Tetrasubstituted Guanidinate Anions as Supporting Ligands in Organoyttrium Chemistry

Addition of N(SiMe3)2 anion equivalents to iPrNCNiPr followed by reaction with YCl3 generated the dimeric complex {[(Me3Si)2NC(NiPr)2]2Y(μ-Cl)}2 (2). Complex 2 has proven to be an excellent starting material for preparation of a series of hydrocarbyl and amido products, [(Me3Si)2NC(NiPr)2]2YCH(SiMe3)2 (3), [(Me3Si)2NC(NiPr)2]2YN(SiMe3)2 (4), [(Me3Si)2NC(NiPr)2]2Y(μ-Me)2Li[Me2NCH2CH2NMe2] (5), and [(Me3Si)2NC(NiPr)2]2YC(CH3)3 (6). Definitive evidence for the molecular structures of 2, 3, 5, and 6 is provided through single-crystal X-ray analyses, which are presented. These results provide the first reported examples of organoyttrium complexes supported by a guanidinate ligand.