Electrochemically mediated synthesis of cyanated heterocycles from α-amino esters, pyridine-2-carbaldehydes and NH4SCN as cyano group source.

The electrochemically mediated cyanation/annulation process with in situ cyanide ion generation from NH4SCN and multi-step oxidative construction of CN-functionalized heterocycles from easily available α-amino esters and pyridine-2-carbaldehydes has been discovered. Depending on the nature of the α-amino ester, 1-cyano-imidazo[1,5-a]pyridine-3-carboxylates, 3-alkyl- and 3-aryl-imidazo[1,5-a]pyridines-1-carbonitriles, and the first reported 4-oxo-4H-pyrido[1,2-a]pyrazine-1-carbonitriles were obtained. The electrosynthesis is carried out in an undivided electrochemical cell under constant current conditions.

FeCl-Mediated Rearrangement of Aminoperoxides into Functionalized Tetrahydrofurans: Dynamic Non-innocence of O-Ligands at an Fe Center Coordinates a Radical Cascade.

The selective reaction of cyclic aminoperoxides with FeCl proceeds through a sequence of O-O and C-C bond cleavages, followed by intramolecular cyclization, yielding functionalized tetrahydrofurans in 44-82% yields. Replacing the peroxyacetal group in the peroxide structure with a peroxyaminal fragment fundamentally alters the reaction pathway. Instead of producing linear functionalized ketones, this modification leads to the formation of hard-to-access substituted tetrahydrofurans.

Electrochemically Induced Synthesis of -Allyloxyphthalimides via Cross-Dehydrogenative C-O Coupling of -Hydroxyphthalimide with Alkenes Bearing the Allylic Hydrogen Atom.

The electrochemically induced reaction between alkenes, bearing an allylic hydrogen atom, and -hydroxyphthalimide was investigated. Cross-dehydrogenative C-O coupling with phthalimide--oxyl radical, derived from -hydroxyphthalimide, occurs instead of oxidation of the allylic site, with the formation of a carbonyl group or functionalization of the double C=C bond. The discovered transformation proceeds in an undivided electrochemical cell equipped with a carbon felt anode and a platinum cathode.

Ammonium Dinitramide as a Prospective N-NO Synthon: Electrochemical Synthesis of Nitro--Azoxy Compounds from Nitrosoarenes.

In this study, the electrochemical coupling of nitrosoarenes with ammonium dinitramide is discovered, leading to the facile construction of the nitro--azoxy group, which represents an important motif in the design of energetic materials. Compared to known approaches to nitro--azoxy compounds involving two chemical steps (formation of azoxy group containing a leaving group and its nitration) and demanding expensive, corrosive, and hygroscopic nitronium salts, the presented electrochemical method consists of a single step and is based solely on nitrosoarenes and ammonium dinitramide. The dinitramide salt plays the roles of both the electrolyte and reactant for the coupling.