Promoting effect of water on light and phenanthroline-diphosphine Cu(I) complex-initiated iodine atom transfer cyclisation

Photoexcited Transition-Metal Catalyzed Carbon-Halogen Bond Formation

Transition-metal catalysis has proven useful in facilitating carbon-halogen (C-X) bond formation. Despite the vast number of methodologies reported to furnish these bonds, limitations have remained, warranting continued development. The recent surge of metallaphotoredox-based transformations has provided a novel gateway to bypass these limitations. Through the use of photoexcited species, the formation of C-X bonds arise through new mechanistic pathways, finding alternatives to high reaction temperatures and stoichiometric additives. The discovery of this novel strategy has provided access to molecular space that has not been previously attainable. Herein, we report the recent advances on transition-metal photocatalyzed C-X bond formation, in hopes of easing the synthetic endeavours for chemists in industrial and academic laboratories.

Radical Cyclization-Initiated Difunctionalization Reactions of Alkenes and Alkynes

Radical reactions are powerful in the synthesis of diverse molecular scaffolds bearing functional groups. In previous review articles, we have presented 1,2-difunctionalizations, remote 1,3-, 1,4-, 1,5-, 1,6- and 1,7-difunctionalizations, and addition followed by cyclization reactions. Presented in this paper is radical cyclization followed by the second functionalization reaction. The second functionalization could be realized by atom transfer reactions, radical or transition metal-assisted coupling reactions, and reactions with neutral molecules, cationic and anionic species.

Photoactive Copper Complexes: Properties and Applications

Photocatalyzed and photosensitized chemical processes have seen growing interest recently and have become among the most active areas of chemical research, notably due to their applications in fields such as medicine, chemical synthesis, material science or environmental chemistry. Among all homogeneous catalytic systems reported to date, photoactive copper(I) complexes have been shown to be especially attractive, not only as alternative to noble metal complexes, and have been extensively studied and utilized recently. They are at the core of this review article which is divided into two main sections. The first one focuses on an exhaustive and comprehensive overview of the structural, photophysical and electrochemical properties of mononuclear copper(I) complexes, typical examples highlighting the most critical structural parameters and their impact on the properties being presented to enlighten future design of photoactive copper(I) complexes. The second section is devoted to their main areas of application (photoredox catalysis of organic reactions and polymerization, hydrogen production, photoreduction of carbon dioxide and dye-sensitized solar cells), illustrating their progression from early systems to the current state-of-the-art and showcasing how some limitations of photoactive copper(I) complexes can be overcome with their high versatility.