3,5-Isoxazoles from alpha-bromo-pentafluorophenyl vinylsulfonates: synthesis of sulfonates and sulfonamides.

The regioselective 1,3-dipolar cycloaddition of alpha-bromo-pentafluorophenyl vinylsulfonate with nitrile oxides has been used to rapidly access a range of 3,5-isoxazoles which could be converted directly to their corresponding sulfonamides.

Trichlorophenol (TCP) sulfonate esters: a selective alternative to pentafluorophenol (PFP) esters and sulfonyl chlorides for the preparation of sulfonamides.

2,4,6-Trichlorophenol (TCP) sulfonate esters undergo effective aminolysis under conventional heating and microwave irradiation; the reactivity of these species is such that chemoselective transformations of PFP sulfonate esters can be achieved.