The difference in catalytic activity for indium and bismuth may well be due to the relative stability constants of their complexes with the sulfamoylating agent (chloride or triflate) and the product sulfonamide. Interestingly, lowering the catalytic loading of In(OTf) 3 to 10 mol% affords 60% yield and 5 mol% of catalyst affords 30% yield of product. This suggests that it takes six molecules of product to poison each indium atom. Indeed, if six equivalents of the product (relative to ...
