Hoveyda–Grubbs-type catalysts containing N,N′-dineopentyl- and N,N′-dicyclohexyl-substituted N-heterocyclic carbene (NHC) ligands with syn and anti phenyl groups on the ring backbone were synthesized and fully characterized. The catalytic potential of these complexes was investigated in metathesis reactions of both standard and renewable substrates. Compared to the Hoveyda–Grubbs second generation catalyst (HGII)
to the application of several alkyl organometallic nucleophiles (e.g., alkyl-zinc, boron, and magnesium) in asymmetric cross-couplings, more easily accessible alkylzirconocene reagents have received much less attention. Herein, we report a visible-light-induced, Ni-catalyzed, asymmetric cross-coupling of gem-borazirconocene alkenes with aryl and unactivated alkylhalides, furnishing a diverse series