CpMn(CO)₃-Catalyzed Photoconversion of Thiols into Disulfides and Dihydrogen

Abstract

The UV photolysis of CpMn(CO)3 with thiols at room temperature effected the following catalytic transformation: 2 RSH → R2S2 + H2. This reaction is a cleaner and greener way toward making disulfides, as it produces dihydrogen as the only side-product. The manganese system exhibits high chemoselectivity as the transformation proceeds efficiently even in the presence of numerous functional groups. A manganese dicarbonyl complex, CpMn(CO)2RSH, and cyclopentadiene have also been detected using FTIR and NMR spectroscopic techniques, respectively. Based on our experimental data, a mechanism has been proposed to account for the catalysis.

Photocatalytic Transformation of Organic and Water-Soluble Thiols into Disulfides and Hydrogen under Aerobic Conditions Using Mn(CO)5Br

“…We have recently reported on the suitability of CpMn(CO) 3 as a precursor for a greener catalytic system: the conversion of thiols into disulfides with hydrogen as the only other product. 22 Although conditions for the transformation can be considered mild, the catalysis proceeds only in the absence of oxygen.…”

Electrocatalytic proton reduction catalyzed by a dimanganese disulfide carbonyl complex containing a redox-active internal disulfide bond

“…Our group has shown that thiols could be transformed into disulfides and H 2 using Mn(CO) 5 Br or CpMn(CO) 3 under UV-visible light. 9,10 Since enzymes such as glutathione reductase and cysteine reductase can easily reduce the respective disulfides into thiols using proton sources, combining the features of the manganese complexes and the enzymes into one may convert H + into H 2 without sacrificing thiols in the process through the reversible dissociation and formation of the S-S and S-H bonds.…”

Aerobic oxidation of thiols to disulfides under ball-milling in the absence of any catalyst, solvent, or base

“…(2-(4-Hydroxyphenyl)disulfanyl)phenol18 (Table 2, entry 7).1 H NMR (500 MHz, CDCl 3 ) d 5.44 (s, 2H), 6.76 (d, J = 8.5 Hz, 4H), 7.34 (d, J = 8.5 Hz, 4H); 13 C NMR (125 MHz, CDCl 3 ) d 116.3 (4C), 128.6 (2C), 133.0 (4C), 156.2 (2C).2-(2-(2-Aminophenyl)disulfanyl)benzenamine 12b (Table2, entry 8). 1 H NMR (500 MHz, CDCl 3 ) d 4.22 (s, 4H), 6.59 (t, J = 7 Hz, 2H),6.71 (d, J = 8 Hz, 2H), 7.15 (t, J = 7 Hz, 4H); 13 C NMR (125 MHz, CDCl 3 ) d 115.3 (2C), 118.3 (2C), 118.8 (2C), 131.7 (2C), 136.9 (2C), 148.7 (2C).…”