Visible-light organophotoredox-mediated intermolecular formal [4+2] cycloadditions of arylcyclobutylamines with olefins

We have developed a visible-light-mediated formal [4 + 2] cycloaddition of arylcyclobutylamines with olefins, using QXPT-NPhCN as an organic photocatalyst. The corresponding cycloadducts could be obtained from electron-deficient olefins, aryl olefins and exocyclic olefins. We found that the addition of K3PO4 could significantly promote the cycloadditions. Using this method, 2-functionalized cyclohexylamines including the ones with spiro-skeletons can be expediently obtained. Based on the 3D-bioisostere principle, we designed and synthesized three cyclohexylamine 2-sulfonylurea compounds.

Automated summary

We have developed a visible-light-mediated formal [4 + 2] cycloaddition of arylcyclobutylamines with olefins, using QXPT-NPhCN as an organic photocatalyst. The corresponding cycloadducts could be obtained from electron-deficient olefins, aryl olefins, and exocyclic olefins. By adding K3PO4, the cycloadditions can be significantly promoted. This method allows the efficient synthesis of 2-functionalized cyclohexylamines, including those with spiro-skeletons.