Browse
Submit Data
Databases
API
Help

Dataset Information

24 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Isolation, structure and reactivity of a scandium boryl oxycarbene complex.

ABSTRACT: The reaction of a half-sandwich scandium boryl complex 1 with CO (1 atm) afforded a novel boryl oxycarbene complex 2. The structure of 2 was characterized by ¹H, ¹³C and ¹¹B NMR, X-ray diffraction, and DFT analysis. Further reaction of 2 with CO (1 atm) yielded a phenylamido- and boryl-substituted enediolate complex 3 through C-C bond formation between CO and the carbene unit in 2 and cleavage and rearrangement of the Si-N bond in the silylene-linked Cp-amido ligand. Upon heating, insertion of the carbene atom into a methine C-H bond in the boryl ligand of 2 took place to give an alkoxide complex 4. The reactions of 2 with pyridine and 2-methylpyridine led to insertion of the carbene atom into an ortho-C-H bond of pyridine and into a methyl C-H bond of 2-methylpyridine, respectively. The reaction of 2 with ethylene yielded a borylcyclopropyloxy complex 7 through cycloaddition of the carbene atom to ethylene.

SUBMITTER: Wang B

PROVIDER: S-EPMC5580044 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Isolation, structure and reactivity of a scandium boryl oxycarbene complex.

Wang Baoli B Kang Xiaohui X Nishiura Masayoshi M Luo Yi Y Hou Zhaomin Z

Chemical science 20150916 1

The reaction of a half-sandwich scandium boryl complex 1 with CO (1 atm) afforded a novel boryl oxycarbene complex 2. The structure of 2 was characterized by 1H, 13C and 11B NMR, X-ray diffraction, and DFT analysis. Further reaction of 2 with CO (1 atm) yielded a phenylamido- and boryl-substituted enediolate complex 3 through C-C bond formation between CO and the carbene unit in 2 and cleavage and rearrangement of the Si- ...[more]

PMID: 28966773

Similar Datasets

Orthogonal reactivity in boryl-substituted organotrifluoroborates.

Project description:A method was developed for the hydroboration of alkenyl-containing organotrifluoroborates to generate dibora intermediates. The reactivity differences between organotrifluoroborates and trialkylboranes facilitated the cross-coupling of the borane moiety of these intermediates in a highly chemoselective fashion with aryl halides, leaving the trifluoroborate intact for subsequent transformation. A one-pot hydroboration/two-directional cross-coupling sequence was also demonstrated, providing the fully elaborated products in good yields. These conditions were also amenable in the cross-coupling of trialkylboranes to halo-containing organotrifluoroborates. The stability of the trifluoroborate moiety to these conditions allows simple and efficient strategies for complex molecule construction.

| S-EPMC2645949 | biostudies-literature

Mapping the Electronic Structure and the Reactivity Trends for Stabilized α-Boryl Carbanions.

Project description:The chemistry of stabilized α-boryl carbanions shows remarkable diversity, and can enable many different synthetic routes towards efficient C-C bond formation. The electron-deficient, trivalent boron center stabilizes the carbanion facilitating its generation and tuning its reactivity. Here, the electronic structure and the reactivity trends of a large dataset of α-boryl carbanions are described. DFT-derived parameters were used to capture their electronic and steric properties, computational reactivity towards model substrates, and crystallographic analysis within the Cambridge Structural Dataset. This study maps the reactivity space by systematically varying the nature of the boryl moiety, the substituents of the carbanionic center, the number of α-boryl motifs, and the metal counterion. In general, the free carbanionic intermediates are described as borata-alkene species with C-B π interactions polarized towards the carbon. Furthermore, it was possible to classify the α-boryl alkylidene metal precursors into three classes directly related to their reactivity: 1) nucleophilic borata-alkene salts with alkali and alkaline earth metals, 2) nucleophilic η2 -(C-B) borata-alkene complexes with early transition metals, Cu and Ag, and 3) α-boryl alkyl complexes with late transition metals. This trend map aids selection of the appropriate reactive synthon depending on the reactivity sought.

| S-EPMC8457114 | biostudies-literature

Synthesis and versatile reactivity of scandium phosphinophosphinidene complexes.

Project description:M=E/M≡E multiple bonds (M = transition metal, E = main group element) are of significant fundamental scientific importance and have widespread applications. Expanding the ranges of M and E represents grand challenges for synthetic chemists and will bring new horizons for the chemistry. There have been reports of M=E/M≡E multiple bonds for the majority of the transition metals, and even some actinide metals. In stark contrast, as the largest subgroup in the periodic table, rare-earth metals (Ln) were scarcely involved in Ln=E/Ln≡E multiple bonds. Until recently, there were a few examples of rare-earth monometallic alkylidene, imido and oxo complexes, featuring Ln=C/N/O bonds. What are in absence are rare-earth monometallic phosphinidene complexes with Ln=P bonds. Herein, we report synthesis and structure of rare-earth monometallic phosphinidene complexes, namely scandium phosphinophosphinidene complexes. Reactivity of scandium phosphinophosphinidene complexes is also mapped out, and appears to be easily tuned by the supporting ligand.

| S-EPMC7283324 | biostudies-literature

The Synthesis and Structure of a Scandium Nitrate Hydroxy-Bridged Dimeric Complex Supported by Bipyridyl Ligands.

Project description:The current discussion on whether scandium, yttrium and lanthanum should represent Group 3 in the Periodic Table or whether lutetium should replace lanthanum in the group has prompted us to further explore the structural chemistry of the Group 3 elements and compare the coordination numbers and coordination geometries adopted. The steric and electronic properties of the coordinated ligands have a major influence on the structures adopted. We report the synthesis and crystal structure determination of an unusual dinuclear scandium complex [(bipy)(NO3)2Sc(µ-OH)2Sc(NO3)2(bipy)] obtained by the reaction of hydrated scandium nitrate with 2,2'-bipyridyl (bipy) in either ethanol or nitromethane. The crystal structure of the complex shows that the scandium centers are eight coordinate, and the structure obtained contrasts with related complexes found in the lanthanide series [Ln(bipy)2(NO3)3] and [Ln(phen)2(NO3)3] (phen = phenanthroline) and in [M(terpy)(NO3)3] (M = Sc, Er-Lu), where these complexes are all mononuclear.

| S-EPMC8954743 | biostudies-literature

Crystal structure of hy-droxy scandium nitrate chloride.

Project description:Each Sc3+ ion in the title salt, di-μ-hydroxido-bis-[tri-aqua-(nitrato-κ2 O,O')scandium(III)] dichloride, [Sc2(NO3)2(OH)2(H2O)6]Cl2, is coordinated by a nitrate anion, two hydroxide ions and three water mol-ecules to generate a distorted penta-gonal-bipyramidal ScO7 coordination polyhedron. The complete {[(NO3)(μ-OH)Sc(H2O)3]2}2+ ion is generated by crystallographic inversion symmetry. The nitrate anion binds in a bidentate fashion whereas the hydroxide ions are bridged between two Sc centers. Two charge-balancing Cl- ions are located in the outer sphere. In the extended structure, O-H⋯O and O-H⋯Cl hydrogen bonds connect the components into a three-dimensional network.

| S-EPMC6505614 | biostudies-literature

Scandium Reduced Arene Complex: Protonation and Reaction with Azobenzene.

Project description:The reactivity of the reduced anthracene complex of scandium [Li(thf)3 ][Sc{N(tBu)Xy}2 (anth)] (2-anth-Li) (Xy=3,5-Me2 C6 H3 ; anth=C14 H10 2- , thf=tetrahydrofuran) toward Brønsted acid [NEt3 H][BPh4 ] and azobenzene is reported. While a stepwise protonation of 2-anth-Li with two equivalents of [NEt3 H][BPh4 ] afforded the scandium cation [Sc{N(tBu)Xy}2 (thf)2 ][BPh4 ] (3), reduction of azobenzene gave a thermolabile, anionic scandium reduced azobenzene complex [Li(thf)][Sc{N(tBu)Xy}2 (η2 -PhNNPh)] (4), which slowly lost one of the anilide ligands to form the neutral scandium azobenzene complex dimer [Sc{N(tBu)Xy}(μ-η2 :η2 -Ph2 N2 )]2 (5). Exposure of 3 to CO2 produced the scandium carbamate complex [Sc{κ2 -O2 CN(tBu)(Xy)}2 ][BPh4 ] (6) as a result of CO2 insertion into the Sc-N bonds. In an attempt to prepare scandium hydrides, the reaction of 3 with the hydride sources LiAlH4 and Na[BEt3 H] led to the terminal aluminum hydride [AlH{N(tBu)Xy}2 (thf)] (7) and the scandium n-butoxide [Sc{N(tBu)(Xy)}2 (μ-OnBu)] (8) after Sc/Al transmetalation and nucleophilic ring-opening of THF, respectively. All reported compounds isolated in moderate to good yields were fully characterized.

| S-EPMC8596697 | biostudies-literature

Enhanced electron-transfer reactivity of nonheme manganese(IV)-oxo complexes by binding scandium ions.

Project description:One and two scandium ions (Sc(3+)) are bound strongly to nonheme manganese(IV)-oxo complexes, [(N4Py)Mn(IV)(O)](2+) (N4Py = N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) and [(Bn-TPEN)Mn(IV)(O)](2+) (Bn-TPEN = N-benzyl-N,N',N'-tris(2-pyridylmethyl)-1,2-diaminoethane), to form Mn(IV)(O)-(Sc(3+))1 and Mn(IV)(O)-(Sc(3+))2 complexes, respectively. The binding of Sc(3+) ions to the Mn(IV)(O) complexes was examined by spectroscopic methods as well as by DFT calculations. The one-electron reduction potentials of the Mn(IV)(O) complexes were markedly shifted to a positive direction by binding of Sc(3+) ions. Accordingly, rates of the electron transfer reactions of the Mn(IV)(O) complexes were enhanced as much as 10(7)-fold by binding of two Sc(3+) ions. The driving force dependence of electron transfer from various electron donors to the Mn(IV)(O) and Mn(IV)(O)-(Sc(3+))2 complexes was examined and analyzed in light of the Marcus theory of electron transfer to determine the reorganization energies of electron transfer. The smaller reorganization energies and much more positive reduction potentials of the Mn(IV)(O)-(Sc(3+))2 complexes resulted in remarkable enhancement of the electron-transfer reactivity of the Mn(IV)(O) complexes. Such a dramatic enhancement of the electron-transfer reactivity of the Mn(IV)(O) complexes by binding of Sc(3+) ions resulted in the change of mechanism in the sulfoxidation of thioanisoles by Mn(IV)(O) complexes from a direct oxygen atom transfer pathway without metal ion binding to an electron-transfer pathway with binding of Sc(3+) ions.

| S-EPMC3934761 | biostudies-literature

Electronic Structure and Core Spectroscopy of Scandium Fluoride Polymorphs.

Project description:Microscopic knowledge of the structural, energetic, and electronic properties of scandium fluoride is still incomplete despite the relevance of this material as an intermediate for the manufacturing of Al-Sc alloys. In a work based on first-principles calculations and X-ray spectroscopy, we assess the stability and electronic structure of six computationally predicted ScF3 polymorphs, two of which correspond to experimentally resolved single-crystal phases. In the theoretical analysis based on density functional theory (DFT), we identify similarities among the polymorphs based on their formation energies, charge-density distribution, and electronic properties (band gaps and density of states). We find striking analogies between the results obtained for the low- and high-temperature phases of the material, indirectly confirming that the transition occurring between them mainly consists of a rigid rotation of the lattice. With this knowledge, we examine the X-ray absorption spectra from the Sc and F K-edge contrasting first-principles results obtained from the solution of the Bethe-Salpeter equation on top of all-electron DFT with high-energy-resolution fluorescence detection measurements. Analysis of the computational results sheds light on the electronic origin of the absorption maxima and provides information on the prominent excitonic effects that characterize all spectra. A comparison with measurements confirms that the sample is mainly composed of the high- and low-temperature polymorphs of ScF3. However, some fine details in the experimental results suggest that the probed powder sample may contain defects and/or residual traces of metastable polymorphs.

| S-EPMC10015455 | biostudies-literature

Reactivity and Structure of a Bis-phenolate Niobium NHC Complex.

Project description:We report the facile synthesis of a rare niobium(V) imido NHC complex with a dianionic OCO-pincer benzimidazolylidene ligand (L 1 ) with the general formula [NbL 1 (N t Bu)PyCl] 1-Py. We achieved this by in situ deprotonation of the corresponding azolium salt [H 3 L 1 ][Cl] and subsequent reaction with [Nb(N t Bu)Py 2 Cl 3 ]. The pyridine ligand in 1-Py can be removed by the addition of B(C6F5)3 as a strong Lewis acid leading to the formation of the pyridine-free complex 1. In contrast to similar vanadium(V) complexes, complex 1-Py was found to be a good precursor for various salt metathesis reactions, yielding a series of chalcogenido and pnictogenido complexes with the general formula [ NbL 1 (N t Bu)Py(EMes)] (E = O (2), S (3), NH (4), and PH (5)). Furthermore, complex 1-Py can be converted to alkyl complex (6) with 1 equiv of neosilyl lithium as a transmetallation agent. Addition of a second equivalent yields a new trianionic supporting ligand on the niobium center (7) in which the benzimidazolylidene ligand is alkylated at the former carbene carbon atom. The latter is an interesting chemically "noninnocent" feature of the benzimidazolylidene ligand potentially useful in catalysis and atom transfer reactions. Addition of mesityl lithium to 1-Py gives the pyridine-free aryl complex 8, which is stable toward "overarylation" by an additional equivalent of mesityl lithium. Electrochemical investigation revealed that complexes 1-Py and 1 are inert toward reduction in dichloromethane but show two irreversible reduction processes in tetrahydrofuran as a solvent. However, using standard reduction agents, e.g., KC8, K-mirror, and Na/Napht, no reduced products could be isolated. All complexes have been thoroughly studied by various techniques, including 1H-, 13C{1H}-, and 1H-15N HMBC NMR spectroscopy, IR spectroscopy, and X-ray diffraction analysis.

| S-EPMC9896488 | biostudies-literature

Boryl (Hetero)aryne Precursors as Versatile Arylation Reagents: Synthesis through C-H Activation and Orthogonal Reactivity.

Project description:(Pinacolato)boryl ortho-silyl(hetero)aryl triflates are presented as a new class of building blocks for arylation. They demonstrate unique versatility by delivering boronate or (hetero)aryne reactivity chemoselectively in a broad range of transformations. This approach enables the unprecedented postfunctionalization of fluoride-activated (hetero)aryne precursors, for example, as substrates in transition-metal catalysis, and offers valuable new possibilities for aryl boronate postfunctionalization without the use of specialized protecting groups.

| S-EPMC4600243 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data