Synergistic Activation of Nitrite and Thiocarbonyl Compounds Affords NO and Sulfane Sulfur via (Per)thionitrite (SNO⁻/SSNO⁻)

Abstract

(Per)thionitrite (SNO–/SSNO–) intermediates play vital roles in modulating nitric oxide (NO) and hydrogen sulfide (H2S) dependent bio‐signalling processes. Whilst the previous preparations of such intermediates involved reactive H2S/HS– or sulfane sulfur (S0) species, the present report reveals that relatively stable thiocarbonyl compounds (such as carbon disulfide (CS2), thiocarbamate, thioacetic acid, and thioacetate) react with nitrite anion to yield SNO–/SSNO–. For instance, the reaction of CS2 and nitrite anion (NO2‐) under ambient condition affords CO2 and SNO–/SSNO–. A detailed investigation involving UV‐vis, FTIR, HRMS, and multinuclear NMR studies confirm the formation of SNO–/SSNO–, which are proposed to form through an initial nucleophilic attack by nitrite anion followed by a transnitrosation step. Notably, reactions of CS2 and nitrite in the presence of thiol RSH show the formation of organic polysulfides R‐Sn‐R, thereby illustrating that the thiocarbonyls are capable of influencing the pool of bioavailable sulfane sulfurs. Furthermore, the availability of both NO2‐ and thiocarbonyl motifs in the biological context hints at their synergistic metal‐free activations leading to the generation of NO gas and various reactive sulfur species through SNO–/SSNO–.

Chalcogen bonding interaction between ebselen and nitrite promote N-nitrosation of amines

“…While the interactions of EbSe with various ROS (such as peroxides, peroxynitrite, and hydroxyl radical) were previously assessed computationally, 4–6,11 the reactivity of nitrite anion ( ONO − ) with ebselen ( EbSe )/ebsulfur ( EbS ) is not known to the best of our knowledge. Inspired by our recent work on the generation of reactive intermediates from the reaction of nitrite anion and organosulfur compounds, 13 the objective of this work is to probe the interactions/reactions between EbSe/EbS and ONO − using in-depth NMR spectroscopic and computational analyses. This work reveals that the noncovalent interactions in the resultant adduct complex EbSe⋯ONO − amplify the reactivity of the otherwise stable nitrite anion towards aromatic amines (Fig.…”