A copper-catalyzedC(sp3)-Si cross-coupling of aliphatic C(sp3)-I electrophiles using a Si-B reagent as the silicon pronucleophile is reported. The reaction involves an alkyl radical intermediate that also engages in 5-exo-trig ring closures onto pendant alkenes prior to the terminating C(sp3)-Si bond formation. Several Ueno-Stork-type precursors cyclized with excellent diastereocontrol in good yields