274-09-9Relevant articles and documents
Cobalt-catalyzed addition of arylzinc reagents to norbornene derivatives through 1,4-cobalt migration
Tan, Boon-Hong,Yoshikai, Naohiko
, p. 3392 - 3395 (2014)
A cobalt-diphosphine catalyst promotes the addition of an arylzinc reagent to a norbornene derivative to afford o-(2-exo-norbornyl)arylzinc species. This migratory arylzincation reaction is considered to involve insertion of norbornene into an arylcobalt species, alkyl-to-aryl 1,4-cobalt migration, and transmetalation between the resulting o-(2-exo-norbornyl)arylcobalt species and the arylzinc reagent. The o-(2-exo-norbornyl)arylzinc species can be intercepted by common organic electrophiles under copper or palladium catalysis.
Transition metal catalyzed preparation of Grignard compounds
Bogdanovi, Borislav,Schwickardi, Manfred
, p. 4610 - 4612 (2000)
The "inorganic Grignard reagents", in particular those of 1, have surprisingly been shown to be efficient homogeneous catalysts for the conversion of inactive chloroarenes and heteroarenes (via the aryl-iron intermediate 2) into the corresponding Grignard
Efficient base-free hydrodehalogenation of organic halides catalyzed by a well-defined diphosphine-ruthenium(II) complex
Gao, Pengxiang,Liu, Qingbin,Liu, Yahuan,Ma, Ning,Wang, Zheng,Zhao, Ziwei
, (2021/10/29)
A base-free, robust catalytic system based on the diphosphine-ruthenium(II) complex cation has been developed for the hydrodehalogenation of a wide range of aryl- and alkyl-chlorides/bromides (27 examples) with molecule hydrogen. Notably, the reaction proceeds at 120 °C with low catalyst loading (0.1 mol%) and exhibits a good tolerance toward functional groups, such as amido, carboxyl, sulfonyl, methoxyl, ester groups. All dehalogenation products are confirmed by GC, GC–MS and NMR spectroscopy. Moreover, a mechanism for the diphosphine-ruthenium(II) complex cation catalyzed dehalogenation process has been proposed. This hydrodehalogenation methodology shows a potential application for the organic transformation and degradation of organic halides.
Mechanistic studies into visible light-driven carboxylation of aryl halides/triflates by the combined use of palladium and photoredox catalysts
Caner, Joaquim,Iwasawa, Nobuharu,Martin, Ruben,Murata, Kei,Shimomaki, Katsuya,Toriumi, Naoyuki
supporting information, p. 1846 - 1853 (2021/08/13)
The reaction mechanism of palladium-catalyzed visible light-driven carboxylation of aryl halides and triflates with a photoredox catalyst was examined in detail. Experimental and theoretical studies indicated that the active species for photoredox- catalyzed reduction was cationic ArPd(II)+ species to generate nucleophilic ArPd(I) or its further reduced ArPd(0)- species, which reacted with CO2 to give carboxylic acids. Hydrodehalogenated compounds, main byproducts in this carboxylation, were thought to be generated by protonation of these reduced species.
A method of synthesis of piperonolamine
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Paragraph 0144-0147; 0157-0160, (2022/01/07)
The present invention belongs to the field of organic chemical synthesis, specifically relates to a synthesis method of piperine, comprising: using catechol as a raw material to prepare piperonaldehyde; β - nitro-3,4-dioxenosylstyrene prepared with piperonaldehyde; β - nitro -3,4-dioxenesimethylenestyrene to obtain piperine ethylamine. Among them, the preparation of piperaldehyde from catechol as raw materials includes two ways: (1) catechol→3,4-dihydroxymandelic acid→3,4-dihydroxybenzaldehyde→ piperaldehyde; (2) catechol→ piperine ring → piperine. The raw materials used in the present invention are safe and readily available, low cost; the reaction conditions are mild, the operation is simple, the chemical yield is high, and the intermediate reagents are easy to recover; suitable for industrial production.
Photo-induced thiolate catalytic activation of inert Caryl-hetero bonds for radical borylation
K?nig, Burkhard,Wang, Hua,Wang, Shun
, p. 1653 - 1665 (2021/06/17)
Substantial effort is currently being devoted to obtaining photoredox catalysts with high redox power. Yet, it remains challenging to apply the currently established methods to the activation of bonds with high bond dissociation energy and to substrates with high reduction potentials. Herein, we introduce a novel photocatalytic strategy for the activation of inert substituted arenes for aryl borylation by using thiolate as a catalyst. This catalytic system exhibits strong reducing ability and engages non-activated Caryl–F, Caryl–X, Caryl–O, Caryl–N, and Caryl–S bonds in productive radical borylation reactions, thus expanding the available aryl radical precursor scope. Despite its high reducing power, the method has a broad substrate scope and good functional-group tolerance. Spectroscopic investigations and control experiments suggest the formation of a charge-transfer complex as the key step to activate the substrates.
H2-Free Selective Dehydroxymethylation of Primary Alcohols over Palladium Nanoparticle Catalysts
Yamaguchi, Sho,Kondo, Hiroki,Uesugi, Kohei,Sakoda, Katsumasa,Jitsukawa, Koichiro,Mitsudome, Takato,Mizugaki, Tomoo
, p. 1135 - 1139 (2020/12/29)
The dehydroxymethylation of primary alcohols is a promising strategy to transform biomass-derived oxygenates into hydrocarbon fuels. In this study, a novel, highly efficient, and reusable heterogeneous catalyst system was established for the H2-free dehydroxymethylation of primary alcohol using cerium oxide-supported palladium nanoparticles (Pd/CeO2). A wide range of aliphatic and aromatic alcohols including biomass-derived alcohols were converted into the corresponding one-carbon shorter hydrocarbons in high yields in the absence of any additives, accompanied by the production of H2 and CO. Pd/CeO2 was easily recovered from the reaction mixture and reused, retaining its high activity, thus, providing a simple and sustainable methodology to produce hydrocarbon fuels from biomass-derived oxygenates.
Catalytic Reductions Without External Hydrogen Gas: Broad Scope Hydrogenations with Tetrahydroxydiboron and a Tertiary Amine
Korvinson, Kirill A.,Akula, Hari K.,Malinchak, Casina T.,Sebastian, Dellamol,Wei, Wei,Khandaker, Tashrique A.,Andrzejewska, Magdalena R.,Zajc, Barbara,Lakshman, Mahesh K.
supporting information, p. 166 - 176 (2020/01/02)
Facile reduction of aryl halides with a combination of 5% Pd/C, B2(OH)4, and 4-methylmorpholine is reported. Aryl bromides, iodides, and chlorides were efficiently reduced. Aryl dihalides containing two different halogen atoms underwent selective reduction: I over Br and Cl, and Br over Cl. Beyond these, aryl triflates were efficiently reduced. This combination was broadly general, effectuating reductions of benzylic halides and ethers, alkenes, alkynes, aldehydes, and azides, as well as for N-Cbz deprotection. A cyano group was unaffected, but a nitro group and a ketone underwent reduction to a low extent. When B2(OD)4 was used for aryl halide reduction, a significant amount of deuteriation occurred. However, H atom incorporation competed and increased in slower reactions. 4-Methylmorpholine was identified as a possible source of H atoms in this, but a combination of only 4-methylmorpholine and Pd/C did not result in reduction. Hydrogen gas has been observed to form with this reagent combination. Experiments aimed at understanding the chemistry led to the proposal of a plausible mechanism and to the identification of N,N-bis(methyl-d3)pyridin-4-amine (DMAP-d6) and B2(OD)4 as an effective combination for full aromatic deuteriation. (Figure presented.).
Synthetic method for preparing benzodioxole under catalysis of composite alkali
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Paragraph 0023-0030, (2020/04/22)
The invention discloses a synthetic method for preparing benzodioxole under the catalysis of a composite alkali. According to the method, in a weakly alkaline environment subjected to nitrogen replacement or protection, N-methyl pyrrolidone is used as a solvent medium, catechol and dihaloalkane are used as raw materials, dichloromethane continuously added in a synthesis process is azeotropic withwater generated in a reaction, and dichloromethane refluxes into a reaction container again after water separation, so that benzodioxole is synthesized.
PROCESS FOR THE PREPARATION OF 2,2-DIFLUORO-1,3-BENZODIOXOLE AND INTERMEDIATES THEREOF
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Page/Page column 4-5, (2020/05/15)
The present invention relates to a process for preparing 2,2-difluoro-1,3-benzodioxole. The process comprises a step of reacting 1,3-benzodioxole with chlorine in benzotrifluoride in the present of a radical initiator. The present invention also relates to the process for preparing 2,2-dichloro-1,3-benzodioxole which is used as an intermediate in preparation of 2,2-difluoro-1,3-benzodioxole.
