The synthesis of an easily accessible theophylline-derived copper complex with additional ammonium functionalization has been developed.

The synthesis of a family of N‐heterocyclic carbene–copper complexes bearing a sulfur moiety by using different copper(I) halides through convenient procedures is reported. The solid‐state structures of the presented copper compounds were elucidated based on X‐ray crystallographic analysis. The obtained complexes were examined in various catalytic transformations including 1,3‐dipolar cycloaddition of alkynes and azides, A3 coupling reaction, and β‐hydroboration.

A series of modified Hoveyda-Grubbs catalysts incorporating a chelating iodo-benzylidene ligand were prepared and characterized. The presence of electron-withdrawing ring substituents in the para position to the iodide was found to decrease the catalytic activity, revealing that dissociation of the Ru···I-Ar bond is not the rate-determining step.

N‐Aryl‐substituted 2‐nitrosoanilines (=2‐nitrosobenzenamines) 1, readily available by nucleophilic substitution of the ortho‐H‐atom in nitroarenes with arenamines, react with 2‐substituted acetic acid esters in the presence of a weak base giving 1‐arylquinoxalin‐2(1H)‐ones (Scheme 2). This cyclocondensation allows for the synthesis of compounds 2–4, unsubstituted at C(3) or substituted by alkyl, aryl, ester, amide, and keto groups, in good to excellent yields (Tables 1–4).

Heterocycles are important class of structures, which occupy a major space in the domain of natural and bioactive compounds. For this reason, development of new synthetic strategies for their controllable synthesis became of special interests. The development of novel photoredox systems with wide-range application in organic synthesis is particularly interesting. Organic dyes have been widely applied as photoredox catalysts in organic synthesis. Their low costs compared to the typical photocatalysts based on transition metals make them an excellent alternative. This review describes proceedings since 2015 in the area of application of metal-free, visible-light-mediated catalysis for assembling various heterocyclic scaffolds containing five- and six-membered rings bearing nitrogen and oxygen heteroatoms.

In recent years, spirocyclic compounds have attracted a significant interest in medicinal chemistry due to their considerable biological activities. The general and widely used concept for spirocyclic compound synthesis is related with dearomatization of starting material. However, most of the libraries prepared using this concept comprise structure similarity. Therefore, preparation of structurally distinct libraries comprising varied functionality requires different approaches and that includes non-dearomative pathways. In given review recent advance in the synthesis of structurally varied spirocycles via radical-mediated non-dearomative strategies is discussed. In this context, application of radical initiators or photoredox catalysis is described. The variety of the presented examples indicates the high potential of the visible-light-induced methodologies in spirocyclic compound synthesis, which can act as a very efficient green alternative to known procedures, offering mild reaction conditions and high functional group tolerance.

A series of N-heterocyclic copper carbene complexes bearing sulfoxide and sulfone moieties have been prepared. In case of new copper compounds with sulfone ligand, the solid-state structures were determined using X-Ray crystallography. Obtained complexes were investigated as catalysts in such transformations as: 1,3-dipolar cycloaddition of alkynes and azides (CuAAC), A 3 coupling reaction and β-hydroboration and compared with standard copper catalytic systems.

A visible-light-mediated process for dehydrogenation of amines has been described. The given protocol showed a broad substrate scope, mild reaction conditions and excellent results without the requirement of tedious purification.