Key Role of Oxygen and Base in Catalytic Thioetherification: Access to Sulpur bridged Poly-Aromatic Hydrocarbons

Abstract

A green and sustainable high-yield method for the C-S coupling of a variety of bromoanthracenes with different thiols at ambient temperature in air has been formulated under metal-free conditions to yield a range of thiophenyl anthracenes. Mechanistic studies point to the fact that the base and molecular oxygen were found to operate in a synergistic fashion while accomplishing these thio-etherification reactions. High-resolution mass spectrometry studies have been instrumental in providing pivotal evidence for the involvement of sodium benzenethiolate, and phenyl thiyl radical. While the phenyl thiyl radical has been detected by trapping it with 2,2,6,6-tetramethylpiperidine-1-oxyl, the evolved hydrogen peroxide has been detected by redox titration. The considered 9,10-bis(phenylthio)anthracenes were found to possess exciting photo-physical properties