1409972-47-9Relevant academic research and scientific papers
New Alkylidyne Complexes Featuring a Flexible Trianionic ONO3- Pincer-Type Ligand: Inorganic Enamine Effect versus Sterics in Electrophilic Additions
VenkatRamani, Sudarsan,Huff, Nicholas B.,Jan, Muhammad Tariq,Ghiviriga, Ion,Abboud, Khalil A.,Veige, Adam S.
, p. 2841 - 2848 (2015)
Metal-carbon multiple bonds exhibit enhanced nucleophilicity at the α carbon within ONO trianionic pincer alkylidyne complexes. Defined as the inorganic enamine effect, this phenomenon is a result of the overlap of the N atom lone pair within the ONO3- ligand and a π bond from the metal-carbon multiple bond. Treating the proligand [OCH2NCH2O]H3 (2) with (tBuO)3W≡ CR (where R = Et, tBu) results in the formation of the dianionic pincer complexes [OCH2NHCH2O]W≡ CR(OtBu) (where R = Et (3-Et), tBu (3-tBuanti)). Deprotonation of 3-tBuanti by treatment with Ph3P=CH2 forms the anionic alkylidyne complex {[OCH2NCH2O]W≡ CtBu(OtBu)}{CH3PPh3} (4-tBu). DFT calculations modeling 4-tBu reveal overlap of the N atom lone pair with a W≡ C π bond. However, 4-tBu reacts with electrophiles preferentially at the pincer N atom as opposed to the W≡ Cα group. Multinuclear NMR spectroscopy, combustion analysis, and single-crystal X-ray crystallography are employed to characterize complexes 3-Et, 3-tBuanti, and 4-tBu. (Chemical Equation Presented).
ONO PINCER LIGANDS AND ONO PINCER LIGAND COMPRISING METAL COMPLEXES
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, (2012/12/13)
Embodiments of the invention are directed to ONO pinccr ligands that can be in a trianionic, protonated or protonated equivalent form. The ONO pincer ligand can be combined with a transition metal comprising compound to form an ONO pincer ligand comprising transition metal complex. By choice of the ONO pincer ligand structure, the steric and electronic properties of the transition metal complexes therefrom can be controlled. The ONO pincer ligands comprise a central nitrogen atom that is disubstituted with a pair of three atom comprising bridges where the three atoms are three sp2 hybridized carbons or the three atoms are a pair of sp2 hybridized carbons and an sp3 hybridized carbon or silicon.
