Synthesis of unsymmetrical sulfides catalyzed by n-tetrabutyl-ammonium tribromide: A selective fluorescence probe for mercury ion

A wide variety of unsymmetrical sulfides can be synthesized by trapping 2-naphthoquinone-1-methide intermediates, which are generated in situ from 2-naphthol and aromatic aldehydes, with thiols in presence of catalytic amount of n-tetrabutylammonium tribromide (TBATB). Mild reaction conditions, good yields and no dithioacetal formation as well as formation of brominated product are some of the salient features of the present protocol. Interestingly, the synthesized unsymmetrical sulfide 4aa can be used as selective fluorescence probe for mercury(II) ion.