Visible-Light-Induced Strain-Release [2π + 2σ] Cycloaddition of Bicyclo[1.1.0]butanes with N -Vinylamides: Access to Highly Functionalized Bicyclo[2.1.1]hexanes

The development of modular and efficient routes to functionalized bicyclo[2.1.1]hexanes (BCHs) is of considerable importance in synthetic and medicinal chemistry. Herein, we disclose a photocatalytic [2π + 2σ] cycloaddition between bicyclo[1.1.0]butanes (BCBs) and N-vinylamides that enables the direct and regioselective construction of 2-aminobicyclo[2.1.1]hexanes (2-aminoBCHs). Biological evaluation revealed that some of the BCH derivatives exhibit potent activity against A549 (lung cancer) and MDA-MB-231 (triple negative breast cancer) cell lines, outperforming their aromatic bioisosteres.