Divalent Heteroleptic Ytterbium Complexes - Effective Catalysts for Intermolecular Styrene Hydrophosphination and Hydroamination

New heteroleptic Yb(II)-amide species supported by amidinate and 1,3,6,8-tetra-tert-butylcarbazol-9-yl ligands [2-MeOC6H4NC(tBu)N-(C6H3-iPr(2)-2,6)]YbN(SiMe3)(2)(THF) (6) and [1,3,6,8-tBu(4)C(12)H(4)N]Yb[N(SiMe3)(2)](THF)(n) (n = 1 (7), 2 (8)) were synthesized using the amine elimination approach. Complex 6 features an unusual kappa(1)-N,kappa(2)-O,eta(6)-arene coordination mode of the amidinate ligand onto Yb(II). Complexes 7 and 8 represent the first examples of lanthanide complexes with pi-coordination of carbazol-9-yl ligands. Complexes 6 and 7, as well as the amidinate-Yb(II)-amide [tBuC(NC6H3-iPr(2)-2,6)(2)]YbN(SiMe3)(2)(THF) (5), are efficient pre-catalysts for the intermolecular hydrophosphination and hydroamination of styrene with diphenylphosphine, phenylphosphine, and pyrrolidine to give exclusively the anti-Markovnikov monoaddition product. For both types of reaction, the best performances were observed with carbazol-9-yl complex 7 (TONs up to 92 and 48 mol/mol at 60 degrees C, respectively).