Visible light-mediated [1 + 2 + 2] cycloaddition reaction of nitroarenes and alkenes

We report a visible light-mediated [1 + 2 + 2] cycloaddition reaction between nitroarenes and alkenes, conducted under mild conditions, to synthesize isoxazolidines. This method operates without photocatalysts or transition metal catalysts. Mechanistic studies suggest that under light irradiation, the alkene interacts with the triplet state nitroarene to form a nitrone intermediate, acting as a C1 source. This intermediate undergoes a [3 + 2] cycloaddition with the alkene, resulting in the desired product.