Language：English   Publisher：Angewandte Chemie - International Edition  

Catalytic systems using a small amount of organic photosensitizer for the activation of an inorganic (on-demand ligand-free) nickel(II) salt represent a cost-effective method for cross-coupling reactions, while C(sp2)−O bond formation remains less developed. Herein, we report a strategy for the synthesis of phenols with a nickel(II) salt and an organic photosensitizer, which was identified via an investigation into the catalytic activity of 60 organic photosensitizers consisting of various electron donor and acceptor moieties. To examine the effect of multiple intractable parameters on the catalytic activity of photosensitizers, machine-learning (ML) models were developed, wherein we embedded descriptors representing their physical and structural properties, which were obtained from DFT calculations and RDKit, respectively. The study clarified that integrating both DFT- and RDKit-derived descriptors in ML models balances higher “precision” and “recall” across a wide range of search space relative to using only one of the two descriptor sets.

DOI： 10.1002/anie.202219107

Web of Science

Scopus

PubMed

DOI： 10.1021/acscatal.2c0503415400ACS

Web of Science

Publisher：ACS Catalysis  

Organic photoredox catalysts (OPCs) have the potential to replace precious-metal-based photoredox catalysts (PMPCs). Compared with strongly oxidizing OPCs, such as the representative acridinium salts, however, the recent development of strongly reducing OPCs has been relatively sluggish. In this Perspective, strongly reducing OPCs bearing arylamine motifs are introduced. One of the advantages of OPCs is their versatility in catalyst design, which makes it easier to develop catalysts with a reducing capability superior to that of fac-[Ir(ppy)3], which is the strongest reductant among the commonly used PMPCs. Easy access to structural diversity also contributes to the rapid development of appropriate catalysts for various applications, for instance, not only simple organo-radical reactions but also precise control of polymer synthesis and properties through photocatalytic (organocatalyzed) atom-transfer radical polymerization. While light with a shorter wavelength (higher energy), such as near-ultraviolet light, is typically involved in conferring OPCs with their strongly reducing natures, strategies to develop strongly reducing catalytic systems using a longer wavelength (lower energy) of visible light, including consecutive photoinduced electron transfer, are emerging as a defacto standard. These strategies for the design of OPC systems, which allow them to achieve otherwise inaccessible reactions using visible light, are also described.

DOI： 10.1021/acscatal.2c05034

Web of Science

Scopus

Language：English  

DOI： 10.1039/d0cc08060h

PubMed