66464-21-9Relevant academic research and scientific papers
n-Butyllithium/N,N,N',N'-tetramethylethylenediamine-mediated ortholithiations of aryl oxazolines: Substrate-dependent mechanisms
Chadwick, Scott T.,Ramirez, Antonio,Gupta, Lekha,Collum, David B.
, p. 2259 - 2268 (2007)
n-Butyllithium/N,N,N′,N′-tetramethylethylenediamine-mediated ortholithiations of aryloxazolines are described. Methyl substituents on the aryloxazoline and substituents at the meta position of the arenes (methoxy, oxazolinyl, and fluoro) influence the rates and the mechanisms. Monomer- and dimer-based reactions are implicated. Density functional calculations probe details of the mechanism and suggest the origins of cooperative effects in meta-substituted aryl oxazolines.
An update on WII and MoII carbonyl precursors and their application in the synthesis of potentially bio-inspired thiophenolate-oxazoline complexes
Peschel, Lydia M.,Schachner, Joerg A.,Sala, Chris H.,Belaj, Ferdinand,Moesch-Zanetti, Nadia C.
, p. 1559 - 1567 (2013/08/23)
The synthesis of two new low-valent dicarbonyl complexes of tungsten [W(CO)2(SPh-oz)2] (3b) and molybdenum [Mo(CO) 2(SPh-oz)2] (4b) coordinated by a bidentate thiolate-oxazoline ligand SPh-oz is reported. The thereby created coordination via two anionic sulfur atoms can be seen as biologically inspired as it reflects the first coordination sphere of the pterin cofactor found in molybdenum and tungsten enzymes. The in-situ preparation of the lithium salt Li(SPh-oz) (1) was described previously in literature, but analytical data was not available. A similar situation was found for the published syntheses of the low-valent metal precursors [W(CO)3(PPh3)2Cl2] (2a), [W2(CO)7Br4] (3a) and [Mo(CO) 4Br2] where experimental procedures were unreliable and experimental data was inadequate or missing.To the best of our knowledge this is the first report of a full characterization of the literature known compounds Li(SPh-oz) (1), [W(CO)3(PPh3)2Cl2] (2a) and [W2(CO)7Br4] (3a). Furthermore the novel tetranuclear Mo-precursor [Mo4(CO)7Br10] (4a) was synthesized. The symmetric and asymmetric IR stretching frequencies of its seven carbonyl ligands were calculated using DFT and related to the experimental values. The molecular structures of the novel precursor compounds [W(CO)2(PPh3)2Cl2] (2a'), [PPh 3Cl]2[WCl6] (2b), [Mo4(CO) 7Br10] (4a), the two complexes with the SPh-oz ligand [W(CO)2(SPh-oz)2] (3b), [Mo(CO)2(SPh-oz) 2] (4b) and a new modification of [W2(CO) 7Br4] (3a) were determined by single-crystal X-ray diffraction analysis. Copyright
Aryl-oxazoline chelates of first-row transition metals: Structures of {Κ-C,N-(o-C6H4)CMe2(COCH 2CMe2N)}FeCl(py) and [(Κ-C,N-(o-C6H 4)CMe2(COCH2CMe2N)}Cr(μ-Cl)] 2
Volpe, Emily C.,Manke, David R.,Bartholomew, Erika R.,Wolczanski, Peter T.,Lobkovsky, Emil B.
scheme or table, p. 6642 - 6652 (2011/02/27)
Aryl-oxazoline synthons have been explored for the preparation of strong-field first-row transition metal chelate species. With 4,4-dimethyl-2-phenyloxazoline (HPhOx), no CH bond activations afforded complexation, and aside from Zn(Κ-C,N-4,4-Me2-2-(o-C 6H4)oxazoline)2 (Zn(PhOx)2), aryl-coupling reactions were noted with 4,4-dimethyl-2-(2-lithiophenyl)oxazoline (LiPhOx) and MX2; [Κ-N,N-{4,4-Me2-(2-o-C 6H4)-2-oxazoline}2]CoCl2 (1-Co) was structurally characterized. Metalations with 4,4-dimethyl-2-benzyloxazoline (PhCH2Ox) were prone to deprotonation, as exemplified by (Me 2N)3Ti(η-N-(4,4-dimethyl-(2-CHPh)oxazoline)) (2) and bis-N,N′-(4,4-dimethyl-(2-pyridylmethylyl)oxazoline)Fe (3). Oxidative addition of 4,4-dimethyl-2-(2-bromophenylpropan-2-yl)oxazoline (BrPhCMe 2Ox) to Ni(COD)2 provided [{Κ-C,N-(o-C 6H4)CMe2(COCH2CMe 2N)}Ni]2(μ-Br)2 (42). With 4,4-dimethyl-2-(2-lithiophenylpropan-2-yl)oxazoline (LiPhCMe2Ox), salt (FeBr2) metathesis proved uncompetitive with oxazoline ring-opening, as exhibited by [{Κ-N,O-C6H4CMe 2C=NCMe2CH2(μ-O)-}BrFe{Κ-N,O-C 6H4CMe2C=NCMe2CH2(μ-O) -}FeBr]Li {Κ-N,O-C6H4CMe2-C=NCMe 2CH2(μ-O)-}(DME) (5-Fe2Li). Metatheses utilizing (PhCMe2Ox)2Zn, prepared from LiPhCMe 2Ox and ZnCl2, gave structurally characterized dichromium, i.e., [{Κ-C,N-(o-C6H4)CMe2 (COCH 2CMe2N)}Cr]2(μ-Cl)2 (6 2), and iron, i.e., {Κ-C,N-{(o-C6H 4)CMe2(COCH2CMe2N)}Fe(py)Cl (7) products. Bis-aryloxazoline metal complexes proved difficult to prepare, with {Κ-C,N-(o-C6H4)CMe2(COCH 2CMe2N)}2M (M = Ni, 9) the only clear example, although NMR evidence exists for M = Fe (8).
