Iodine-Triggered Aerobic Oxysulfonylation of Styrenes

An iodine-triggered dioxygen activation in oxysulfonylation reactions of unactivated olefins using sulfonyl hydrazides and iodine as catalyst is reported here. In one pot, near quantitative syntheses of beta-hydroxysulfones were achieved at 70 degrees C, within 7 h, in acetonitrile and under aerobic conditions. A plausible mechanism is established by radical trapping and O-18 labelling experiments for the operation-ally simple, efficient and economically viable transformation. The direct activation of aerial oxygen under metal-free and mild conditions is proposed for the oxysulfonylation of olefins.