Bridged Bicyclic Building Block Upgrading: Photochemical Synthesis of bicyclo[3.1.1]heptan-1-Amines

Compounds containing bridged bicyclic carbon skeletons are desirable building blocks for medicinal chemistry. However, as a result of their inefficient, linear syntheses, commercially available compounds of this sort are plagued by high costs and/or a lack of diversity in substitution patterns. Herein we report the conversion of the readily available bicyclo[1.1.1]pentan-1-amine substructure to a wide range of poly-substituted bicyclo[3.1.1]pentan-1-amines using imine photochemistry. 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, sp³-rich primary amine building blocks.