Visible-Light-Promoted Site-Selective <i>N</i>¹-Alkylation of Benzotriazoles with α-Diazoacetates

Abstract

A visible-light-promoted highly site-selective <i>N</i>¹-alkylation of benzotriazoles with diazo compounds has been achieved under mild and metal-free conditions. Using cheap, readily available <i>p</i>-benzoquinone (PBQ) as a catalyst, a wide range of benzotriazoles and diazo compounds are reacted, providing <i>N</i>¹-alkylated benzotriazoles in moderate to excellent yields with excellent <i>N</i>¹-selectivities. Preliminary mechanistic studies suggest that a radical process accounts for the exclusive site-selectivity of this transformation.