Photochemical Formal (4+2)-Cycloaddition of Imine-Substituted Bicyclo[1.1.1]pentanes and Alkenes

Amines containing bridged bicyclic carbon skeletons are desirable building blocks for medicinal chemistry. Herein, we report the conversion of bicyclo[1.1.1]pentan-1-amines to a wide range of polysubstituted bicyclo[3.1.1]heptan-1-amines through a photochemical, formal (4 + 2)-cycloaddition of an intermediate imine diradical. To our knowledge, this is the first reported method to convert the bicyclo[1.1.1]pentane skeleton to the bicyclo[3.1.1]heptane skeleton. Hydrolysis of the imine products gives complex, sp(3)-rich primary amine building blocks.

Automated summary

In this study, a new method to convert bicyclo[1.1.1]pentan-1-amines to polysubstituted bicyclo[3.1.1]heptan-1-amines through a photochemical reaction of an intermediate imine diradical was reported. Hydrolysis of the imine products provides complex, sp(3)-rich primary amine building blocks. This is the first reported method to convert the bicyclo[1.1.1]pentane skeleton to the bicyclo[3.1.1]heptane skeleton.