1124-18-1Relevant academic research and scientific papers
METAL-ASSISTED REACTIONS. PART 16. INVESTIGATION OF MECHANISMS OF HETEROGENEOUS LIQUID PHASE CATALYTIC TRANSFER HYDROGENOLYSIS THROUGH DEUTERIUM-LABELLING.
Johnstone, Robert A. W.,Price, Peter J.
, p. 2493 - 2502 (1985)
Hydrogen isotope studies have shown that heterogeneous catalytic transfer hydrogenolysis of C-O bonds in tetrazolyl ethers of phenols (1) in the liquid phase proceeds via direct transfer of hydrogen from an active hydrogen donor centre to the ether on the catalyst surface and not through transfer of hydrogen atoms from the catalyst surface.
Synthesis of group 13 element metallacarboranes and related structure-reactivity correlations
Schubert, David M.,Bandman, Marc A.,Rees Jr., William S.,Knobler, Carolyn B.,Lu, Paul,Nam, Wonwoo,Hawthorne, M. Frederick
, p. 2046 - 2061 (1990)
Synthesis, reactivity, and structural characterization studies of a number of group 13 metallacarborane species are described. These include studies of the icosahedral aluminacarborane closo-3-Et-3,1,2-AlC2B9H11 (1a). Compound 1a reacts with Lewis bases to form adducts of the type 2L-1a (L = Lewis base). The reaction of 1a with excess PEt3 results in the rapid formation of endo-10-{AlEt(PEt3)2}-7,8-C2B9H 11 (3). The novel sandwich species commo-3,3′-Al[{exo-8,9-(μ-H)2-AlEt 2-3,1,2-AlC2B9H9)}(3,1,2-AlC 2B9H11)] (4) results from thermal dimerization of 1a. The related sandwich anions [commo-3,3′-Al(3,1,2-AlC2B9H11) 2]- ([5]-) and [commo-3,3′-Ga(3,1,2-GaC2B9H11) 2]- ([6]-) have been prepared. The full details of the synthesis and structural characterization of σ-bonded species nido-6,9-(μ-AlEt-(OEt2))-6,9-C2B8H 10 (8), [Al(η2-6,9-C2B8H10) 2]- ([10]-), and [Al(η2-2,7-C2B6H8) 2]- ([11]-) are reported. The metallacarboranes 3, 4, [5]-, [6]-, 8, [10]-, and [11]- were characterized by a combination of spectroscopic techniques and by single-crystal X-ray diffraction studies. Crystallographic parameters are as follows: 3, P21/n, a = 9.722 (3) A?, b = 16.135 (4) A?, c = 16.984 (5) A?, β = 90.246 (9)°, V = 2652 A?3, Z = 4, R = 0.064, Rw = 0.082 for 3394 independent reflections with I > 3σ(I); 4, P21/n, a = 7.122 (2) A?, b = 27.668 (8) A?, c = 11.629 (3) A?, β = 96.246 (5)°, V = 2288 A?3, Z = 4, R = 0.065, Rw = 0.075, GOF = 2.39 for 2137 independent reflections; Tl[5]·2/3C7H8, P1, a = 11.347 (2) A?, b = 11.748 (2) A?, c = 12.708 (2) A?, α = 92.429 (6)°, β = 90.876 (6)°, γ = 93.343 (5)°, V = 1689 A?3, Z = 3, R = 0.057, Rw = 0.064, GOF = 1.57 for 1941 independent reflections; Tl[6], P1, a = 6.9564 (6) A?, b = 11.0466 (9) A?, c = 12.0287 (10) A?, α = 102.088 (2)°, β = 95.484 (2)°, γ = 94.687 (3)°, V = 894 A?3, Z = 2, R = 0.041, Rw, = 0.054, GOF = 2.03 for 2733 independent reflections; 8·1/2C6H6, A1, a = 13.964 (3) A?, b = 15.966 (4) A?, c = 8.550 (2) A?, α = 92.227 (8)°, β = 86.689 (7)°, γ = 102.060 (8)°, V = 1862 A?3, Z = 4 (reduced cell: a = 8.552 A?, b = 8.909 A?, c = 13.967 A?, α = 99.172°, β = 93.323°, γ = 116.428°, V = 930.9 A?3, Z = 2) R = 0.061, Rw = 0.081, GOF = 2.85 for 2338 independent reflections; [(PPh3)2N][10], P21/c, a = 16.378 (3) A?, b = 18.781 (3) A?, c = 14.806 (3) A?, β = 90.197 (5)°, V = 4554 A?3, Z = 4, R = 0.078, Rw = 0.088, GOF = 2.0 for 2128 independent reflections; [Na][11], P21, a = 10.035 (2) A?, b = 12.433 (3) A?, c = 11.690 (3) A?, β = 111.019 (7)°, V = 1367 A?3, Z = 4, R = 0.049, Rw = 0.059, GOF = 2.08 for 2156 independent reflections. The compound Tl[5]°2/3C7H8 contains the thallium(I)-arene complex Tl(η6-MePh). Compounds 1a and 4 were shown to catalyze the exchange of carborane B-H and arene C-D bonds as well as the polymerization of selected olefins under mild homogeneous conditions. Bonding and the varying degrees of distortion from idealized closo and commo geometries displayed by 3,4, [5]-, and [6]- are discussed. Species 8, [10]-, and [11]- contain Al-C σ-bonded aluminum-carborane connectivities. Compound 8 exhibits rapid exchange of aluminum-coordinated ether in solution, and the compound nido-6,9-(μ-AlEt-(C4H8O))-6,9-C2B 8H10 (9) was prepared by ether exchange of 8 in tetrahydrofuran/toluene. Anion [11]-undergoes rapid enantiomer interconversion in solution at room temperature.
Direct Use of Benzylic Alcohols for Multicomponent Synthesis of 2-Aryl Quinazolinones Utilizing the π-Benzylpalladium(II) System in Water
Hikawa, Hidemasa,Nakayama, Taku,Takahashi, Makiko,Kikkawa, Shoko,Azumaya, Isao
supporting information, p. 4075 - 4084 (2021/07/26)
We demonstrate the direct use of benzylic alcohols for a multicomponent reaction of readily available isatoic anhydrides with amines in water, which is a synthetic route for the direct construction of a series of 2-aryl quinazolinones. This one-pot synthetic method involves the dehydrative N-benzylation of in situ generated anthranilamides followed by an amide-directed benzylic C?H amination process utilizing the π-benzylPd(II) system. Comparison of independent rate measurements using benzyl alcohol and its deuterated form gave a kinetic isotope effect of 3.5. Therefore, the benzylic C?H bond is cleaved in the rate-determining step. We successfully carried out a gram-scale reaction in 85% yield with simplified product isolation. (Figure presented.).
Hydrogenation of Benzonitrile over Supported Pd Catalysts: Kinetic and Mechanistic Insight
McAllister, Mairi I.,Boulho, Cédric,Gilpin, Lauren F.,McMillan, Liam,Brennan, Colin,Lennon, David
, p. 977 - 989 (2019/04/25)
The liquid phase hydrogenation of benzonitrile over a 5 wt % Pd/C catalyst using a stirred autoclave is investigated. The reaction conforms to a consecutive reaction sequence: first benzonitrile is hydrogenated to produce benzylamine, which subsequently u
Method for catalytic conversion of cyano group into deuterated methyl, prepared aromatic deuterated methyl compound and application of compound
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Paragraph 0094; 0095; 0096; 0097; 0098; 0099, (2017/12/09)
The invention provides a method for catalytic conversion of a cyano group into deuterated methyl, a prepared aromatic deuterated methyl compound and an application of the compound. The method comprises the steps as follows: an aromatic cyano compound reacts to produce the aromatic deuterated methyl compound under the action of a metal catalyst with deuterium gas serving as a deuterium source. The cyano group is directly catalyzed into deuterated methyl with the deuterium gas serving as the deuterium source, the operation is simple, the raw material is cheap and easy to obtain, the reaction yield is high, the product deuteration rate is high, and the method can be applied to mass production. The prepared aromatic deuterated methyl compound can be used as a deuterated medicine or can be used for preparation of a deuterated medicine or deuterated medicine composition, and the pharmacokinetics, pharmacodynamics or metabolism toxicity of the medicine can be reduced while the medicine molecular activity is kept unchanged basically.
Mechanistic Investigation of Molybdate-Catalysed Transfer Hydrodeoxygenation
Larsen, Daniel B.,Petersen, Allan R.,Dethlefsen, Johannes R.,Teshome, Ayele,Fristrup, Peter
supporting information, p. 16621 - 16631 (2016/11/09)
The molybdate-catalysed transfer hydrodeoxygenation (HDO) of benzyl alcohol to toluene driven by oxidation of the solvent isopropyl alcohol to acetone has been investigated by using a combination of experimental and computational methods. A Hammett study that compared the relative rates for the transfer HDO of five para-substituted benzylic alcohols was carried out. Density-functional theory (DFT) calculations suggest a transition state with significant loss of aromaticity contributes to the lack of linearity observed in the Hammett study. The transfer HDO could also be carried out in neat PhCH2OH at 175 °C. Under these conditions, PhCH2OH underwent disproportionation to yield benzaldehyde, toluene, and significant amounts of bibenzyl. Isotopic-labelling experiments (using PhCH2OD and PhCD2OH) showed that incorporation of deuterium into the resultant toluene originated from the α position of benzyl alcohol, which is in line with the mechanism suggested by the DFT study.
N-benzylation/benzylic C-H amidation cascade by the (ζ3- Benzyl)palladium system in aqueous media: An effective pathway for the direct construction of 3-phenyl-3,4-dihydro-(2H)-1,2,4-benzothiadiazine 1,1-dioxides
Hikawa, Hidemasa,Matsuda, Naoya,Suzuki, Hideharu,Yokoyama, Yuusaku,Azumaya, Isao
supporting information, p. 2308 - 2320 (2013/10/01)
We demonstrate a unique strategy for a benzylation/benzylic C-H amidation cascade reaction by the (ζ3-benzyl)palladium system derived from a palladium catalyst and benzyl alcohol. This tandem process is devised as a new synthetic route for 3-phenyl-3,4-dihydro-(2H)-1,2,4-benzothiadiazine-1,1- dioxide. Water plays an important role for the smooth generation of the (ζ3-benzyl)palladium species, and a bis-benzylated Pd(II) intermediate would be formed in our catalytic system. Atom economical processes such as benzylic C-H activation, cascade reactions and chemoselective reactions in aqueous media have been developed.
Pd-catalyzed benzylic C-H amidation with benzyl alcohols in water: A strategy to construct quinazolinones
Hikawa, Hidemasa,Ino, Yukari,Suzuki, Hideharu,Yokoyama, Yuusaku
, p. 7046 - 7051 (2012/10/07)
A novel method for the synthesis of 4-phenylquinazolinones via a palladium-catalyzed domino reaction of o-aminobenzamides with benzyl alcohols is developed. This protocol involves N-benzylation, benzylic C-H amidation, and dehydrogenation in water, which may play an important role in the smooth generation of the (η3-benzyl)palladium species by activation of the hydroxyl group of the benzyl alcohol.
Primary and Secondary Kinetic Deuterium Isotope Effects and Transition-State Structures for Benzylic Chlorination and Bromination of Toluene
Hanzlik, Robert P.,Schaefer, Angela R.,Moon, Joseph B.,Judson, Charles M.
, p. 4926 - 4930 (2007/10/02)
As a chemical model for benzylic hydroxylations effected by cytochrome P-450 enzymes, the chlorination of PhCH3, PhCH2D, PhCHD2, and PhCD3 in a two-phase system of hypochlorite/CH2Cl2 with a phase-transfer catalyst has been investigated.On the basis of th
