Bicyclo[2.1.1]hexanes by Visible Light-Driven Intramolecular Crossed [2+2] Photocycloadditions

Bicyclo[2.2.1]hexanes have become increasingly popular building blocks in medicinal chemistry as bridged scaffolds that provide unexplored chemical space. We herein report a visible light-driven approach to these compounds that relies on an intramolecular crossed [2 + 2] photocycloaddition of styrene derivatives enabled by triplet energy transfer. Bicyclo[2.2.1]hexanes were obtained in good to high yields (19 examples, 61%-quantitative yield) and allowed for further functionalizations by consecutive reactions, thereby opening different pathways to decorate the aliphatic core structure.

Automated summary

This study presents a visible light-driven approach for the synthesis of Bicyclo[2.2.1]hexanes, and shows the possibility of further functionalization through consecutive reactions.