Ring Opening of N-Sulfonyl Aziridines by Amines in Silica-Water

Ring opening reactions of N-sulfonyl aziridines by primary and secondary amines in silica gel(SG)-water system were achieved,which provided a mild,practical and environmentally benign method to synthesize mono-and bis-sulfonyl substituted amines.When primary and secondary amines were used in excess,they reacted with N-sulfonyl aziridines smoothly at room temperature,mainly affording 1∶1 ring opening products.Reactions of primary amines with 2 equiv.of aziridines produced 2∶1 ring opening products.Some 1∶1 products can be cyclized with CS2 to synthesize N-sulfonyl cyclothioureas also in water.