<i>N</i>,<i>N</i>,<i>N</i>’,<i>N</i>’-Tetramethylethylenediamine-Enabled Photoredox-Catalyzed C–H Methylation of <i>N</i>-Heteroarenes

Abstract

Aiming at the valuable methylation process, readily available and inexpensive N,N,N′,N′-tetramethylethylenediamine (TMEDA) was first identified as a new methyl source in photoredox-catalyzed transformation in this work. By virtue of this simple methylating reagent, a facile and practical protocol for the direct C–H methylation of N-heteroarenes was developed, featuring mild reaction conditions, broad substrate scope, and scalability. Mechanistic studies disclosed that a sequential photoredox, base-assisted proton shift, fragmentation, and tautomerization process was essentially involved.

Topics & Concepts