Visible-light-induced cyclization of cyclic N -sulfonyl ketimines to N -sulfonamide fused imidazolidines.

A visible-light-induced metal-free cascade cyclization of cyclic N -sulfonyl ketimines with N -arylglycines for the construction of N -sulfonamide-fused imidazolidines was developed. The procedure employed 3 mol% of eosin Y as the photocatalyst at room temperature under visible light irradiation, providing various N -sulfonamide-fused imidazolidines in good yields (32 examples, up to 86% yields).