Light-Induced Reactivity of Nucleophilic Siloxycarbene with Heterocumulenes: Synthesis of α-Ketoamides, Hydantoins, Oxoacetamidines, and Amides

We report the reactivity of in situ-generated nucleophilic siloxycarbenes from acylsilanes via the 1,2-Brook rearrangement in the presence of visible light with heterocumulenes. This method significantly advances from the conventional use of electrophilic carbenes stabilized by metal catalysts and harsh reaction conditions. The reactivity was explored with isocyanates, carbodiimides, and <i>N</i>-sulfinylamines to synthesize α-ketoamides, hydantoins, oxoacetamidines, and amides. In addition, this work demonstrated the synthetic utility and synthesis of biologically active molecules. Moreover, mechanistic insights reveal that this reaction proceeds through a singlet carbene mechanism.