346-06-5Relevant academic research and scientific papers
Structural Elucidation of Silver(I) Amides and Their Application as Catalysts in the Hydrosilylation and Hydroboration of Carbonyls
Blair, Victoria L.,Boutland, Aaron J.,Kelly, John A.,Orr, Samantha A.
supporting information, p. 4947 - 4951 (2020/04/22)
This study details the isolation and characterisation of three novel silver(I) amides in solution and solid-state, [Ag(Cy3P)(HMDS)] 2, [Ag(Cy3P){N(TMS)(Dipp)}] 3 and [Ag(Cy3P)2(NPh2)] 4. Their catalytic abilities have proved successful in hydroboration and hydrosilylation reactions with a full investigation performed with complex 2. Both protocols proceed under mild conditions, displaying exceptional functional-group tolerance and chemoselectivity, in excellent conversions at competitive reaction times. This work reveals the first catalytic hydroboration of aldehydes and ketones performed by a silver(I) catalyst.
Cerium(IV) Carboxylate Photocatalyst for Catalytic Radical Formation from Carboxylic Acids: Decarboxylative Oxygenation of Aliphatic Carboxylic Acids and Lactonization of Aromatic Carboxylic Acids
Hirosawa, Keishi,Mashima, Kazushi,Satoh, Tetsuya,Shinohara, Koichi,Shirase, Satoru,Tamaki, Sota,Tsurugi, Hayato
supporting information, (2020/03/25)
We found that in situ generated cerium(IV) carboxylate generated by mixing the precursor Ce(OtBu)4 with the corresponding carboxylic acids served as efficient photocatalysts for the direct formation of carboxyl radicals from carboxylic acids under blue light-emitting diodes (blue LEDs) irradiation and air, resulting in catalytic decarboxylative oxygenation of aliphatic carboxylic acids to give C-O bond-forming products such as aldehydes and ketones. Control experiments revealed that hexanuclear Ce(IV) carboxylate clusters initially formed in the reaction mixture and the ligand-to-metal charge transfer nature of the Ce(IV) carboxylate clusters was responsible for the high catalytic performance to transform the carboxylate ligands to the carboxyl radical. In addition, the Ce(IV) carboxylate cluster catalyzed direct lactonization of 2-isopropylbenzoic acid to produce the corresponding peroxy lactone and ?3-lactone via intramolecular 1,5-hydrogen atom transfer (1,5-HAT).
Polypyridyl iridium(III) based catalysts for highly chemoselective hydrogenation of aldehydes
Pandrala, Mallesh,Resendez, Angel,Malhotra, Sanjay V.
, p. 283 - 288 (2019/09/30)
Iridium-catalyzed transfer hydrogenation (TH) of carbonyl compounds using HCOOR (R = H, Na, NH4) as a hydrogen source is a pivotal process as it provides the clean process and is easy to execute. However, the existing highly efficient iridium catalysts work at a narrow pH; thus, does not apply to a wide variety of substrates. Therefore, the development of a new catalyst which works at a broad pH range is essential as it can gain a broader scope of utilization. Here we report highly efficient polypyridyl iridium(III) catalysts, [Ir(tpy)(L)Cl](PF6)2 {where tpy = 2,2′:6′,2′'-Terpyridine, L = phen (1,10-Phenanthroline), Me2phen (4,7-Dimethyl-1,10-phenanthroline), Me4phen (3,4,7,8-Tetramethyl-1,10-phenanthroline), Me2bpy (4,4′-Dimethyl-2–2′-dipyridyl)} for the chemoselective reduction of aldehydes to alcohols in aqueous ethanol and sodium formate as the hydride source. The reaction can be carried out efficiently in broad pH ranges, from pH 6 to 11. These catalysts are air stable, easy to prepare using commercially available starting materials, and are highly applicable for a wide range of substrates, such as electron-rich or deficient (hetero)arenes, halogens, phenols, alkoxy, ketones, esters, carboxylic acids, cyano, and nitro groups. Particularly, acid and hydroxy groups containing aldehydes were reduced successfully in basic and acidic reaction conditions, demonstrating the efficiency of the catalyst in a broad pH range with high conversion rates under microwave irradiation.
A Pseudodearomatized PN3P?Ni-H Complex as a Ligand and σ-Nucleophilic Catalyst
Li, Huaifeng,Gon?alves, Théo P.,Hu, Jinsong,Zhao, Qianyi,Gong, Dirong,Lai, Zhiping,Wang, Zhixiang,Zheng, Junrong,Huang, Kuo-Wei
, p. 14969 - 14977 (2019/01/03)
In contrast to the conventional strategy of modifying the reactivities and selectivities of the transition metal and organocatalysts by varying the steric and electronic properties of organic substituent groups, we hereby demonstrate a novel approach that the sigma (σ) nucleophilicity of the imine arm can be significantly enhanced in a pseudodearomatized PN3P? pincer ligand platform to reach unprecedented N-heterocyclic carbene-like reactivity. Accordingly, the imine arm of the PN3P?Ni-H pincer complex efficiently catalyzes the hydrosilylation of aldehydes, cycloaddition of carbon dioxide (CO2) to epoxides, and serves as a ligand in the Ru-catalyzed dehydrogenative acylation of amines with alcohols.
Cooperative interplay between a flexible PNN-Ru(II) complex and a NaBH4 additive in the efficient catalytic hydrogenation of esters
Wang, Zheng,Chen, Xiangyang,Liu, Bo,Liu, Qing-Bin,Solan, Gregory A.,Yang, Xinzheng,Sun, Wen-Hua
, p. 1297 - 1304 (2017/05/05)
A catalyst loading of between 0.001-0.05 mol% of the PNN-bearing ruthenium(II) complex [fac-PNN]RuH(PPh3)(CO) (PNN = 8-(2-diphenylphosphinoethyl)amidotrihydroquinoline), in combination with 5 mol% NaBH4, efficiently catalyzes the hydrogenation of esters to their corresponding alcohols under mild pressures of hydrogen. Both aromatic and aliphatic esters can be converted with high values of TON or TOF achievable. Mechanistic investigations using both DFT calculations and labeling experiments highlight the cooperative role of NaBH4 in the catalysis while the catalytically active species has been established as trans-dihydride [mer-PNHN]RuH2(CO) (PNHN = 8-(2-diphenylphosphinoethyl)aminotrihydroquinoline). The stereo-structure of the PNHN-ruthenium species greatly affects the activity of the catalyst, and indeed the cis-dihydride isomer [fac-PNHN]RuH2(CO) is unable to catalyze the hydrogenation of esters until ligand reorganization occurs to give the trans isomer.
Preparation method of 2-methyl-5-aminotrifluorotoluene
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Paragraph 0047; 0048, (2017/06/24)
The invention provides a preparation method of 2-methyl-5-aminotrifluorotoluene. The method comprises the following steps: reducing 2-trifluoromethylbenzaldehyde, serving as a raw material, with sodium borohydride to obtain 2-trifluoromethyl benzyl alcohol; performing chlorination by sulfoxide chloride to obtain 2-trifluoromethyl benzyl chloride; nitrifying to obtain 2-chloromethyl-5-nitryltrifluorotoluene; lastly, performing hydrogenation reduction to obtain a target product, namely, 2-methyl-5-aminotrifluorotoluene. The method has the advantages of easiness in operation, high product yield, low cost and easiness in industrialization. The chemical formula of the 2-methyl-5-aminotrifluorotoluene is shown in the description.
Benzamide compounds containing acetenyl group
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Paragraph 0066; 0067, (2017/07/22)
The invention provides acetenyl group-containing benzamide compounds as shown in a formula (I) and used for treating or preventing diseases related to protein kinase, and medicinal salts or configurational isomers thereof. A connection group L, a ring A and substituents R, R, R, R and R in the formula (I) are as defined in the specification. The invention also discloses a preparation method and a pharmaceutical composition of the compounds as shown in the formula (I), and application of the compounds to preparation or prevention of drugs used for preventing diseases related to protein kinase.
Metal- and O2-Free Oxidative C-C Bond Cleavage of Aromatic Aldehydes
Hu, Guang,Ramakumar, Kinthada,Brenner-Moyer, Stacey E.
, p. 6972 - 6977 (2017/07/17)
An oxidative C-C cleavage of aldehydes requiring neither metals nor O2 was discovered. Homobenzylic aldehydes and α-substituted homobenzylic aldehydes were cleaved to benzylic aldehydes and ketones, respectively, using nitrosobenzene as an oxidant. This reaction is chemoselective for aromatic aldehydes, as an aliphatic aldehyde was unreactive under these conditions, and other reactive functionality such as ketones and free alcohols are tolerated. A mechanism accounting for the fate of the lost carbon is proposed.
Method for preparing alcohol through catalytic hydrogenation reduction of carboxylate
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Paragraph 0023; 0024; 0040, (2016/12/07)
The invention discloses a method for preparing alcohol through catalytic hydrogenation reduction of a carboxylate compound with 2-(diphenylphosphinoethyl)-(5,6,7,8-tetrahydroquinolyl)amine as a ruthenium complex catalyst of ligand. The catalyst has high-efficiency catalysis activity on alkyl benzoate, aromatic esters and fatty esters. The preparation method is simple and has good stability, the catalysis activity of the catalyst is high, and the dosage of the catalyst is 0.025-0.005% of the mole of a substrate. The method can be used for producing alcohols, and has the advantages of simplicity, small pollution to environment, high yield and low cost. Most of carboxylate can be hydrogenated and reduced to form alcohols by using a complex represented by formula (1) with sodium borohydride as an additive, and the conversion number TOC can reach 50000; and a cocaalyst sodium borohydride is used to substitute most of alcoholic alkalis used as a catalyst in especially used in aromatic esters with electron-withdrawing substituent, so the cost is reduced, operation is simple, and industrial production is easy.
The design of a readily attachable and cleavable molecular scaffold for ortho-selective C-H alkenylation of arene alcohols
Knight, Brian J.,Rothbaum, Jacob O.,Ferreira, Eric M.
, p. 1982 - 1987 (2016/03/05)
We describe herein the design of a novel molecular scaffold that can induce facile oxidative olefinations when attached to alcohols. Benzylic, homo-, and bishomobenzylic alcohols are utilized. The scaffold can act as a protecting group for the alcohol in other transformations, and it is recoverable in excellent yield. The overall sequence can also be telescoped without purifications of intermediates, representing a net alcohol-based directed ortho-alkenylation.
