Photocatalytic oxidative cyclopropanation of aza-1,6-enynes: construction of 3-aza-bicyclo[3.1.0]hexane derivatives

An operationally simple, photocatalytic, and unprecedentedly metal-free approach for synthesizing 3-aza-bicyclo[3.1.0]hexane from aza-1,6-eynes has been developed. This method allows the synthesis of highly decorated aza-bicyclo[3.1.0]hexanes under mild reaction conditions with excellent functional group tolerance and a broad substrate scope. The proposed radical pathway for the reaction is well supported by the control experiments. The advantages of the reaction include its operational simplicity and atom economy, in addition to its broad substrate scope, and not requiring a metal catalyst.