Researchers at the Shanghai Institute of Organic Chemistry of the Chinese Academy of Sciences have developed a method to generate carbon radicals through metal-to-ligand charge transfer (MLCT). The process has potential applications in photocatalysis, organic synthesis and energy conversion.
Without an effective follow-up reaction, conventional MLCT is reversible. To overcome this limitation, the team designed and isolated copper-sulfone complexes. They remain stable in the dark for more than three years at room temperature.
Under visible light, the ligand in the complexes undergoes irreversible fragmentation, producing alkyl radicals. The method can generate both fluorinated and non-fluorinated alkyl radicals, including methyl radicals. The researchers used it to alkylate alkenes, arenes and alkynes.
