Methylidene Rare-Earth-Metal Complex Mediated Transformations of CN, NN and NH Bonds: New Routes to Imido Rare-Earth-Metal Clusters

Three new patterns of reactivity of rare-earth metal methylidene complexes have been established and thus have resulted in access to a wide variety of imido rare-earth metal complexes [L3Ln3(2-Me)3(3-Me)(-NR)] (L=[PhC(NC6H3iPr2-2,6)2]-; R=Ph, Ln=Y (2a), Lu (2b); R=2,6-Me2C6H3, Ln=Y (3a), Lu (3b); R=p-ClC6H4, Ln=Y (4a), Lu (4b); R=p-MeOC6H4, Ln=Y (5a), Lu (5b); R=Me2CHCH2CH2, Ln=Y (6a), Lu (6b)) and [{L3Lu3(2-Me)3(3-Me)}2(-NRN)] (R=(CH2)6 (7b), (C6H4)2 (8b)). Complex 2b was treated with an excess of CO2 to give the corresponding carboxylate complex [L3Lu3(-1:1-O2CCH3)3(-1:2-O2C-CH3)(-1:1:2-O2CNPh)] (9b) easily. Complex 2a could undergo the selective 3-Me abstraction reaction with phenyl acetylene to give the mixed imido/alkynide complex [L3Y3(2-Me)3(3-1:1:3-NPh)(3-CCPh)] (10a) in high yield. Treatment of 2 with one equivalent of thiophenol gave the selective 3-methyl-abstracted products [L3Ln3(2-Me)3(3-1:1:3-NPh)(3-SPh)] (Ln=Y (11a); Lu (11b). All new complexes have been characterized by elemental analysis, NMR spectroscopy, and most of the structures confirmed by X-ray diffraction.