A TEMPO-like nitroxide combined with an alkyl-substituted pyridine: An efficient catalytic system for the selective oxidation of alcohols with iodine

Recent advancements in the use of Bobbitt's salt and 4-acetamidoTEMPO

Recent advances in synthetic methodologies for selective, oxidative transformations using Bobbitt's salt (4-acetamido-2,2,6,6-tetramethyl-1-oxopiperidinium tetrafluoroborate, 1) and its stable organic nitroxide counterpart ACT (4-acetamidoTEMPO, 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxyl, 2) have led to increased applications across a broad array of disciplines. Current applications and mechanistic understanding of these metal-free, environmentally benign, and easily accessible organic oxidants now span well-beyond the seminal use of 1 and 2 in selective alcohol oxidations. New synthetic methodologies for the oxidation of alcohols, ethers, amines, thiols, C-H bonds and other functional groups with 1 and 2 along with the field's current mechanistic understandings of these processes are presented alongside our contributions in this area. Exciting new areas harnessing the unique properties of these oxidants include: applications to drug discovery and natural product total synthesis, the development of new electrocatalytic methods for depolymerization of lignin and modification of other biopolymers, in vitro and in vivo nucleoside modifications, applications in supramolecular catalysis, the synthesis of new polymers and materials, enhancements in the design of organic redox flow batteries, uses in organic fuel cells, applications and advancements in energy storage, the development of electrochemical sensors, and the production of renewable fuels.

A gram scale selective oxidation of 5-hydroxymethylfurfural to diformylfuran in the presence of oxone and catalyzed by 2-iodobenzenesulfonic acid

In the present work, an alternative system of 5-hydroxymethylfurfural (HMF) oxidation was studied, in an attempt to avoid the use of expensive metal catalysts, polluting systems and high pressures.

Selective Aerobic Oxidation of Benzylic Alcohols Catalyzed by a Dicyclopropenylidene-Ag(I) Complex

The unprecedented synthesis, single-crystal X-ray structure, and first catalytic application of a dicarbene-Ag(I) complex [Ag(BAC)₂][CO₂CF₃] (BAC = bis(diisopropyl)aminocyclopropenylidene) is reported. This novel complex provides a versatile catalytic platform for selective aerobic oxidation of benzylic alcohols to aldehyde or ketone products in high yields. Ease of experimental execution coupled with the use of abundant atmospheric molecular oxygen as an oxidant and low catalyst loading are inherit strengths of these oxidations.

A Multicomponent Electrosynthesis of 1,5-Disubstituted and 1-Aryl 1,2,4-Triazoles

A novel electrochemical route has been developed for the synthesis of 1,5-disubstituted and 1-aryl 1,2,4-triazoles from aryl hydrazines, paraformaldehyde, NH₄OAc, and alcohols. In this multicomponent reaction system, alcohols act as solvents as well as reactants and NH₄OAc is used as the nitrogen source. With the assistance of reactive iodide radical or I₂ and NH₃ electrogenerated in situ, this process could effectively avoid the use of strong oxidants and transition-metal catalysts and be smoothly carried out at room temperature to give a wide array of 1,2,4-triazole derivatives in good to high yields. Preliminary studies reveal that the reaction mechanism involves a radical process.