Recent Advances in Synthetic Methods by Photocatalytic Single-Electron Transfer Chemistry of Pyridine -Oxides.

By adoption of the enabling technology of modern photoredox catalysis and photochemistry, the generation of reactive and versatile pyridine -oxy radicals can be facilely achieved from single-electron oxidation of pyridine -oxides. This Synopsis highlights recent methodologies mediated by pyridine -oxy radicals in developing (1) pyridine -oxide-based hydrogen atom transfer catalysts for C(sp)-H functionalizations and (2) β-oxyvinyl radical-mediated cascade reactions. In addition, recent research revealed that direct photoexcitation of pyridine -oxides allowed for the generation of alkyl carbon radicals from alkylboronic acids.

Hydroboration of Nitriles, Esters, and Carbonates Catalyzed by Simple Earth-Abundant Metal Triflate Salts.

During the past decade earth-abundant metals have become increasingly important in homogeneous catalysis. One of the reactions in which earth-abundant metals have found important applications is the hydroboration of unsaturated C-C and C-X bonds (X=O or N). Within these set of transformations, the hydroboration of challenging substrates such as nitriles, carbonates and esters still remain difficult and often relies on elaborate ligand designs and highly reactive catalysts (e.

Stereospecific Assembly of Fused Imidazolidines via Tandem Ring Opening/Oxidative Amination of Aziridines with Cyclic Secondary Amines Using Photoredox Catalysis.

Sustainable assembly of imidazolidines is accomplished via a sequential stereospecific ring opening and C-H amination using aziridines with secondary cyclic amines under visible light mediated indazoloquinoline photoredox catalysis at ambient conditions. Optically active aziridines are coupled with high enantiomeric purities. The computational studies provide insights on the redox properties of the catalysts as well as a profile of the reaction.

Expedient stereospecific Co-catalyzed tandem C-N and C-O bond formation of N-methylanilines with styrene oxides.

Cobalt(ii)-catalyzed stereospecific coupling of N-methylanilines with styrene oxides is developed via tandem C-N and C-O bond formation using tert-butyl hydroperoxide (TBHP) as an oxidant. Optically active epoxide can be reacted with high optical purity.

Copper(II)-Catalyzed Oxidative Coupling of Anilines, Methyl Arenes, and TMSN via C(sp/sp)-H Functionalization and C-N Bond Formation.

Copper(II)-catalyzed cross-coupling of anilines, methyl arenes, and TMSN in the presence of tert-butylhydroperoxide at moderate temperature produced 2-aryl benzimidazoles via a tandem C(sp/sp)-H functionalization and C-N bond formations. The selectivity and multiple C-H functionalization of the simple substrates are significant practical features.

"On Water" C(sp)-H Functionalization/C-O/C-N Bonds Formations: Synthesis of Functionalized Oxazolidines and Imidazolidines.

On water oxidative C(sp)-H functionalization/C-O/C-N bonds formations using tetrabutylammonium iodide as the catalyst and tert-butyl hydroperoxide in water (T-Hydro) as the oxidant affords a potential route for the construction of functionalized oxazolidines and imidazolidines. The reaction is simple, regioselective, and effective at moderate temperature with broad substrate scope. In the case of optically active substrates, the oxidative cyclization can be accomplished with high optical purities.