Fe-catalyzed efficient synthesis of 2,4- and 4-substituted quinolines via C(sp2)-C(sp2) bond scission of styrenes.

Abstract

Herein, we report a highly efficient, environmentally benign protocol for the domino synthesis of 2,4-disubstituted and 4-substituted quinoline molecules. The developed strategy involves an earth-abundant Fe-catalyzed C(sp²)-C(sp²) bond cleavage of styrene, followed by the hydroamination of the cleaved synthons with arylamines and subsequent C-H annulation to yield two valuable quinoline derivatives. Key features of this protocol include the use of O₂ as an ideal, green oxidant, operational simplicity and scalability, high atom- and step-economy, and cost-effectiveness, collectively enabling the single-step synthesis of two medicinally relevant N-heterocycles in excellent combined yields.