Aryl sulfonium salt electron donor-acceptor complexes for halogen atom transfer: Isocyanides as tunable coupling partners

The photoactivation of sulfonium salt EDA (electron donor-acceptor) complexes provides a mild platform for aryl-radical-mediated halogen atom transfer activation of a wide range of functionalized alkyl iodides, including tertiary alkyl iodides. Using an aryl sulfonium salt with carbonate as an inexpensive donor for EDA complex formation, the general reaction platform has been applied in a divergent, metal-free photochemical approach to nitriles and amides. This divergency was made possible by tuning the isocyanide radical traps. For example, the identification of a readily accessible, bench-stable, and crystalline amide containing isocyanide grants access to nitrile products with complete selectivity.