Redox-Active Leaving Group Enables the Deoxygenative Arylation of Unactivated Aliphatic Alcohols by Thermal, Homogeneous Iron(I)-Catalyzed Cross-Coupling

Aliphatic alcohols were installed with proposed leaving groups for reaction with well defined, 1,3-diketiminesupported (NacNac)iron(I)-(η6-PhMe) metalloradical, indicating a redox-active 2-isoquinolinyl ether substrate to undergo reductive homolytic C(sp3)–O bond cleavage concomitant with alkyl radical generation as determined by PBN spin trap. The optimal isoquinolinyl ether was employed as substrate in Kumada cross-coupling catalyzed by 10 mol% (NacNac)iron(II) chloride, yielding the deoxygenated, arylated product following homolytic C(sp3)–O β-scission. Hexenyl radical clock experiments and catalyst speciation determined by 19F NMR spectroscopy were consistent with intermediacy of alkyl radicals captured by (NacNac)iron(II)–monoaryl resting state, accessing deoxygenated cross-coupled products derived of naturally occurring aliphatic alcohols such as β-sitosterol and isosorbide.