K+/Cu2+ Co-chelated diastereoselective Friedel–Crafts reaction with chiral N-sulfinyl ketimines for the facile synthesis of chiral bisindoles and their cytotoxicity

Abstract

A novel K⁺/Cu²⁺ co-chelated diastereoselective Friedel–Crafts reaction with chiral N-sulfinyl ketimines has been developed for the synthesis of chiral bisindoles. The method exhibits broad substrate compatibility and high stereoselectivity. The synthesized bisindoles show significant cytotoxicity against tumor cell lines such as MG63 and HepG2, with Compound 29 demonstrating selective inhibitory effects on osteosarcoma cells. This protocol provides a useful strategy for the efficient construction of chiral bisindoles. The potential of these compounds in cancer therapy was also highlighted.