Vladimir A. Kokorekin

Facile Method for the Synthesis of Vicinal Azidoiodides by the Reaction of the NaN3–I2 System with Unsaturated Compounds

Abstract A facile and efficient method was developed for the synthesis of vicinal azidoiodides in 62–77% yields by the reaction of sodium azide and iodine with unsaturated compounds in methanol, aqueous methanol, or the water–methanol–tetrahydrofuran solvent system. The reaction in Et2O or CHCl3 produced only vicinal diiodides.

Oxidative transformation of N-substituted 3-aminopyrazoles to azopyrazoles using electrogenerated bromine as a mediator

The one-pot process of anodic transformation of N-alkyl-3-aminopyrazoles into azopyrazoles under conditions of membraneless electrolysis in an aqueous solution of NaBr was studied for the first time. It was found that under these conditions the aminopyrazoles, which do not have a substituent at position 4, transform into the corresponding 4,4´-dibromoazopyrazoles. The corresponding yield was in the interval of 28—80%, depending on the structure of the products. The transformation of 4-substituted aminopyrazoles resulted in the formation of azopyrazoles in the yields lying within 62—86% when this process was implemented under conditions with the anodically generated Br2 acting as a mediator. A convenient method of anodic synthesis of azopyrazoles in an aqueous medium without the use of additives of chemical oxidants was proposed. The process is environmentally sound and is characterized by a high atom efficiency (>85%).

Mediated electrochemical synthesis of copper nanoparticles in solution

Environmentally friendly mediated electrochemical synthesis of copper nanoparticles in the solution using a copper anode as a source of copper ions has been realized for the first time. It is shown that at the potential of the redox pair MV2+/MV•+ methylviologen MV2+ is able to mediate a reduction of Cu2+ ions in 60% aqueous DMF/0.1 M Bu4NBF4. Copper nanoparticles build large aggregates (200—250 nm) in the absence of a stabilizer. The use of polyvinylpyrrolidone as a stabilizer makes it possible to obtain smaller copper nanoparticles (20—50 nm) of spherical and oval shape and to characterize them by physicochemical methods.