Visible-light-induced copper-catalyzed oxidative esterification of α-azidoketones with diazoacetates: access to α-acyloxyacetates

Abstract

A copper(II)-catalyzed 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-mediated synthesis of α-acyloxyacetates from α-azidoketones and diazoacetates under visible light at room temperature is described. This reaction involves an oxidative esterification process, leading to the formation of two new C–O bonds with the elimination of dinitrogen molecules in the overall process. 20 examples of α-acyloxyacetates were synthesized in high yields (70–86%) by coupling various α-azidoketones with diazoacetates. α-Azidoketones containing electron-donating groups (Me, MeO), electron-withdrawing groups (CN, NO₂), halogen atoms (Cl, Br), and other aryl groups are compatible with various substituted diazoacetates (ethyl, tertiary butyl, benzyl), resulting in the formation of α-acyloxyacetates.