- Electrophotocatalytic C?H Heterofunctionalization of Arenes
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The electrophotocatalytic heterofunctionalization of arenes is described. Using 2,3-dichloro-5,6-dicyanoquinone (DDQ) under a mild electrochemical potential with visible-light irradiation, arenes undergo oxidant-free hydroxylation, alkoxylation, and amination with high chemoselectivity. In addition to batch reactions, an electrophotocatalytic recirculating flow process is demonstrated, enabling the conversion of benzene to phenol on a gram scale.
- Huang, He,Lambert, Tristan H.
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supporting information
p. 11163 - 11167
(2021/04/19)
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- Palladium-Catalyzed C(sp3)?H Arylation of Primary Amines Using a Catalytic Alkyl Acetal to Form a Transient Directing Group
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C?H Functionalization of amines is a prominent challenge due to the strong complexation of amines to transition metal catalysts, and therefore typically requires derivatization at nitrogen with a directing group. Transient directing groups (TDGs) permit C?H functionalization in a single operation, without needing these additional steps for directing group installation and removal. Here we report a palladium catalyzed γ-C?H arylation of amines using catalytic amounts of alkyl acetals as transient activators (e.g. commercially available (2,2-dimethoxyethoxy)benzene). This simple additive enables arylation of amines with a wide range of aryl iodides. Key structural features of the novel TDG are examined, demonstrating an important role for the masked carbonyl and ether functionalities. Detailed kinetic (RPKA) and mechanistic investigations determine the order in all reagents, and identify cyclopalladation as the turnover limiting step. Finally, the discovery of an unprecedented off-cycle free-amine directed ?-cyclopalladation of the arylation product is reported.
- St John-Campbell, Sahra,Ou, Alex K.,Bull, James A.
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supporting information
p. 17838 - 17843
(2018/11/23)
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- Benzene C-H Etherification via Photocatalytic Hydrogen-Evolution Cross-Coupling Reaction
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Aryl ethers can be constructed from the direct coupling between the benzene C-H bond and the alcohol O-H bond with the evolution of hydrogen via the synergistic merger of photocatalysis and cobalt catalysis. Utilizing the dual catalyst system consisting of 3-cyano-1-methylquinolinum photocatalyst and cobaloxime, intermolecular etherification of arenes with various alcohols and intramolecular alkoxylation of 3-phenylpropanols with formation of chromanes are accomplished. These reactions proceed at remarkably mild conditions, and the sole byproduct is equivalent hydrogen gas.
- Zheng, Yi-Wen,Ye, Pan,Chen, Bin,Meng, Qing-Yuan,Feng, Ke,Wang, Wenguang,Wu, Li-Zhu,Tung, Chen-Ho
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supporting information
p. 2206 - 2209
(2017/05/12)
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- High-Throughput Screening Protocol for the Coupling Reactions of Aryl Halides Using a Colorimetric Chemosensor for Halide Ions
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Mercury complex of 4-(2-pyridylazo)resorcinol (PAR-2Hg2+), a halide-ion chemosensor, was prepared and its efficiency as a tool for high-throughput screening (HTS) of transition-metal-catalyzed coupling reactions was investigated. It showed a high selectivity for halide ions. When the PAR-2Hg2+ complex was used in the Suzuki coupling reaction and C-H activated coupling reaction with aryl bromides, the quantitative and qualitative conversions of aryl halides were obtained from the reaction mixture color change.
- Eom, Min Sik,Noh, Jieun,Kim, Han-Sung,Yoo, Soyeon,Han, Min Su,Lee, Sunwoo
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supporting information
p. 1720 - 1723
(2016/05/19)
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- Behaviour of iprit carbonate analogues in solventless reactions
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Sulfur iprit carbonate analogues have been investigated in neat conditions at atmospheric pressure, in the presence and in the absence of a catalytic amount of base. Furthermore, their reaction mechanism has been discussed in detail. In these novel reaction conditions, sulfur mustard carbonate analogues, that previously showed poor or no reactivity, remarkably undergo efficient nucleophilic substitution with several substrates. This journal is the Partner Organisations 2014.
- Arico',Evaristo,Tundo
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p. 31071 - 31078
(2014/08/05)
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- Sulfur and nitrogen mustard carbonate analogues
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Sulfur and nitrogen half-mustard compounds lose their aggressive properties when the chlorine atom is replaced by a carbonate moiety. The anchimeric effect of the novel mustard carbonate analogues is investigated. The reaction follows first-order kinetics, does not need any base, and occurs with -OH, -NH and acidic -CH nucleophiles. Most of these molecules are unexplored and might provide a novel strategy for the preparation of compounds previously not easily accessible. Copyright
- Arico, Fabio,Chiurato, Matteo,Peltier, Josephine,Tundo, Pietro
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scheme or table
p. 3223 - 3228
(2012/07/31)
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- 2-Phenoxyethanol derived diselenide and related compounds; Synthesis of a seven-membered seleninate ester
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Syntheses of several diorganodiselenides and, in particular, a seven-membered cyclic seleninate ester derived from 2-phenoxyethanol are described. The seleninate ester was obtained from allyl (2-(2-hydroxyethoxy) phenyl) selenide through a series of oxidation and [2,3] sigmatropic rearrangement steps. The ester exhibits good GPx-like activity in the coupled reductase assay.
- Tripathi, Santosh K.,Sharma, Sagar,Singh, Harkesh B.,Butcher, Ray J.
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scheme or table
p. 581 - 587
(2011/03/17)
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- Diazotisation of aromatic amines and solvolysis of diazonium salts in ethylene glycol ethers
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Aniline and unhindered alkyl-substituted anilines undergo solvolysis in dioxane and DME saturated with dry hydrogen chloride on diazotisation with isoamyl nitrite to give 2-(2-chloroethoxy)ethyl aryl ethers and 2-methoxyethyl aryl ethers respectively in 36-47% yields. 2,6-Dialkyl-substituted anilines give the corresponding chloro compounds as the major product along with the aryl ethers in lower yields. Diazotisation of aniline in ethylene glycol and monomethyl ethers of ethylene glycol and diethylene glycol gave the corresponding alcoholysis products in low yields. The solvolysis of aniline did not occur on diazotisation in diethyl ether or THF.
- Ram, Ram N.,Singh, Virinder
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p. 800 - 803
(2007/10/03)
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- Keratinocyte growth inhibitors and hydroxamic acid derivatives
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This invention relates to a keratinocyte-proliferation inhibitor comprising as active ingredient a compound having an activity of inhibiting the solubilization of heparin-binding EGF-like growth factor bound to cell membranes and a compound of the formula (I); or pharmaceutically acceptable salt thereof, wherein R1, R2, R3 are hydrogen atom or alkyl and X is substituted benzene or the like.
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- Process for the preparation of 2-methoxyethoxy-benzenes and novel 2-methoxyethoxy-benzyl cyanides
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2-Methoxyethoxy-benzenes are obtained in an advantageous manner from the corresponding phenol compounds by reaction with 2-chloroethyl methyl ether if the process is carried out without the addition of a strong solvent at temperatures above 95° C. and under pressure. The present invention also relates to novel 2-methoxyethoxy-benzyl cyanides.
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- Heterocyclic derivatives and their use as antithrombotic agents
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The present invention relates to antithrombotic compounds comprising the group Q, Q having formula (I), wherein the substructure (i) is a structure selected from (a, b and c), wherein X is O or S; X′ being independently CH or N; and m is 0, 1, 2 or 3; wherein the group Q is bound through an oxygen atom or an optionally substituted nitrogen or carbon atom, or a pharmaceutically acceptable salt thereof or a prodrug thereof. The compounds of the invention are therapeutically active and in particular are antithrombotic agents.
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- Dicyclohexylethyleneglycol,-diethyleneglycol,-triethyleneglycol, and related monosubstituted cyclohexanes. Conformational analysis using low-temperature 13C and 1H NMR spectroscopy
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Two conformations of each of the title molecules have been detected by 100 MHz 13C NMR at 210 K.For the dicyclohexyl systems, the conformations are related via a single ring inversion.In each case the equatorial-axial conformer is 4,7+/-0.4 kJ/mol less stable than the diequatorially substituted form in CD2Cl2 solution.For monosubstituted models, the conformational free energy (-ΔG deg) values of the -O-CH2-CH2-OCH3, -OCH2-CH2-O-CH2-CH3, and -O-CH2-CH2-O-CH-(CH3)2 groups have been determined to be 5.4, 6.1, and 6.1+/-0.2 kJ/mol, respectively.In methanol, the latter equilibria are slightly more biased towards the axially substituted conformers. Key words: substituted ethylene glycols, conformational equilibria.
- Buchanan, G. W.,Moghimi, A.,Reynolds, V. M.,Bourque, K.
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p. 566 - 572
(2007/10/02)
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- Copper(I) Halide Catalysed Synthesis of Alkyl Aryl and Alkyl Heteroaryl Ethers
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A number of alkyl aryl and alkyl heteroaryl ethers have been prepared from (hetero) aryl halides (mainly bromides) and sodium alkoxides, using copper(I)bromide as a catalyst.The influence of the main solvent, the halogen atom, reaction temperature and the presence of oxygen upon the rate and selectivity has been studied.Furthermore the decomposition of the catalyst and the reduction of the aryl halide are studied.
- Keegstra, Menno A.,Peters, Theo H. A.,Brandsma, Lambert
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p. 3633 - 3652
(2007/10/02)
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- The Catalytic Effect of Copper Ions in the Phenylation Reaction of David and Thieffry
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Several types of bifunctional molecules are smoothly phenylated by triphenylbismuth diacetate in a reaction which has an induction period, a curious solvent dependence, and the need for illumination; however, the addition of a small amount of Cu(OAc)2 removes all these limitations and accelerates greatly the reaction.
- Barton, Derek H. R.,Finet, Jean-Pierre,Pichon, Clotilde
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- ortho-Directed Lithiation of (2-Methoxy)ethoxy- and (2-Dimethylamino)ethoxy-arenes
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ortho-Directed lithiation of a number of (2-methoxy)ethoxy- and (2-dimethylamino)ethoxy-arenes has been investigated.Lithiation of these compounds followed by treatment with various electrophiles afforded ortho-substituted products in moderate to excellent yields.Keywords-ortho-directed lithiation; (2-methoxy)ethoxyarene; (2-dimethylamino)ethoxyarene; regioselectivity
- Wada, Akimori,Kanatomo, Shoichi,Nagai, Sotoo
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p. 1016 - 1022
(2007/10/02)
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