Copper-Catalyzed Arylation of Remote C(sp3 )-H Bonds in Carboxamides and Sulfonamides.

Reported herein is an unprecedented copper-catalyzed arylation of remote C(sp3 )-H bonds. Stirring a trifluorotoluene solution of either N-fluorocarboxamides or N-fluorosulfonamides and arylboronic acids in the presence of a catalytic amount of copper(II) trifluoroacetylacetonate, 2,2'-bipyridine, and sodium tert-butoxide afforded the γ- and δ-C(sp3 )-H arylated carboxamides and sulfonamides, respectively, in good to high yields. Mechanistic studies indicate that the reaction might proceed through an amidyl radical generation, 1,5-hydrogen atom transfer (HAT), and copper-catalyzed cross-coupling of the resulting carbon radical with arylboronic acids.