Modular Counter-Fischer-Indole Synthesis through Radical-Enolate Coupling

Y A single-electron transfer mediated modular indole formation reaction from a 2-iodoaniline derivative and a ketone has been developed. This transition-metal-free reaction shows a broad substrate scope and unconventional regioselectivity trends. Moreover, important functional groups for further transformation are tolerated under the reaction conditions. Density functional theory studies reveal that the reaction proceeds by metal coordination, which converts a disfavored 5-endo-trig cyclization to an accessible 7-endo-trig process.

Automated summary

A modular indole formation reaction using single-electron transfer from a 2-iodoaniline derivative and a ketone has been developed, showing broad substrate scope and unconventional regioselectivity trends. Metal coordination is found to convert a disfavored 5-endo-trig cyclization to an accessible 7-endo-trig process in this transition-metal-free reaction.