Transfer Hydrogenation Processes toμ3-Alkylidyne Groups on the Organotitanium Oxide [Ti3CpO3]

Andrés, Román; Galakhov, Mikhail; Gómez-Sal, M. Pilar; Martı́n, Avelino; Mena, Miguel; Morales-Varela, María del Carmen; Santamarı́a, Cristina

doi:10.1002/1521-3765(20020215)8:4<805::aid-chem805>3.0.co;2-h

Cited by 15 publications

(2 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The 13 C NMR spectra show the resonances for the ketimido group carbons (>CN-) at δ = 170.2 ( 5 ), 170.4 ( 6 ), and 171.7 ( 7 ), in the same range as that reported for the trinuclear species [{Ti(η 5 -C 5 Me 5 )(μ-O)} 3 (μ-CHR)(NCPh 2 )] (R = H, Me) . The IR spectra of 5 – 7 reveal ν(NC) IR frequencies around 1630–1639 cm –1 , which are consistent with κN-ketimido moieties …”

Section: Resultssupporting

confidence: 55%

Carbon–Nitrogen Bond Construction and Carbon–Oxygen Double Bond Cleavage on a Molecular Titanium Oxonitride: A Combined Experimental and Computational Study

et al. 2015

Self Cite

View full text Add to dashboard Cite

New carbon-nitrogen bonds were formed on addition of isocyanide and ketone reagents to the oxonitride species [{Ti(η(5)-C5Me5)(μ-O)}3(μ3-N)] (1). Reaction of 1 with XylNC (Xyl = 2,6-Me2C6H3) in a 1:3 molar ratio at room temperature leads to compound [{Ti(η(5)-C5Me5)(μ-O)}3(μ-XylNCCNXyl)(NCNXyl)] (2), after the addition of the nitrido group to one coordinated isocyanide and the carbon-carbon coupling of the other two isocyanide molecules have taken place. Thermolysis of 2 gives [{Ti(η(5)-C5Me5)(μ-O)}3(XylNCNXyl)(CN)] (3) where the heterocumulene [XylNCCNXyl] moiety and the carbodiimido [NCNXyl] fragment in 2 have undergone net transformations. Similarly, tert-butyl isocyanide (tBuNC) reacts with the starting material 1 under mild conditions to give the paramagnetic derivative [{Ti3(η(5)-C5Me5)3(μ-O)3(NCNtBu)}2(μ-CN)2] (4). However, compound 1 provides the oxo ketimide derivatives [{Ti3(η(5)-C5Me5)3(μ-O)4}(NCRPh)] [R = Ph (5), p-Me(C6H4) (6), o-Me(C6H4) (7)] upon reaction with benzophenone, p-methylbenzophenone, and o-methylbenzophenone, respectively. In these reactions, the carbon-oxygen double bond is completely ruptured, leading to the formation of a carbon-nitrogen and two metal-oxygen bonds. The molecular structures of complexes 2-4, 6, and 7 were determined by single-crystal X-ray diffraction analyses. Density functional theory calculations were performed on the incorporation of isocyanides and ketones to the model complex [{Ti(η(5)-C5H5)(μ-O)}3(μ3-N)] (1H). The mechanism involves the coordination of the substrates to one of the titanium metal centers, followed by an isomerization to place those substrates cis with respect to the apical nitrogen of 1H, where carbon-nitrogen bond formation occurs with a low-energy barrier. In the case of aryl isocyanides, the resulting complex incorporates additional isocyanide molecules leading to a carbon-carbon coupling. With ketones, the high oxophilicity of titanium promotes the unusual total cleavage of the carbon-oxygen double bond.

show abstract

Section: Resultssupporting

confidence: 55%

Carbon–Nitrogen Bond Construction and Carbon–Oxygen Double Bond Cleavage on a Molecular Titanium Oxonitride: A Combined Experimental and Computational Study

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…[2a] The discovery of the bis(cyclopentadienyl)titanium-sulfur complex [Ti((η 5 -C 5 H 5 ) 2 S 5 ] by Samuel [10] and independently by Köpf and coworkers, [11] motivated the further development of systems structurally analogous to the related [(η 5 -C 5 Me 5 ) 2 Ti] species, such as mixed-cyclopentadienyl/aryloxide [12,13] or cyclopentadienyl/amidinate complexes. [14] Building upon our extensive studies about oxygen-containing titanium systems, [15] we have explored reactions aimed at the synthesis of sulfide derivatives of [(η 5 -C 5 Me 5 )Ti(IV)]. Thus, the systematic way to synthesize the chloro-derivative [Ti(η 5 -C 5 Me 5 )Cl(μ-S)] 2 from [Ti(η 5 -C 5 Me 5 )Cl 3 ] and Li 2 S has resulted in the isolation of a series of bimetallic complexes of the type [Ti(η 5 -C 5 Me 5 )R(μ-S)] 2 (R = alkyl, aryl or amide) comprising potential reactive MÀ C bonds.…”

Section: Introductionmentioning

confidence: 99%

Synthetic Studies and Structural Aspects of Dinuclear Sulfur Titanium Compounds

Álvarez‐Ruiz,

González‐Pérez,

Hernán‐Gómez

et al. 2024

Eur J Inorg Chem

Self Cite

View full text Add to dashboard Cite

A series of dinuclear sulfur‐bridged titanium derivatives [Ti(η5‐C5Me5)R(μ‐S)]2 (R = NMe2 (1), Ph (2), CH2Ph (3), CH2SiMe3 (4)) has been synthesized from the reaction of [Ti(η5‐C5Me5)Cl(μ‐S)]2 with the corresponding lithium salt or Grignard reagent. Formulation of 1‐4 as symmetric dimers has been confirmed by crystallographic studies. The analogous reaction with Mg(C3H5)Cl afforded the paramagnetic mixed‐valence Ti(III)/Ti(IV) compound [{Ti(η5‐C5Me5)(μ‐S)}2(μ‐C3H5)] (5). Contrasting with complexes 1‐4, compound 5 exhibits a bridging μ‐CH2CHCH2 fragment between the titanium atoms, which prevents the formation of a planar Ti2S2 core in the solid‐state structure. Complex 1 reacts with SiH3Ph to give [{Ti(η5‐C5Me5)(μ‐S)}2(μ‐NMe2)] (6), a paramagnetic mixed‐valence Ti(III)/Ti(IV) compound, structurally and electronically similar to 5. Under mild conditions, treatment of compounds 3 and 4 with H2 (1 atm) generates quantitatively the Ti(III) tetrametallic sulfide cluster [Ti(η5‐C5Me5)(μ3‐S)]4, along with the corresponding alkane.

show abstract

Construction of Titanasiloxanes by Incorporation of Silanols to the Metal Oxide Model [{Ti(η⁵‐C₅Me₅)(μ‐O)}₃(μ₃‐CR)]: DFT Elucidation of the Reaction Mechanism

Carbó

Moral

Martı́n

et al. 2008

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

A family of novel titanasiloxanes containing the structural unit ([Ti(eta 5-C5Me5)O]3) were synthesized by hydron-transfer processes involving reactions with equimolecular amounts of mu3-alkylidyne derivatives [(Ti(eta 5-C5Me5)(mu-O))(3)(mu3-CR)] (R=H (1), Me (2)) and monosilanols, R3'Si(OH), silanediols, R2'Si(OH)2, and the silanetriol tBuSi(OH)3. Treatment of 1 and 2 with triorganosilanols (R'=Ph, iPr) in hexane affords the new metallasiloxane derivatives [(Ti(eta 5-C5Me5)(mu-O))(3)(mu-CHR)(OSiR3')] (R=H, R'=Ph (3), iPr (4); R=Me, R'=Ph (5), iPr (6)). Analogous reactions with silanediols, (R'=Ph, iPr), give the cyclic titanasiloxanes [(Ti(eta 5-C5Me5)(mu-O))(3)(mu-O2SiR'2)(R)] (R=Me, R'=Ph (7), iPr (8); R=Et, R'=Ph (9), iPr (10)). Utilization of tBuSi(OH)3 with 1 or 2 at room temperature produces the intermediate complexes [(Ti(eta 5-C5Me5) (mu-O))(3)(mu-O2Si(OH)tBu)(R)] (R=Me (11), Et(12)). Further heating of solutions of 11 or 12 affords the same compound with an adamantanoid structure, [(Ti(eta 5-C5Me5)(mu-O))3(mu-O3SitBu)] (13) and methane or ethane elimination, respectively. The X-ray crystal structures of 3, 4, 6, 8, 10, 12, and 13 have been determined. To gain an insight into the mechanism of these reactions, DFT calculations have been performed on the incorporation of monosilanols to the model complex [(Ti(eta 5-C5H5)(mu-O))3(mu3-CMe)] (2 H). The proposed mechanism consists of three steps: 1) hydron transfer from the silanol to one of the oxygen atoms of the Ti3O3 ring, forming a titanasiloxane; 2) intramolecular hydron migration to the alkylidyne moiety; and 3) a mu-alkylidene ligand rotation to give the final product.

show abstract

Transfer Hydrogenation Processes toμ3-Alkylidyne Groups on the Organotitanium Oxide [Ti3CpO3]

Cited by 15 publications

References 60 publications

Carbon–Nitrogen Bond Construction and Carbon–Oxygen Double Bond Cleavage on a Molecular Titanium Oxonitride: A Combined Experimental and Computational Study

Carbon–Nitrogen Bond Construction and Carbon–Oxygen Double Bond Cleavage on a Molecular Titanium Oxonitride: A Combined Experimental and Computational Study

Synthetic Studies and Structural Aspects of Dinuclear Sulfur Titanium Compounds

Construction of Titanasiloxanes by Incorporation of Silanols to the Metal Oxide Model [{Ti(η⁵‐C₅Me₅)(μ‐O)}₃(μ₃‐CR)]: DFT Elucidation of the Reaction Mechanism

Contact Info

Product

Resources

About

Transfer Hydrogenation Processes toμ3-Alkylidyne Groups on the Organotitanium Oxide [Ti3CpO3]

Cited by 15 publications

References 60 publications

Carbon–Nitrogen Bond Construction and Carbon–Oxygen Double Bond Cleavage on a Molecular Titanium Oxonitride: A Combined Experimental and Computational Study

Carbon–Nitrogen Bond Construction and Carbon–Oxygen Double Bond Cleavage on a Molecular Titanium Oxonitride: A Combined Experimental and Computational Study

Synthetic Studies and Structural Aspects of Dinuclear Sulfur Titanium Compounds

Construction of Titanasiloxanes by Incorporation of Silanols to the Metal Oxide Model [{Ti(η5‐C5Me5)(μ‐O)}3(μ3‐CR)]: DFT Elucidation of the Reaction Mechanism

Contact Info

Product

Resources

About

Construction of Titanasiloxanes by Incorporation of Silanols to the Metal Oxide Model [{Ti(η⁵‐C₅Me₅)(μ‐O)}₃(μ₃‐CR)]: DFT Elucidation of the Reaction Mechanism