Waste-Free Swift Synthesis of Symmetrical and Unsymmetrical Diarylmethyl Thioethers from Diaryl Carbinols

Abstract

A waste-free and swift protocol to synthesize symmetrical and unsymmetrical diarylmethyl thioethers from diaryl carbinols and thiols in good to quantitative yields is reported. The thiol scope included alkyl and aryl thiols bearing electron-donating and electron-withdrawing groups. Short reaction time, high atom economy, inexpensive activator, free from workup and aryl halides, and gram-scale synthesis are the significant features of the new protocol.

Synthesis of diarylmethyl thioethersviaa DABCO-catalyzed 1,6-conjugate addition reaction ofp-quinone methides with organosulfur reagents

“…After that, various reaction systems ( e.g. , BF 3 ·OEt 2 (5 mol%), CH 2 Cl 2 , r.t.; 7 ZnCl 2 (10 mol%), DCM, r.t.; 8 TeaMs, 80 °C (microwave irradiation); 9 and HClO 4 –SiO 2 (5 mol%), r.t. 10 ) were developed to realize the direct conversion of diarylmethyl alcohols to diarylmethyl thioethers. However, the problem of using strong-smelling thiols must be solved, but some reaction systems are complex and have limited applications ( Scheme 1a ).…”