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.