Photocatalytic Regioselective and Stereoselective [2+2] Cycloaddition of Styrene Derivatives Using a Heterogeneous Organic Photocatalyst

Photocatalytic [2 + 2] cycloaddition is a useful tool for the synthesis of cyclobutane derivatives, which contributes a large part to natural compound production. Usually, the [2 + 2] cycloadditions are catalyzed by transition-metal complexes. Here, we report the use of a pure organic photocatalyst based on a conjugated microporous polymer network for the [2 + 2] cycloaddition of styrene derivatives under the irradiation of visible light. Both unsymmetrical and homocycloaddition could be obtained with high conversion and selectivity. In addition, natural products, such as di-O-methylendiandrin A and endiandrin A are also synthesized with a high catalytic efficiency.