Mechanistic insights into a copper–disulfide interaction in oxidation of imines by disulfides

Abstract

The concept of using disulfides as an oxidant for Cu(i) is introduced as part of a Cu-catalyzed process leading to the formation of benzothiazole from an iminodisulfide under an inert atmosphere.

Copper‐Catalyzed Activation of Disulfides as a Key Step in the Synthesis of Benzothiazole Moieties

“…The centerpiece of the method is the interaction between a disulfide moiety and a thiophilic metal – an interaction that enjoys growing attention in synthetic organic chemistry and biological chemistry alike 7. In our previous work, we examined the origin of the above chemistry in the Cu‐catalyzed intramolecular oxidation of imines by disulfides under anaerobic conditions 8. It was found that the substrate 1 smoothly transformed, under the above conditions, into the products 2 and 3 in 1:1 ratio, and, based on our experiments, corroborated by the gas‐phase data, a concise mechanism of the transformation was suggested, invloving the C–H bond activation as the rate‐limiting step (see Scheme ).…”

Copper‐catalyzed reactions: Research in the gas phase

“…This is often a problem in searching for copper (III) intermediates and more studies are necessary in this direction. Srogl et al have investigated copper catalyzed disproportionation of iminedisulfides (Scheme 17) from both synthetic and gas-phase perspectives (Srogl et al, 2009). For the ESI-MS studies the reactant 1 was mixed with a copper(I) catalyst and sprayed into the a mass spectrometer.…”

Gas‐phase studies of copper catalyzed aerobic cross coupling of thiol esters and arylboronic acids

“…the ionization process is believed to impose only a small energy to the species transferred to the gas phase, and therefore the gaseous ions often reflect the species contained in the sprayed solution). Moreover, ESI‐MS appears to be the most convenient method for a successful investigation of organometallic compounds in the gas phase and, in numerous cases, was successfully applied for studying organometallic reaction mechanisms …”

“…Moreover, ESI-MS appears to be the most convenient method for a successful investigation of organometallic compounds in the gas phase and, in numerous cases, was successfully applied for studying organometallic reaction mechanisms. [31][32][33][34][35][36][37][38][39][40][41][42] Reactions involving boronic acids play an important role as these acids are stable, commercially available reagents with relatively low toxicity. [43,44] Their application is most popular in Suzuki couplings, where palladium complexes are applied as catalysts.…”