- CATALYTIC CARBOXYLATION OF ACTIVATED ALKANES AND/OR OLEFINS
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The present invention relates to a method of reacting starting materials with an activating group, namely alkanes carrying a leaving group and/or olefins, with carbon dioxide under transition metal catalysis to give carboxyl group-containing products. It is a special feature of the method of the present invention that the carboxylation predominantly takes place at a preferred position of the molecule irrespective of the position of the activating group. The carboxylation position is either an aliphatic terminus of the molecule or it is a carbon atom adjacent to a carbon carrying an electron withdrawing group. The course of the reaction can be controlled by appropriately choosing the reaction conditions to yield the desired regioisomer.
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Page/Page column 57; 62; 63; 65; 66
(2018/02/28)
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- Nickel-catalysed direct alkylation of thiophenes via double C(sp3)-H/C(sp2)-H bond cleavage: The importance of KH2PO4
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A Ni-catalyzed oxidative C-H/C-H cross-dehydrogenative coupling (CDC) reaction was developed for constructing various highly functionalized alkyl (aryl)-substituted thiophenes. This method employs thiophenes and aliphatic (aromatic) amides that contain an 8-aminoquinoline as a removable directing group in the presence of a silver oxidant. The approach enables the facile one-step synthesis of substituted thiophenes with high functional group compatibility via double C-H bond cleavage without affecting C-Br and C-I bonds. DFT calculations verify the importance of KH2PO4 as an additive for promoting C-H bond cleavage and support the involvement of a Ni(iii) species in the reaction.
- Wang, Xie,Xie, Peipei,Qiu, Renhua,Zhu, Longzhi,Liu, Ting,Li, You,Iwasaki, Takanori,Au, Chak-Tong,Xu, Xinhua,Xia, Yuanzhi,Yin, Shuang-Feng,Kambe, Nobuaki
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supporting information
p. 8316 - 8319
(2017/07/26)
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- Synthesizing method of pesticide intermediate 1-methylcyclohexanecarboxylic acid
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The invention discloses a synthesizing method of a pesticide intermediate 1-methylcyclohexanecarboxylic acid. The 1-methylcyclohexanecarboxylic acid is prepared by taking 2-methylcyclohexanol, formic acid and an R-Cl halogenating reagent as the raw materials through halogenation and substitution reactions by means of a one-pot method. The synthesizing method is novel, the defects in a traditional production process can be overcome, emission of waste acid water is reduced, the production capacity is enlarged, and the synthesizing method is green and environmentally friendly.
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Paragraph 0019; 0020
(2017/06/02)
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- Nickel-catalyzed directed sulfenylation of sp2 and sp3 C-H bonds
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Directed sulfenylation of both sp2 and sp3 C-H bonds was achieved through nickel catalyzed directed C-S bond formation, giving the desired product in good to excellent yield (up to 90%). Other metal cations, including Cu, Fe, Pd, Rh, Ru and Co, gave almost no reaction under identical conditions, which highlighted the unique reactivity of this Ni system.
- Ye, Xiaohan,Petersen, Jeffrey L.,Shi, Xiaodong
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supporting information
p. 7863 - 7866
(2015/05/13)
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- Nickel-Catalyzed Addition-Type Alkenylation of Unactivated, Aliphatic C-H Bonds with Alkynes: A Concise Route to Polysubstituted γ-Butyrolactones
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(Chemical Equation Presented). Through the nickel-catalyzed chelation-assisted C-H bond activation strategy, the addition-type alkenylation of unreactive β-C(sp3)-H bonds of aliphatic amides with internal alkynes is developed for the first time to produce γ,δ-unsaturated carboxylic amide derivatives. The resulting alkenylated products can further be transformed into polysubstituted γ-butyrolactones with pyridinium chlorochromate (PCC).
- Li, Mingliang,Yang, Yudong,Zhou, Danni,Wan, Danyang,You, Jingsong
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supporting information
p. 2546 - 2549
(2015/05/27)
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- β-Arylation of carboxamides via iron-catalyzed C(sp3)-H bond activation
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A 2,2-disubstituted propionamide bearing an 8-aminoquinolinyl group as the amide moiety can be arylated at the β-methyl position with an organozinc reagent in the presence of an organic oxidant, a catalytic amount of an iron salt, and a biphosphine ligand at 50 C. Various features of selectivity and reactivity suggest the formation of an organometallic intermediate via rate-determining C-H bond cleavage rather than a free-radical-type reaction pathway.
- Shang, Rui,Ilies, Laurean,Matsumoto, Arimasa,Nakamura, Eiichi
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supporting information
p. 6030 - 6032,3
(2013/05/22)
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- Enantioselective borohydride reduction of aliphatic ketones catalyzed by ketoiminatocobalt(iii) complex with 1-chlorovinyl axial ligand
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For the enantioselective borohydride reduction of aliphatic ketones, the optically active ketoiminatocobalt(II) catalysts was successfully designed based on their axial ligand. Instead of chloroform for the aryl ketone reduction, various axial ligand precursors were examined for the aliphatic ketone. Consequently, 1, 1, 1-trichloroethane was found to be the most effective activator of the cobalt(II) complexes to generate the corresponding 1-chlorovinyl cobalt(III) derivatives as the reactive intermediate. Several aliphatic ketones were successfully reduced to afford the corresponding secondary alcohols with high enantioselectivities.
- Tsubo, Tatsuyuki,Chen, Hsiu-Hui,Yokomori, Minako,Fukui, Kosuke,Kikuchi, Satoshi,Yamada, Tohru
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supporting information; experimental part
p. 780 - 782
(2012/09/22)
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- The introduction of P4 substituted 1-methylcyclohexyl groups into Boceprevir: A change in direction in the search for a second generation HCV NS3 protease inhibitor
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In the search for a second generation HCV protease inhibitor, molecular modeling studies of the X-ray crystal structure of Boceprevir 1 bound to the NS3 protein suggest that expansion into the S4 pocket could provide additional hydrophobic Van der Waals interactions. Effective replacement of the P4 tert-butyl with a cyclohexylmethyl ligand led to inhibitor 2 with improved enzyme and replicon activities. Subsequent modeling and SAR studies led to the pyridine 38 and sulfone analogues 52 and 53 with vastly improved PK parameters in monkeys, forming a new foundation for further exploration.
- Bennett, Frank,Huang, Yuhua,Hendrata, Siska,Lovey, Raymond,Bogen, Stephane L.,Pan, Weidong,Guo, Zhuyan,Prongay, Andrew,Chen, Kevin X.,Arasappan, Ashok,Venkatraman, Srikanth,Velazquez, Francisco,Nair, Latha,Sannigrahi, Mousumi,Tong, Xiao,Pichardo, John,Cheng, Kuo-Chi,Girijavallabhan, Viyyoor M.,Saksena, Anil K.,Njoroge, F. George
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scheme or table
p. 2617 - 2621
(2010/07/05)
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- Metal-free and copper-promoted single-pot hydrocarboxylation of cycloalkanes to carboxylic acids in aqueous medium
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A simple and effective method for the transformation, under mild conditions and in aqueous medium, of various cycloalkanes (cyclopentane, cyclohexane, methylcyclohexane, cis- and trans-1,2dimethylcyclohexane, cycloheptane, cyclooctane and adamantane) into the corresponding cycloalkanecarboxylic acids bearing one more carbon atom, is achieved. This method is characterized by a singlepot, low-temperature hydrocarboxylation reaction of the cycloalkane with carbon monoxide, water and potassium peroxodisulfate in water/acetonitrile medium, proceeding either in the absence or in the presence of a metal promoter. The influence of various reaction parameters, such as type and amount of metal promoter, solvent composition, temperature, time, carbon monoxide pressure, oxidant and cycloalkane, is investigated, leading to an optimization of the cyclohexane and cyclopentane carboxylations. The highest efficiency is observed in the systems promoted by a tetracopper(II) triethanolaminate-de rived complex, which also shows different bond and stereoselectivity parameters (compared to the metalfree systems) in the carboxylations of methylcyclohexane and stereoisomeric 1,2-dimethylcyclohexanes. A free radical mechanism is proposed for the carboxylation of cyclohexane as a model substrate, involving the formation of an acyl radical, its oxidation and consequent hydroxylation by water. Relevant features of the present hydrocarboxylation method, besides the operation in aqueous medium, include the exceptional metal-free and acid-solvent-free reaction conditions, a rare hydroxylating role of water, substrate versatility, low temperatures (ca. 50°C) and a rather high efficiency (up to 72% carboxylic acid yields based on cycloalkane).
- Kirillova, Marina V.,Kirillov, Alexander M.,Pombeiro, Armando J. L.
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experimental part
p. 2936 - 2948
(2010/04/03)
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- Process for synthesis of tertiary carboxylic acids and the esters thereof
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The present invention provides a process for synthesizing tertiary carboxylic acids or the esters thereof having one or two more carbon atoms than the raw material has, comprising reacting in a strong acid (e.g., sulfuric acid, sulfuric acid-phosphoric acid, hydrogen fluoride, fluorosulfuric acid, boron trifluoride.water complex and trifluoromethanesulfonic acid) a raw material compound (i.e., olefin, alcohol, diene, diol or saturated hydrocarbon) with carbon monoxide in the presence of a specific metal carbonyl catalyst (i.e., platinum carbonyl catalyst, palladium carbonyl catalyst and gold dicarbonyl catalyst). The metal carbonyl catalyst is formed by reacting in a strong acid at least one specific metal compounds (e.g., platinum compound such as platinum (II, IV) oxide, platinum (II, IV) hydroxide, a platinum powder, etc.; palladium compound such as palladium (II, III, IV) oxide, palladium (II) hydroxide, palladium (II) sulfate, palladium (II) carboxylate, a palladium powder, etc.; and gold compound such as gold (I, III) oxide, gold (I, III) hydroxide, a gold powder, etc.) with carbon monoxide.
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- On the mechanism of the intramolecular samarium barbier reaction. Probes for formation of radical and organosamarium intermediates
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A new type of mechanistic probe for the intramolecular samarium Barbier reaction has been designed, and two different probe substrates have been investigated in detail. Remarkably, no unambiguous evidence could be obtained in favor of any of the obvious intermediates (free alkyl or alkoxy radicals, ketyls, organosamarium species) that are postulated for this reaction. Several possibilities for modified mechanisms are suggested.
- Curran, Dennis P.,Gu, Xin,Zhang, Wei,Dowd, Paul
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p. 9023 - 9042
(2007/10/03)
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- Shape and aggregating tendency. The aggregating behavior of eight esters of eight-carbon carboxylic acids
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The aggregating tendencies of eight p-nitrophenyl esters of eight-carbon carboxylic acids (1-8) and two O-octyl phosphonates (10, 11) have been evaluated by measuring their critical aggregate concentrations (CAgG's). Results show that (1) branching reduce
- Jiang, Xi-Kui,Ji, Guo-Zhen,Tu, Bo,Zhang, Xin-Yu,Shi, Ji-Liang,Chen, Xin
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p. 12679 - 12682
(2007/10/03)
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- ACTIVATION AND SYNTHETIC APPLICATION OF THIOSTANNANES. PROTECTION OF CARBOXYL GROUPS WITH α-METHYLCINNAMYL ALCOHOL AS A MEANS OF CHEMODIFFERENTIATION AND SELECTIVE ACTIVATION
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α-Methylcinnamyl (MEC) esters are converted into parent carboxylic acids under mild conditions, various functions being tolerated including acetoxy, siloxy, MEM, and so on.Furthermore, MEC esters are transformed into other esters through CsF-promoted alkylation of intermediary organotin carboxylates.
- Sato, Tsueno,Otera, Junzo,Nozaki, Hitoshi
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p. 2959 - 2962
(2007/10/02)
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- Pharmaceutically active cyclohexyl compounds and their preparation
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The chemical compounds of the invention are useful as the active compound in drugs because of their anticonvulsant and/or antianoxic activity. They have the general formula STR1 wherein Z is a hydroxyl group; a group--OM wherein M is an alkali metal atom or an equivalent atom fraction of an alkaline-earth metal or an amino group such as --NH2, and R is a linear or branched alkyl group containing from 1 to 9 carbon atoms, and optionally substituted by one or more halogen atoms; a linear or branched alkenyl or alkynyl, alkoxyalkyl, or acylalkyl group containing from 2 to 9 carbon atoms and optionally substituted by one or more halogen atoms; an aryl or arylalkyl or aryloxyalkyl group comprising at least one aromatic radical and an alkyl chain having from 1 to 4 carbon atoms.
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