title: Versatile Reactivity of Scorpionate-Anchored Yttrium-Dialkyl Complexes towards Unsaturated Substrates.
abstract: A series of unusual chemical-bond transformations were observed in the reactions of high active yttrium-dialkyl complexes with unsaturated small molecules. The reaction of scorpionate-anchored yttrium-dibenzyl complex [Tp(Me2)Y(CH2Ph)2(thf)] (1, Tp(Me2)=tri(3,5-dimethylpyrazolyl)borate) with phenyl isothiocyanate led to C=S bond cleavage to give a cubane-type yttrium-sulfur cluster, {Tp(Me2)Y(μ3-S)}4 (2), accompanied by the elimination of PhN-C(CH2Ph)2. However, compound 1 reacted with phenyl isocyanate to afford a C(sp(3)) H activation product, [Tp(Me2)Y(thf){μ-η(1):η(3)-OC(CHPh)NPh}{μ-η(3):η(2)-OC(CHPh)NPh}YTp(Me2)] (3). Moreover, compound 1 reacted with phenylacetonitrile at room temperature to produce γ-deprotonation product [(Tp(Me2))2Y](+)[Tp(Me2)Y(N=C=CHPh)3](-) (6), in which the newly formed N=C=CHPh ligands bound to the metal through the terminal nitrogen atoms. When this reaction was carried out in toluene at 120 °C, it gave a tandem γ-deprotonation/insertion/partial-Tp(Me2)-degradation product, [(Tp(Me2)Y)2(μ-Pz)2{μ-η(1):η(3)-NC(CH2Ph)CHPh}] (7, Pz=3,5-dimethylpyrazolyl).
authors.affiliation: Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433 (P. R. China).
authors.forename: Weiyin
authors.initials: W
authors.lastname: Yi
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Fangjun
authors.initials: F
authors.lastname: Zhang
authors.forename: Yin
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zhenxia
authors.initials: Z
authors.lastname: Chen
authors.forename: Xigeng
authors.initials: X
authors.lastname: Zhou
keywords: CH activation; cleavage reactions; heterocycles; insertion; yttrium