,3-Dithiane as the Methylene Source

Abstract

A simple and efficient method for structurally diverse symmetrical and unsymmetrical 3,3′- and 2,3′-bisindolylmethanes has been developed through a one-pot sequential reaction using 1,3-dithiane as the methylene source. The important AhR agonists ICZ and malassezin were synthesized with excellent efficiency by this straightforward approach.

Divergent Synthesis of 3-Pyrrolidin-2-yl-1H-indoles, Symmetric and Unsymmetric Bis(Indolyl)Methanes (BIMs) through Photocatalyzed Decarboxylative Coupling/Friedel–Crafts Alkylation Reaction

“…Synthetic methods containing these motifs have therefore been widely studied. Nevertheless, the majority of synthetic methods available are for accessing symmetrical BIMs, whereas methods for accessing the unsymmetrical BIMs are more challenging. ,− The conditions developed were employed to obtain unsymmetrical BIMs 5 using 3.0 equiv of KHSO 4 as an acid additive from 3-pyrrolidin-2-yl-1 H -indole 3a and various indoles 2 . Next, the scope of substituted indoles was investigated (Scheme ).…”