Direct Access to the Simplest N -Substituted Pyrroles from Furans Enabled by Tailored Photocatalysts

Abstract

N-Methylpyrroles are important motifs in pharmaceuticals and biologically relevant compounds, yet their synthesis commonly relies on direct N-methylation of N–H pyrroles, a process often limited by the instability of pyrrole and the use of toxic alkylating reagents under harsh conditions. Herein, we report a photocatalytic strategy for the direct conversion of readily available furans to N-methylpyrroles. The reaction efficiency was markedly improved compared to the first-generation catalytic protocol through the development of tailored photocatalysts. Combining skeletal editing with continuous-flow photochemistry, this method provides efficient access to N-methylpyrroles under mild conditions while avoiding preformed N–H pyrrole substrates and conventional methylating agents. The utility of the protocol was further demonstrated through the late-stage diversification of structurally complex molecules.