Highly Selective and Catalytic C-N Bond Cleavage of Tertiary Sulfonamides: Scope and Mechanistic Insight.

A highly chemoselective C-N bond cleavage reaction of -methoxybenzyl- (PMB), 3,4-dimethoxybenzyl- (DMB), or cinnamyl-substituted tertiary sulfonamides in the presence of catalytic Bi(OTf) is presented. A wide range of sulfonamide substrates smoothly furnished the corresponding C-N bond cleavage products in good to excellent yields. Great efforts have been made to obtain insights into the reaction mechanism based on a series of control experiments and mass spectroscopy.