Chemodivergent temperature-controlled switchable iron-catalysed annulation of o-vinylaniline with isatin derivatives

Abstract

Chemodivergent approaches strive to enable achieving regioselective and site-divergent transformations of multiple products from identical, readily accessible starting materials by changing the reaction parameters, but are challenging due to the complexity of precisely controlling the chemodiversity. Herein, we report a novel FeCl₃-catalyzed one-pot strategy involving switching the temperature to enable the selective synthesis of 5-methyl-7-phenyldibenzo[b,h][1,6] naphthy-ridin-6(5H)-one or 3-phenyl-1H-indole from o-vinylaniline and N-substituted isatin. Notably, the reaction exhibits temperature-controlled chemodivergence, selectively yielding either intramolecular or intermolecular products. This approach demonstrates a wide substrate scope, affording structurally diverse scaffolds under mild conditions. Furthermore, it provides an efficient route for synthesizing symmetrical urea derivatives and offers a potential pathway for directly synthesizing tryptanthrin and related bioactive molecules.