The selective arylation of unactivated β or challenging γ primary and secondary β-C(sp3)–H bonds has been developed with a Cp*Rh(III) catalyst assisted by a trimethylpyrazole group. A rarely reported six-membered rhodacycle has been identified in rhodium-catalyzed C(sp3)–H activation reactions. Preliminary mechanistic studies have revealed that a concerted metalation–deprotonation pathway might be involved in the C–H activation step.