Iron-Catalyzed C(sp 3 )-H Alkylation through Ligand-to-Metal Charge Transfer

We report the FeCl (3) -catalyzed alkylation of nonactivated C(sp (3) )-H bonds. Photoinduced ligand-to-metal charge transfer at the iron center generates chlorine radicals that then preferentially abstract hydrogen atoms from electron-rich C(sp (3) )-H bonds distal to electron-withdrawing functional groups. The resultant alkyl radicals are trapped by electron-deficient olefins, and the catalytic cycle is closed by Fe(II) recombination and protodemetalation.

Automated summary

The FeCl (3) -catalyzed alkylation of nonactivated C(sp (3) )-H bonds is reported, involving photoinduced ligand-to-metal charge transfer and generation of chlorine radicals, which abstract hydrogen atoms from electron-rich C(sp (3) )-H bonds distal to electron-withdrawing functional groups. The resulting alkyl radicals react with electron-deficient olefins, and the catalytic cycle is closed through Fe(II) recombination and protodemetalation.