Novel radical transfer reagents under photoirradiation conditions were developed by the use of benzothiazoline derivatives.

Supramolecular photocatalysis via charge-transfer excitation of a host-guest complex was developed by use of the macrocyclic boronic ester [2+2] BTH-F containing highly electron-deficient difluorobenzothiadiazole moieties. In the presence of a catalytic amount of [2+2] BTH-F , the triplet excited state of anthracene was generated from the charge-transfer excited state of anthracene@[2+2] BTH-F by visible-light irradiation, and cycloaddition of the excited anthracene with several dienes and alkenes proceeded in a [4+2] manner in high yields.

Developed herein is a visible-light-driven synthesis of sulfides by an electron donor–acceptor/single electron transfer and hydrogen atom transfer combined system without transition metals and strong oxidants. This reaction proceeds through the excitation of an electron donor–acceptor complex between a thiolate and an aryl halide, followed by the hydrogen atom transfer from an alkane to the generated aryl radical.

Electron donor–acceptor (EDA) complex-mediated single-electron transfer (SET) is a crucial method for generating carbon radicals. Hydrogen atom transfer (HAT) enables the direct generation of alkyl radicals. We report a dual-role EDA-SET/HAT photoreaction system for carbon–carbon bond formation using a phenol catalyst and aryl iodide. This system facilitates addition of alkyl radicals generated from ethers, amide, sulfide, and cycloalkane to arenes. Mechanistic studies revealed that EDA complex formation is mediated by halogen bonding between phenoxide and aryl iodide. Irradiation of the EDA complex with visible light generates an aryl radical, which abstracts a hydrogen atom from an sp3 carbon to form an alkyl radical.