4920-92-7Relevant articles and documents
Remarkably Efficient Iridium Catalysts for Directed C(sp2)-H and C(sp3)-H Borylation of Diverse Classes of Substrates
Chattopadhyay, Buddhadeb,Hassan, Mirja Md Mahamudul,Hoque, Md Emdadul
supporting information, p. 5022 - 5037 (2021/05/04)
Here we describe the discovery of a new class of C-H borylation catalysts and their use for regioselective C-H borylation of aromatic, heteroaromatic, and aliphatic systems. The new catalysts have Ir-C(thienyl) or Ir-C(furyl) anionic ligands instead of the diamine-type neutral chelating ligands used in the standard C-H borylation conditions. It is reported that the employment of these newly discovered catalysts show excellent reactivity and ortho-selectivity for diverse classes of aromatic substrates with high isolated yields. Moreover, the catalysts proved to be efficient for a wide number of aliphatic substrates for selective C(sp3)-H bond borylations. Heterocyclic molecules are selectively borylated using the inherently elevated reactivity of the C-H bonds. A number of late-stage C-H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)-H and C(sp3)-H borylations enabling the method more general. Preliminary mechanistic studies suggest that the active catalytic intermediate is the Ir(bis)boryl complex, and the attached ligand acts as bidentate ligand. Collectively, this study underlines the discovery of new class of C-H borylation catalysts that should find wide application in the context of C-H functionalization chemistry.
Nickel-Catalyzed Photodehalogenation of Aryl Bromides
Higginson, Bradley,Sanjosé-Orduna, Jesus,Gu, Yiting,Martin, Ruben
supporting information, p. 1633 - 1636 (2021/04/23)
Herein, we describe a Ni-catalyzed photodehalogenation of aryl bromides under visible-light irradiation that utilizes tetrahydrofuran as hydrogen source. The protocol obviates the need for exogeneous amine reductants or photocatalysts and is characterized by its simplicity and broad scope, including challenging substrate combinations.
Regioselective Ortho‐C–H sulfenylation of free phenols catalyzed by Co(II)-immobilized on silica-coated magnetic nanoparticles
Khaef, Sepideh,Rostami, Abed,Khakyzadeh, Vahid,Zolfigol, Mohammad Ali,Taherpour, Avat Arman,Yarie, Meysam
, (2020/01/22)
Fe3O4?SiO2-UT?CoII is prepared by the silica-coated magnetic nanoparticles, urea-triazole, and CoCl2. This organic-inorganic hybride composite showed a good to excellent catalytic activity toward regioselective ortho-sulfenylation of free phenols and naphthols using pivalic anhydride as a directing group, also K2S2O8 and PPh3 were employed as oxidant and additive respectively. The newly synthesized catalyst was fully characterized by using different techniques such as FT-IR, TGA, DTG, TEM, SEM, EDS, ICP and VSM analyses. The competitive price, accessibility and lower toxicity of cobalt compared to expensive transition metals using for C–H bond activation and functionalization constitute precious advantages for this method. Moreover, this heterogeneous catalyst could be magnetically recovered and reused without significant loss of its catalytic activity after five cycles.
Styrene Production from Benzene and Ethylene Catalyzed by Palladium(II): Enhancement of Selectivity toward Styrene via Temperature-dependent Vinyl Ester Consumption
Jia, Xiaofan,Foley, Aisling M.,Liu, Chang,Vaughan, Benjamin A.,McKeown, Bradley A.,Zhang, Sen,Gunnoe, T. Brent
supporting information, p. 3532 - 3541 (2019/09/12)
Oxidative ethylene hydrophenylation catalyzed by palladium(II) acetate with Cu(II) oxidants to produce styrene generally suffers from low selectivity and/or low yield. Commonly observed side products include vinyl carboxylates and stilbene. In this Article, the selectivity for styrene formation by Pd(OAc)2 is studied as a function of reaction temperature, ethylene pressure, Br?nsted acid additive, Cu(II) oxidant amount, and oxygen pressure. Under optimized conditions, at high temperatures (180 °C) and low olefin pressure (20 psig), nearly quantitative yield (>95%) of styrene is produced based on the limiting reagent copper(II) pivalate. We propose the selectivity for styrene versus vinyl pivalate at 180 °C is due to a palladium-catalyzed conversion of benzene and in situ formed vinyl pivalate to styrene.
Palladium-Catalyzed Aerobic Oxidative Coupling of Amides with Arylboronic Acids by Cooperative Catalysis
Li, Yue,Wu, Hongxiang,Zeng, Zhuo
, p. 4357 - 4361 (2019/07/09)
The first fluoride and palladium co-catalyzed conversion of amide to ester through an aerobic oxidative coupling pathway is reported. This new approach presents a practical process that employs easily available oxygen and commercially available arylboronic acids as coupling partners, uses a wide range of N- tosylamides, and proceeds under mild reaction conditions. This protocol demonstrates broad functional group tolerance, and provides an alternative option to synthesize esters from N-tosylamides which obtained by simply N-functionalization of secondary amides.
Double - (to - alkoxybenzyl propenone) glutathione - S - transfers the sulfur of the enzyme dives inhibitors
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Paragraph 0038; 0072; 0073; 0075, (2020/05/08)
The invention discloses a bis-(p-alkoxy benzene acrylketone) like glutathione-S-transferase potential inhibitor. Structure and living features of the potential inhibitor are as follows: two p-alkoxy benzene acrylketone units are linked to two amino groups, alcoholic hydroxyl groups and carboxyl groups or one amino group and one alcoholic hydroxyl group which are spaced by less than 8 single bonds through amide and/or ester bond, wherein compounds obtained are substrate and inhibitor of glutathione-S-transferase, namely GST; the GST catalyzes carbon-carbon bond and reduced glutathione, namely GSH, of alpha, beta-unsaturated ketone of each p-alkoxy benzene acrylketone unit in the compounds and generates a compound, namely product, through Michael addition. The product shows a stronger inhibiting efficacy on the GST, so that the compound is a GST potential inhibitor; the product has a stronger inhibiting efficacy on human GST isozyme mu in comparison with human GST isozyme alpha and pi; and the compounds can enter into cells, and can enhance inhibiting effect of cis-platinum on drug-resistant carcinoma cell growth.
Transition-Metal-Free Esterification of Amides via Selective N-C Cleavage under Mild Conditions
Li, Guangchen,Lei, Peng,Szostak, Michal
supporting information, p. 5622 - 5625 (2018/09/25)
A general, transition-metal-free, and operationally simple method for esterification of amides by a highly selective cleavage of N-C(O) bonds under exceedingly mild conditions is reported. The reaction is characterized by broad substrate scope and excellent functional group tolerance. The potential of this mild esterification is highlighted by late-stage diversification of natural products and pharmaceuticals. Conceptually, the metal-free acyl functionalization of amides represents a significant step forward as a practical alternative to ligand exchange in acylmetal intermediates.
CARBOXYLIC ACID ESTER PRODUCTION METHOD
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Paragraph 0075; 0076, (2019/01/04)
Provided is a production method whereby corresponding carboxylic acid esters can be obtained from a variety of carboxylic acids at a high yield, even under conditions using a simple reaction operation and little catalyst and even if the amount of substrate used is theoretical. A production method for carboxylic acid ester, whereby a prescribed diester dicarbonate, carboxylic acid, and alcohol are reacted in the presence of at least one type of magnesium compound and at least one type of alkali metal compound.
Ni-Catalyzed Stannylation of Aryl Esters via C?O Bond Cleavage
Gu, Yiting,Martín, Rúben
supporting information, p. 3187 - 3190 (2017/03/17)
A Ni-catalyzed stannylation of aryl esters with air- and moisture-insensitive silylstannyl reagents via Csp2 ?O cleavage is described. This protocol is characterized by its wide scope, including challenging combinations, thus enabling access to versatile building blocks and orthogonal C?heteroatom bond formations.
Iodobenzene Dichloride in the Esterification and Amidation of Carboxylic Acids: In-Situ Synthesis of Ph3PCl2
Carle, Myriam S.,Shimokura, Grace K.,Murphy, Graham K.
supporting information, p. 3930 - 3933 (2016/08/24)
A novel, in-situ synthesis of dichlorotriphenylphosphorane (Ph3PCl2) is accomplished upon combining PPh3and the easily prepared hypervalent iodine reagent iodobenzene dichloride (PhICl2). The phosphorane is selectively generated in the presence of carboxylic acid or alcohol residues to rapidly produce acyl chlorides and alkyl chlorides in high yields. Addition of EtOH, PhOH, BnOH, Et2NH or CH2N2results in the direct synthesis of esters, amides and diazo ketones from carboxylic acids.
