Metal-free molecular iodine-catalyzed direct sulfonylation of pyrazolones with sodium sulfinates leading to sulfonated pyrazoles at room temperature

Abstract

A simple and convenient molecular iodine-catalyzed direct sulfonylation of pyrazolones with sodium sulfinates has been developed in the presence of TBHP at room temperature. This methodology can allow for the synthesis of a series of valuable sulfonated pyrazoles in good to excellent yields simply using readily-available starting materials without requiring any metal or cryogenics.