One-pot Tandem Reactions for Direct Conversion of Thiols and Disulfides to Sulfonic Esters, Alcohols to Bis(indolyl)methanes and Synthesis of Pyrroles Catalyzed by N-Chloro Reagents

A convenient synthesis of sulfonic esters from thiols and disulfides has been described. In situ preparation of sulfonyl chlorides from thiols is accomplished by oxidation with Chloramin-T, tetra-butylammonium chloride (t-Bu4NCl) and water. The sulfonyl chlorides are then further allowed to react with phenol derivatives in the same reaction vessel. Also, a facile synthesis of bis(indolyl)methanes from alcohols using TCCA/KBr/wet-SiO2, and N-substituted pyrroles by reaction of hexane- 2,5-dione with primary amines has been accomplished under mild condition with excellent yields.