Synthesis of evodiamine and its derivatives through a visible-light-driven intramolecular C[sbnd]N[sbnd]cross-coupling reaction

Abstract

A visible-light-initiated CNcross-coupling reaction is described, featuring metal-free and photocatalyst-free, at ambient temperature, with air as the oxidant and pinacolborane as the reducing agent. The substrates with electron-withdrawing groups give higher yields than those with electron-donating groups, but the substituent position has a negligible influence on yields. Moreover, DFT calculations were conducted and the results matched the free radical reaction mechanism. The reaction provides a straightforward and environment-friendly approach for the synthesis of evodiamine and its derivatives.