Catalyst‐ and Metal‐Free Photo‐Oxidative Coupling of Thiols with BrCCl₃

Abstract

This paper reported a catalyst‐ and metal‐free method to construct disulfide bond with BrCCl3 under light irradiation. This clean and mild reaction promoted the oxidative coupling of thiols with wide substrate scope, and is applicable to benzylic, aryl and aliphatic thiols, especially cysteine derivative. The disulfides were obtained in high yields up to 98 %, avoiding the use of heating, strong oxidant, metal reagent or catalyst. This facile strategy will facilitate the synthesis of disulfide compounds.

Photooxidative Coupling of Thiols Promoted by Bromo(trichloro)methane in a Basic Aqueous Medium

“…22 We recently developed a metal- and catalyst-free photo-oxidative coupling of thiols in the presence of BrCCl 3 (3 equiv) and tetrahydrofuran (THF) as reagent and solvent, respectively (Scheme 1 D). 23 We found BrCCl 3 is readily photolyzed to generate radicals that initiate the process. We therefore hypothesized that a catalytic amount of BrCCl 3 might promote the reaction.…”

Triphenylamine-Based Ordered Mesoporous Polymer as a Metal-Free Photocatalyst for Oxidation of Thiols to Disulfide

“…88～89 ℃ (lit. [27] 88.2～ 89.5 ℃); 1 H NMR (400 MHz, CDCl 3 ) δ: 7.50 (ddd, J＝ 8.0, 2.7, 1.5 Hz, 4H), 7.24 (td, J＝7.7, 1.3 Hz, 2H), 7.05 (td, J＝7.6, 1.5 Hz, 2H); 13 C NMR (101 MHz, CDCl 3 ) δ: 136. 3, 133.1, 128.4, 128.1, 127.1, 121.2. 双(3-溴苯基)二硫醚(2k) [27] : 加入 1k (37.8 mg, 0.2 mmol, 1.0 equiv.…”

Facile and efficient transformation of thiols to disulfides via a radical pathway with N-anomeric amide

“… 10 Oxidative coupling of thiols as a direct method avoids the pre-activation of thiols, which was promoted by strong oxidants or oxidants assisted with various catalysts. 11 In order to use mild conditions, catalytic oxidation was explored by adopting various metal-based catalysts 12 or heterogeneous catalysts, 13 on the other hand, photochemistry 14 and electrochemistry 15 recently have drawn extensive attention. However, these methods suffer from some serious drawbacks such as over-oxidation, very high or low reaction temperatures, use of strong basic or acidic media and tedious work-up procedures.…”