[3+2] Cycloaddition between 3‐Isothiocyanato Oxindoles and Nitroso Compounds

Abstract

Catalyzed by 10 mol‐% PhCO2H, the [3+2] cycloaddition between 3‐isothiocyanato oxindoles and nitroso compounds proceeded readily to deliver 1,2,4‐oxadiazolidine‐3‐thione‐fused spirooxindoles in 40–82 % yield. The structures of the title compounds were firmly confirmed by X‐ray single‐crystal structure analysis.