UV-Light-Induced N-Acylation of Amines with α-Diketones

Herein, we develop a mild method for N-acylation of primary and secondary amines with alpha-diketones induced by ultraviolet (UV) light. Forty-six examples with various functional groups are explored at room temperature with irradiation by three 26 W UV lamps (350-380 nm). The yield reaches 97%. The gram scale experiment product yield is 76%. Moreover, this system can be applied to the synthesis of several amino acid derivatives. Mechanistic studies show that benzoin is generated in situ from benzil under UV irradiation.

Automated summary

A mild method for N-acylation of primary and secondary amines with alpha-diketones induced by ultraviolet (UV) light was developed in this study. The system showed high yields of products with various functional groups at room temperature. Mechanistic studies revealed the in-situ generation of benzoin from benzil under UV irradiation.