Synthesis of 3‑Pyrrolin-2-ones by Rhodium-Catalyzed Transannulation of 1‑Sulfonyl-1,2,3-triazole with Ketene Silyl Acetal

α-Imino rhodium carbenoids generated from 1-sulfonyl 1,2,3-triazole were applied to the 3 + 2 cycloaddition with ketene silyl acetal, offering a novel and straightforward synthesis of biologically interesting compound 3-pyrrolin-2-one with broad substrate scope