Asymmetric Darzens Reaction of Isatins with Diazoacetamides Catalyzed by Chiral BINOL–Titanium Complex

2017 ◽  
Vol 82 (23) ◽  
pp. 12647-12654 ◽  
Author(s):  
Guo-Li Chai ◽  
Jian-Wei Han ◽  
Henry N. C. Wong
Keyword(s):  
Darzens Reaction ◽  
Titanium Complex

Reversible Oxidative-Addition and Reductive-Elimination of Thiophene from a Titanium Complex and Its Thermally-Induced Hydrodesulfurization Chemistry

2019 ◽  
Author(s):  
Alejandra Gomez-Torres ◽  
J. Rolando Aguilar-Calderón ◽  
Carlos Saucedo ◽  
Aldo Jordan ◽  
Alejandro J. Metta-Magaña ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Ring Opening ◽  
Thiophene Ring ◽  
Oxidative Addition ◽  
Reductive Elimination ◽  
Thermally Induced ◽  
Titanium Complex

<p>The masked Ti(II) synthon (<sup>Ket</sup>guan)(<i>η</i><sup>6</sup>-Im<sup>Dipp</sup>N)Ti (<b>1</b>) oxidatively adds across thiophene to give ring-opened (<sup>Ket</sup>guan)(Im<sup>Dipp</sup>N)Ti[<i>κ</i><sup>2</sup>-<i>S</i>(CH)<sub>3</sub><i>C</i>H] (<b>2</b>). Complex <b>2</b> is photosensitive, and upon exposure to light, reductively eliminates thiophene to regenerate <b>1</b> – a rare example of early-metal mediated oxidative-addition/reductive-elimination chemistry. DFT calculations indicate strong titanium π-backdonation to the thiophene π*-orbitals leads to the observed thiophene ring opening across titanium, while a proposed photoinduced LMCT promotes the reverse thiophene elimination from <b>2</b>. Finally, pressurizing solutions of <b>2 </b>with H<sub>2</sub> (150 psi) at 80 °C leads to the hydrodesulfurization of thiophene to give the Ti(IV) sulfide (<sup>Ket</sup>guan)(Im<sup>Dipp</sup>N)Ti(S) (<b>3</b>) and butane. </p>

The synthesis and structure of silica-supported bis(h5-cyclopentadienyl)dichlorotitanium(IV) complexes

1986 ◽  
Vol 51 (7) ◽  
pp. 1430-1438 ◽  
Author(s):  
Alena Reissová ◽  
Zdeněk Bastl ◽  
Martin Čapka
Keyword(s):  
Free Surface ◽  
Hydroxyl Groups ◽  
Titanium Complex ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
Free Hydroxyl ◽  
Cyclopentadienyl Anion

The title complexes have been obtained by functionalization of silica with cyclopentadienylsilanes of the type Rx(CH3)3 - xSi(CH2)nC5H5 (x = 1-3, n = 0, 1, 3), trimethylsilylation of free surface hydroxyl groups, transformation of the bonded cyclopentadienyl group to the cyclopentadienyl anion, followed by coordination of (h5-cyclopentadienyl)trichlorotitanium. The effects of single steps of the above immobilization on texture of the support, the number of free hydroxyl groups, the coverage of the surface by cyclopentadienyl groups and the degree of their utilization in anchoring the titanium complex have been investigated. ESCA study has shown that the above anchoring leads to formation of the silica-supported bis(h5-cyclopentadienyl)dichlorotitanium(IV) complex.

Synthesis of amino alcohols on solid support via sulfonium-ion mediated Darzens reaction

2001 ◽  
Vol 42 (30) ◽  
pp. 5127-5130 ◽  
Author(s):  
Bernd Peschke ◽  
Joan Gredal Bundgaard ◽  
Jens Breinholt
Keyword(s):  
Amino Alcohols ◽  
Solid Support ◽  
Darzens Reaction

Highly Diastereoselective and Irreversible Aldol Reactions of N-Sulfonylimidates

Synthesis ◽  
2016 ◽  
Vol 48 (19) ◽  
pp. 3413-3419 ◽  
Author(s):  
Hannah Bartrum ◽  
Sébastien Carret ◽  
Jean-François Poisson
Keyword(s):  
Lewis Acid ◽  
High Yield ◽  
Aldol Reactions ◽  
Titanium Complex ◽  
Reaction Proceeds

A mild method for the aldolization of N-sulfonylimidates was developed. The reaction proceeds in excellent diastereoselectivity to provide a range of useful β-hydroxyimidates in high yield. The innate reversibility of the reaction is suppressed by the use of a titanium complex as a Lewis acid.

ChemInform Abstract: Asymmetric Synthesis of Trisubstituted Aziridines via Aza-Darzens Reaction of Chiral Sulfinimines.

ChemInform ◽  
2015 ◽  
Vol 46 (23) ◽  
pp. no-no
Author(s):  
Toni Moragas ◽  
Ian Churcher ◽  
William Lewis ◽  
Robert A. Stockman
Keyword(s):  
Asymmetric Synthesis ◽  
Darzens Reaction

scholarly journals Pinacol Coupling of Aromatic Aldehydes using La-Ticl4in CH3COOEt under Ultrasound Irradiation

2006 ◽  
Vol 3 (4) ◽  
pp. 230-235
Author(s):  
Ji-Tai Li ◽  
Xue-Li Sun ◽  
Zhi-Ping Lin ◽  
Tong-Shuang Li
Keyword(s):  
Ethyl Acetate ◽  
Titanium Tetrachloride ◽  
Aromatic Aldehydes ◽  
Ultrasound Irradiation ◽  
Titanium Complex ◽  
Pinacol Coupling ◽  
Low Valent

Titanium tetrachloride can be reduced by lanthanum filings to the corresponding low valent titanium complex, which can induce some aromatic aldehydes to the corresponding pinacols in 28%-97% yields within 10-50 min in ethyl acetate at r.t. under ultrasound irradiation.

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