- Visible-Light-Enabled Carboxylation of Benzyl Alcohol Derivatives with CO2 Using a Palladium/Iridium Dual Catalyst
-
A highly efficient carboxylation of benzyl alcohol derivatives with CO2 using a palladium/iridium dual catalyst under visible-light irradiation was developed. A wide range of benzyl alcohol derivatives could be employed to provide benzylic carboxylic acids in moderate to high yields. Mechanistic studies indicated that the oxidative addition of benzyl alcohol derivatives was possibly the rate-determining-step. It was also found that a switchable site-selective carboxylation between benzylic C?O and aryl C?Cl moieties could be achieved simply by changing the palladium catalyst.
- Iwasawa, Nobuharu,Jin, Yushu,Toriumi, Naoyuki
-
-
- Alkali-modified heterogeneous Pd-catalyzed synthesis of acids, amides and esters from aryl halides using formic acid as the CO precursor
-
To establish an environmentally friendly green chemical process, we minimized and resolved a significant proportion of waste and hazards associated with conventional organic acids and molecular gases, such as carbon monoxide (CO). Herein, we report a facile and milder reaction procedure, using low temperatures/pressures and shorter reaction time for the carboxyl- and carbonylation of diverse arrays of aryl halides over a newly developed cationic Lewis-acid promoted Pd/Co3O4catalyst. Furthermore, the reaction proceeded in the absence of acid co-catalysts, and anhydrides for CO release. Catalyst reusability was achievedviascalable, safer, and practical reactions that provided moderate to high yields, paving the way for developing a novel environmentally benign method for synthesizing carboxylic acids, amides, and esters.
- Fapojuwo, Dele Peter,Maqunga, Nomathamsanqa Prudence,Meijboom, Reinout,Mogudi, Batsile M.,Molokoane, Pule Petrus,Onisuru, Oluwatayo Racheal,Oseghale, Charles O.
-
p. 26937 - 26948
(2021/08/17)
-
- Synthesis method of 3-isochromanone
-
The invention belongs to the technical field of synthesis of organic intermediates, and particularly relates to a synthesis method of 3-isochromanone, which comprises the following steps of: (1) synthesizing o-methyl benzyl chloride by using o-xylene as a raw material; (2) synthesizing o-methyl benzyl cyanide by taking o-methyl benzyl chloride as a raw material; (3) synthesizing sodium o-methyl phenylacetate by taking o-methyl benzyl cyanide as a raw material; (4) synthesizing o-methyl phenylacetic acid by taking sodium o-methyl phenylacetate as a raw material; (5) synthesizing 2-chloromethylphenylacetic acid by taking o-methyl phenylacetic acid as a raw material; and (6) synthesizing 3-isochromanone by taking 2-chloromethyl phenylacetic acid as a raw material. The synthesis method of 3-isochromanone has the advantages of simple reaction process, easily available raw materials, mild reaction conditions, high product yield, low production cost, high yield, high product purity, good quality, low production waste discharge amount and the like, the product purity is greater than or equal to 99.5%, the production yield is greater than or equal to 92%, and the product meets the use requirements of foreign high-end users.
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- Pd(OH)2/C, a Practical and Efficient Catalyst for the Carboxylation of Benzylic Bromides with Carbon Monoxide
-
A simple, efficient, cheap, and broadly applicable system for the carboxylation of benzylic bromides with carbon monoxide and water is reported. Upon simple reaction with only 2.5 wt % of Pearlman's catalyst and 10 mol % of tetrabutylammonium bromide in tetrahydrofuran at 110 °C for 4 h, a range of benzylic bromides can be smoothly converted to the corresponding arylacetic acids in good to excellent yields after simple extraction and acid-base wash. The reaction was found to be broadly applicable, scalable, and could be successfully extended to the use of ex situ-generated carbon monoxide and applied to the synthesis of the nonsteroidal anti-inflammatory drug diclofenac.
- Wakuluk-Machado, Anne-Marie,Dewez, Damien F.,Baguia, Hajar,Imbratta, Miguel,Echeverria, Pierre-Georges,Evano, Gwilherm
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p. 713 - 723
(2020/02/04)
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- Carboxylation of benzylic and aliphatic C-H bonds with CO2 induced by light/ketone/nickel
-
A photoinduced carboxylation reaction of benzylic and aliphatic C-H bonds with CO2 is developed. Toluene derivatives capture gaseous CO2 at the benzylic position to produce phenylacetic acid derivatives when irradiated with UV light in the presence of an aromatic ketone, a nickel complex, and potassium tert-butoxide. Cyclohexane reacts with CO2 to furnish cyclohexanecar-boxylic acid under analogous reaction conditions. The present photoinduced carboxylation reaction provides a direct access from readily available hydrocarbons to the corresponding carboxylic acids with one carbon extension.
- Ishida, Naoki,Masuda, Yusuke,Imamura, Yuuya,Yamazaki, Katsushi,Murakami, Masahiro
-
supporting information
p. 19611 - 19615
(2019/12/24)
-
- Preparation method of phenylacetic acid type compound
-
The invention discloses a preparation method of a phenylacetic acid type compound. The preparation method of the phenylacetic acid type compound I comprises the following steps that in a solvent and aCO gas phase system, a benzyl halide type compound II, pyridine-2-cobalt carboxylate, palladium acetate and alkaline neutralizers take carbonylation reaction to obtain the phenylacetic acid type compound I. A mixed catalytic system has a synergistic effect; the whole use quantity of catalysts is greatly reduced. When the mixed catalyst is used, a better catalytic effect can be achieved; the characteristics of easily obtaining the catalyst, avoiding the production safety risk of toxic three wastes and the like, reducing the reaction pressure, realizing mild reaction conditions, reducing the production risk, facilitating the production and the like are realized. The formulas are shown in description.
- -
-
Paragraph 0110; 0111; 0112
(2019/02/21)
-
- Synthesis and biological evaluation of 3-arylcoumarin derivatives as potential anti-diabetic agents
-
A variety of substituted 3-arylcoumarin derivatives were synthesised through microwave radiation heating. The method has characteristics of environmental friendliness, economy, simple separation, and purification process, less by-products and high reaction yield. Those 3-arylcoumarin derivatives were screened for antioxidant, α-glucosidase inhibitory and advanced glycation end-products (AGEs) formation inhibitory. Most compounds exhibited significant antioxidant and AGEs formation inhibitory activities. Anti-diabetic activity studies showed that compounds 11 and 17 were equipotent to the standard drug glibenclamide in vivo. According to the experimental results, the target compound 35 can be used as a lead compound for the development of new anti-diabetic drugs. The whole experiment showed that anti-diabetic activity is prevalent in 3-arylcoumarins, which added a new natural skeleton to the development of anti-diabetic active drugs.
- Hu, Yuheng,Wang, Bing,Yang, Jie,Liu, Teng,Sun, Jie,Wang, Xiaojing
-
-
- An improved method for the synthesis of phenylacetic acid derivatives via carbonylation
-
2,4-Dichlorophenylacetic acid is synthesized in high yield via the carbonylation of 2,4-dichlorobenzyl chloride, and various experimental conditions are evaluated. Xylene, bistriphenylphosphine palladium dichloride, tetraethylammonium chloride and sodium hydroxide in solution are added to the reaction system and held at 80 °C under a CO atmosphere. 2,4-Dichlorophenylacetic acid is obtained in a maximum yield of 95percent, and a mechanism for 2,4-dichlorobenzyl chloride carbonylation is proposed. The reaction system provides a mild, effective and novel means by which to prepare phenylacetic acid derivatives from their corresponding benzyl chloride derivatives.
- Li, He,Zhang, Yijun,Liu, Dinghua,Liu, Xiaoqin
-
p. 548 - 552
(2019/11/13)
-
- A General, Activator-Free Palladium-Catalyzed Synthesis of Arylacetic and Benzoic Acids from Formic Acid
-
A new catalyst for the carboxylative synthesis of arylacetic and benzoic acids using formic acid (HCOOH) as the CO surrogate was developed. In an improvement over previous work, CO is generated in situ without the need for any additional activators. Key to success was the use of a specific system consisting of palladium acetate and 1,2-bis((tert-butyl(2-pyridinyl)phosphinyl)methyl)benzene. The generality of this method is demonstrated by the synthesis of more than 30 carboxylic acids, including non-steroidal anti-inflammatory drugs (NSAIDs), under mild conditions in good yields.
- Wang, Lin,Neumann, Helfried,Beller, Matthias
-
supporting information
p. 6910 - 6914
(2018/06/04)
-
- The selenium-containing complexes in the phenylacetic acid and its derivatives or its application in the synthesis of (by machine translation)
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The present invention provides a kind of structural formula (I) indicated by the 2 - (2 - carboxyl phenyl) benzothiazole of selenium-containing complexes of, this kind of selenium-containing complex can be applied to the catalytic benzyl chloride rigid synthetic phenylacetic acid or derivatives thereof in the reaction, in the reaction, the less the amount of catalyst, the catalytic activity is high, simple operation, conducive to such synthetic method in industry popularization and application. (by machine translation)
- -
-
Paragraph 0019-0022
(2018/07/30)
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- A phenylacetic acid compound preparation method (by machine translation)
-
The invention relates to the field of chemical synthesis, in particular relates to a preparation method of the compound of phenylacetic acid. The present invention provides a preparation method of the compound of phenylacetic acid, the acid compounds of the structural formula states the benzene second grade shown in formula I, the preparation method comprises the following steps: (1) diazo addition reaction: formula II compound containing vinylidene chloride, acid, diazotization reagent, phase transfer catalyst and a copper catalyst in the system of the formula III compound: (2) hydrolysis reaction: the compound of formula III in the presence of acid hydrolysis of formula I compounds. The present invention provides a preparation method of and is simple, easy operation, low cost of raw materials, mild reaction conditions, low risk, does not need to use expensive noble metal catalyst and complex industrial operation means, the product quality is stable, therefore easy achievement of large-scale industrial production. (by machine translation)
- -
-
Paragraph 0124
(2018/03/01)
-
- COMPOUNDS FROM RENEWABLE RESOURCES
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Compounds of formula III: and salts thereof are disclosed. Also disclosed are methods for preparing compounds of formula III, intermediates useful for preparing compounds of formula III and methods for preparing compounds and materials from compounds of formula III.
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Paragraph 0322-0325
(2017/10/26)
-
- Preparation method of carboxylic acid compound
-
The invention provides a preparation method of a carboxylic acid compound. The preparation method comprises the following step of taking a lactone component to react with hydrogen in the presence of a compound catalyst to obtain the carboxylic acid compound. The compound catalyst comprises a hydrogenation catalyst and Lewis acid. In the presence of the compound catalyst comprising the hydrogenation catalyst and the Lewis acid, the lactone component is subjected to hydrogenation ring-opening reaction to obtain the carboxylic acid compound. The preparation method has the advantages of moderate reaction conditions and high yield; compared with a traditional method, less byproducts are generated, green and chemical requirements are met and the industrial value is better.
- -
-
Paragraph 0113; 0226-00228
(2017/08/29)
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- A Comprehensive Study on Metal Triflate-Promoted Hydrogenolysis of Lactones to Carboxylic Acids: From Synthetic and Mechanistic Perspectives
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Direct hydrogenolysis of lactone to carboxylic acid (i.e., hydrogenolysis of the Calkoxy-O bond with the carbonyl group untouched) is generally difficult, as the current strategies employing Br?nsted acids as the catalyst usually require harsh conditions such as a high temperature and a high H2 pressure. Herein, we report a developed solvent-free catalytic transformation, in which W(OTf)6 is believed to promote the hydrogenolysis process. This strategy could efficiently hydrogenate lactones to carboxylic acids under extra mild conditions (e.g., a reaction temperature of 2) and showed a broad substrate scope. In addition, the catalytic protocol can be further applied to the hydrogenolysis of polyhydroxyalkanoate, as a renewable polymer, to the corresponding straight-chain carboxylic acids. An extensive mechanistic study was subsequently performed, and the density functional theory calculations revealed a reaction pattern, including the complete cleavage of the C=O bond with the assistance of the W(OTf)6 catalyst. Moreover, the key intermediate created in the mechanism, as an oxonium with an OTf moiety, was successfully detected by electrospray ionization mass spectra. Through a comparison with the Br?nsted acid-catalyzed system, the study confirmed that the existence of the OTf moiety can significantly lower the barriers associated with the rearrangement and elimination processes. Meanwhile, emphasis was placed on the critical role that the anion plays, as well as the fact that the anion effect is directly related to the chemoselectivity.
- Zhu, Rui,Jiang, Ju-Long,Li, Xing-Long,Deng, Jin,Fu, Yao
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p. 7520 - 7528
(2017/11/10)
-
- Synthetic Applications and Mechanistic Studies of the Hydroxide-Mediated Cleavage of Carbon-Carbon Bonds in Ketones
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The hydroxide-mediated cleavage of ketones into alkanes and carboxylic acids has been reinvestigated and the substrate scope extended to benzyl carbonyl compounds. The transformation is performed with a 0.05 M ketone solution in refluxing xylene in the presence of 10 equiv of potassium hydroxide. The reaction constitutes a straightforward protocol for the synthesis of certain phenyl-substituted carboxylic acids from 2-phenylcycloalkanones. The mechanism was investigated by kinetic experiments which indicated a first order reaction in hydroxide and a full negative charge in the rate-determining step. The studies were complemented by a theoretical investigation where two possible pathways were characterized by DFT/M06-2X. The calculations showed that the scission takes place by nucleophilic attack of hydroxide on the ketone followed by fragmentation of the resulting oxyanion into the carboxylic acid and a benzyl anion.
- Mazziotta, Andrea,Makarov, Ilya S.,Fristrup, Peter,Madsen, Robert
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p. 5890 - 5897
(2017/06/07)
-
- Aromatic Claisen Rearrangements of Benzyl Ketene Acetals: Conversion of Benzylic Alcohols to (ortho-Tolyl)acetates
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Claisen rearrangements of benzyl vinyl ethers are much less facile than those of aliphatic allyl vinyl ethers, and their synthetic utility has remained relatively unexplored. A one-pot procedure is reported for the generation and Claisen rearrangement of benzyl vinyl ethers that contain an activating α-alkoxy substituent on the vinyl group. A [3,3]-sigmatropic mechanism was supported by trapping of the intermediate isotoluene in an intramolecular Alder–ene reaction.
- Burns, Jed M.,Krenske, Elizabeth H.,McGeary, Ross P.
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p. 252 - 256
(2017/01/24)
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- Nickel-Catalyzed Carboxylation of Benzylic C-N Bonds with CO2
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A user-friendly Ni-catalyzed reductive carboxylation of benzylic C-N bonds with CO2 is described. This procedure outperforms state-of-the-art techniques for the carboxylation of benzyl electrophiles by avoiding commonly observed parasitic pathways, such as homodimerization or β-hydride elimination, thus leading to new knowledge in cross-electrophile reactions.
- Moragas, Toni,Gaydou, Morgane,Martin, Ruben
-
supporting information
p. 5053 - 5057
(2016/04/26)
-
- An efficient one pot method for synthesis of carboxylic acids from nitriles using recyclable ionic liquid [bmim]HSO4 Dedicated to my mentor Professor (Mrs.) Krishna Misra on her 76th birthday
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Environmentally benign ionic liquid [bmim]HSO4 was found suitable for conversion of nitriles into carboxylic acids under mild conditions with excellent purity.
- Kumar, Satyanand,Dixit, Sandeep Kumar,Awasthi, Satish Kumar
-
supporting information
p. 3802 - 3804
(2014/07/07)
-
- Palladium-catalyzed silver-mediated α-arylation of acetic acid: A new approach for the α-arylation of carbonyl compounds
-
A new approach for the α-arylation of acetic acid through Pd-catalyzed silver-mediated direct C-H arylation of acetic acid with aryl iodides was developed. This protocol provided a straightforward method for the synthesis of a diverse set of α-phenylacetic acids. Palladium served on a silver platter: A new approach for the α-arylation of acetic acid through Pd-catalyzed silver-mediated direct C-H arylation of acetic acid with aryl iodides is presented. This protocol provides a straightforward method for the synthesis of a diverse set of α-phenylacetic acids. Deuteration experiments are performed to help elucidate the reaction mechanism.
- Wu, Guo-Jie,Guan, Jing,Han, Fu-She,Zhao, Yu-Long
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p. 1589 - 1593
(2014/06/24)
-
- Ketyl-type radicals from cyclic and acyclic esters are stabilized by SmI2(H2O)n: the role of SmI2(H 2O)n in post-electron transfer steps
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Mechanistic details pertaining to the SmI2-H2O- mediated reduction and reductive coupling of 6-membered lactones, the first class of simple unactivated carboxylic acid derivatives that had long been thought to lie outside the reducing range of SmI2, have been elucidated. Our results provide new experimental evidence that water enables the productive electron transfer from Sm(II) by stabilization of the radical anion intermediate rather than by solely promoting the first electron transfer as originally proposed. Notably, these studies suggest that all reactions involving the generation of ketyl-type radicals with SmI2 occur under a unified mechanism based on the thermodynamic control of the second electron transfer step, thus providing a blueprint for the development of a broad range of novel chemoselective transformations via open-shell electron pathways.
- Szostak, Michal,Spain, Malcolm,Procter, David J.
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supporting information
p. 8459 - 8466
(2014/06/24)
-
- PROCESS FOR SYNTHESIZING PHENYLACETIC ACID BY CARBONYLATION OF TOLUENE
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A production process for substituted phenylacetic acids or ester analogues thereof is disclosed. In this process toluene or toluene substituted with various substituents, an alcohol, an oxidant and carbon monoxide are used as raw materials to obtain compounds comprising structure of phenylacetic acid ester or analogues thereof by catalysis of the complex catalyst formed from transition metal and ligand, and such compounds are hydrolyzed to obtain various substituted phenylacetic acid based compounds. This type of compounds and their derivatives serve as important fine chemicals used widely in the industries of pharmaceuticals, pesticides, perfume and the like.
- -
-
Paragraph 0018; 0042; 0043
(2013/11/19)
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- An efficiently cobalt-catalyzed carbonylative approach to phenylacetic acid derivatives
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A highly efficient cobalt-catalyzed carbonylative approach to phenylacetic acid derivatives under one atmosphere pressure is reported. This methodology represents a useful extension of benzimidazole used as ligand in metal catalysis, and the catalytic mechanism has been proved by computer simulation. Notably, this new cobalt precatalyst, which promotes the carbonylation reaction dramatically and has already been used for scale-up experiment of phenylacetic acid derivatives.
- She, Meng-Yao,Xiao, Da-Wei,Yin, Bing,Yang, Zheng,Liu, Ping,Li, Jian-Li,Shi, Zhen
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p. 7264 - 7268
(2013/08/23)
-
- Carboxylic acids from primary alcohols and aldehydes by a pyridinium chlorochromate catalyzed oxidation
-
A facile and quantitative preparation of carboxylic acids by a pyridinium chlorochromate (PCC) catalyzed (2 mol%) oxidation of primary alcohols and aldehydes using 2.2 equivalents and 1.1 equivalents of H5IO 6, respectively, in acetonitrile is described here. Georg Thieme Verlag Stuttgart.
- Hunsen, Mo
-
p. 2487 - 2490
(2007/10/03)
-
- Fluorochromate-catalyzed periodic acid oxidation of alcohols and aldehydes
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Preparation of aldehydes and ketones from alcohols, and carboxylic acids from alcohols and aldehydes using pyridinium fluorochromate (PFC) as a catalyst and H5IO6 as the terminal oxidant is described here.
- Hunsen, Mo
-
p. 1356 - 1360
(2007/10/03)
-
- An efficient method for one-carbon elongation of aryl aldehydes via their dibromoalkene derivatives
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Various aryl aldehydes were efficiently converted into one-carbon extended aryl acetamides or aryl acetic acids through the reaction of their dibromoalkene derivatives with pyrrolidine in the presence of water under very mild conditions.
- Huh, Dal Ho,Jeong, Ji Sang,Lee, Hee Bong,Ryu, Hoejin,Kim, Young Gyu
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p. 9925 - 9932
(2007/10/03)
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- Process for preparing phenylacetic acid derivatives
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A process for preparing phenylacetic acid derivatives of the formula (I) by reacting benzyl chlorides of the formula (II) with a compound of the formula R6OH and with carbon monoxide in a dipolar aprotic solvent in the presence of a catalyst which comprises at least one compound of a transition metal of subgroup VIII of the Periodic Table of the Elements, where R1, R2, R3, R4, and R5 independently of one another are the following radicals: a hydrogen or fluorine atom; a CH2Cl radical; a HO2CCH═CH—, NC- or CF3-group; an alkyl, alkoxy or acyloxy radical having in each case 1 to 18 carbon atoms; or a C6-C18-aryloxy, aryl or heteroaryl radical.
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-
-
- Resolution of 2-bromo-o-tolyl-carboxylic acid by transesterification using lipases from Rhizomucor miehei and Pseudomonas cepacia
-
Several lipases were screened for their ability to catalyze the enantioselective transesterification of 2-bromo-o-tolyl acetic acid. Amongst the preparations tested, the lipases from Rhizomucor miehei and Pseudomonas cepacia were selected. The best enantioselectivity was obtained with Rhizomucor miehei lipase immobilized on polypropylene (E = 11.3), which was more stereoselective than the free form. Hydrophobic solvents with log P higher than 2.5 were the most suitable giving the highest E-values. In addition, factors such as the water activity and the reaction temperature had little effect on the resolution of the racemic mixture. The selectivity of the enzymes with respect to the substrate was also only weakly affected by the structure of the leaving alcohol except in the case of the iso-propyl group, which causes high steric hindrance. Operating conditions under reduced pressure were defined to resolve the racemic mixture with immobilized Rhizomucor miehei lipase.
- Guieysse, David,Salagnad, Christophe,Monsan, Pierre,Remaud-Simeon, Magali
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p. 2473 - 2480
(2007/10/03)
-
- Direct Carbonylation of Benzyl Alcohol and Its Analogs Catalyzed by Palladium and HI in Aqueous Systems and Mechanistic Studies
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Carbonylation of benzyl alcohol, benzyl formate, dibenzyl ether, and benzyl phenylacetate catalyzed by palladium complexes and promoted by hydrogen iodide gives phenylacetic acid in moderate to excellent yields in aqueous systems. Application of the carbonylation process to other arylmethanol analogs provides convenient means to prepare 2-naphthaleneacetic acid, 3-isochromanone, 1,4-benzenediacetic acid, and o-hydroxybenzeneacetic acid. A mechanism for the catalytic reaction is proposed, which involves (1) formation of benzyl iodide by the reaction of benzyl alcohol with HI in situ, (2) oxidative addition of benzyl iodide to palladium(0) to form a benzylpalladium iodide species. (3) CO insertion into the Pd-benzyl bond to form a (phenylacetyl)palladium iodide species. (4) reductive elimination of phenylacetyl iodide, and (5) its hydrolysis into phenylacetic acid. Evidence supporting the mechanism was obtained by examining the properties of benzyl- and (phenylacetyl)palladium iodide and chloride complexes. Formation of benzyl(carbonyl)palladium species and migratory insertion of the benzyl group to CO was confirmed by means of NMR at low temperature under high pressure.
- Lin, Yong-Shou,Yamamoto, Akio
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p. 723 - 734
(2007/10/03)
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- Palladium-catalyzed carbonylation of benzyl alcohol and its analogs promoted by HI in aqueous systems
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Carbonylation of benzyl alcohol catalyzed by a palladium(0) complex and promoted by hydrogen iodide gives phenylacetic acid in excellent yields in aqueous systems. The catalysis is proposed to proceed through a benzylpalladium species formed by the oxidative addition of benzyl iodide, produced in situ by the interaction of benzyl alcohol with HI, to a Pd(0) species. Application of the carbonylation process to other arylmethanol analogs provided convenient means to prepare 3-isochromanone, 1,4-benzenediacetic acid, 2-hydroxybenzeneacetic acid and 2-naphthaleneacetic acid.
- Lin, Yong-Shou,Yamamoto, Akio
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p. 3747 - 3750
(2007/10/03)
-
- Catalytic carbonylation of benzylic and allylic bromides by a rhodium zwitterionic complex under phase transfer catalysis conditions
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The zwitterionic rhodium complex, (COD)Rh(η6-C6H5BPh3) (1), can catalyze the carbonylation of benzylic and allylic bromides in the presence of 5 N NaOH and CH2Cl2 at atmospheric pressure and 40 deg C, with (C6H13)4N+ HSO4- as the phase transfer catalyst, to give carboxylic esters as the major products. Keywords: Rhodium; Carbonylation; Zwitterionic complex; Phase transfer catalysis
- Amaratunga, Shiyamalie,Alper, Howard
-
-
- A Study of the Ferrous Ion-initiated SRN1 Reactions of Halogenoarenes with tert-Butyl Acetate and N-Acylmorpholine Enolates
-
A detailed preparative study is reported of the ferrous ion-initiated SRN1 reactions of a range of halogenoarenes with the sodium enolates of tert-butyl acetate, n-acetylmorpholine and a number of higher N-acylmorpholines.Smooth and rapid substitution occurs in many cases, and good to excellent yields were obtained of arylacetic esters or acids, arylacetamides and arylalkanamides.The broad scope and limitations of the process have been defined, and the possible role of the ferrous ion is discussed.
- Leeuwen, Milko van,McKillop, Alexander
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p. 2433 - 2440
(2007/10/02)
-
- Process for producing optically active carboxylic acid
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A process for producing an optically active carboxylic acid represented by formula (I): STR1 wherein R1, and R2, and R3 each represents a hydrogen atom, an alkyl group, an alkenyl group, or a phenyl or naphthyl group which may have a substituent, provided that all of R1, R2, and R3 are not simultaneously a hydrogen atom; when R1 and R2 are simultaneously a hydrogen atom, then R3 is not a methyl group; and that when R3 is a hydrogen atom, then R1 and R2 are each a group other then a hydrogen atom, is disclosed, comprising asymmetrically hydrogenating an α,β-unsaturated carboxylic acid represented by formula (II): STR2 wherein R1, R2, and R3 are the same as defined above, in the presence of a ruthenium-optically active phosphine complex as a catalyst. According to the process of the invention, the desired optically active carboxylic acids which can be widely used as raw materials for synthesizing various useful compounds, for example, as intermediates for synthesizing physiologically active substances of natural materials and also as liquid crystal materials can be industrially advantageously produced.
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-
- Cobalt carbonyl catalyzed carbonylation of benzal bromides by phase transfer catalysis
-
The reaction of benzal bromides with CO (1 atm) in a binary system (aq.KOH/C6H6) in the presence of a catalytic amount of Co2(CO)8 together with benzyltriethylammonium chloride as a phase transfer catalyst for 8 h at room temperature gives the corresponding carboxylic acids in good to excellent yields.
- Shim, Sang Chul,Doh, Chil Hoon,Park, Woo Hyun,Kwon, Young Gil,Lee, Hyung Soo
-
p. 419 - 421
(2007/10/02)
-
- Lanthanide-Promoted and Nickel Cyanide Catalyzed Carbonylation Reactions under Phase-Transfer Conditions
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The nickel cyanide and phase transfer catalyzed carbonylation of benzyl chlorides is promoted by lanthanide salts .This simple reaction is sensitive to the concentration of the lanthanide compound, sodium hydroxide, quaternary ammonium salt, and nickel catalyst.The nature of the organic phase and phase transfer agent also influences the reaction rate.The acceleration of the reaction may be a consequence of coordination of a nickel cyanide nitrogen lone pair to the lanthanide salt.
- Amer, Ibrahim,Alper, Howard
-
p. 927 - 930
(2007/10/02)
-
- SYNTHETIC METHODS. PART 23. REARRANGEMENT OF SOME HYDROXAMIC ACIDS INTO AMIDES. A SELF-CONDENSATION LEADING TO DISPROPORTIONATION
-
Pyruvic acids have been shown to react with p-nitroso-N,N-dimethylaniline (1) to produce p-dimethyl-aminoacetanilides (3) via the corresponding hydroxamic acids (4).Three such intermediates (4a, c, d) have been isolated and their structure proved by n.m.r. and mass spectroscopy and elemental analysis.Solutions of the hydroxamic acids (4) have been shown to undergo concentration-dependent self-condensation and disproportionation leading to the amides (3) and acids (5).Rational pathways for these transformations are discussed.Spectral correlations permit differentiation between the amides (3) and the corresponding hydroxamic acids (4).
- Hassner, Alfred,Ruse, Margareta,Gottlieb, Hugo E.,Cojocaru, Miriam
-
p. 733 - 738
(2007/10/02)
-
- Poly(ethylene glycol) Promoted Reactions of Vinylic Dibromides. Dehydrohalogenation and Palladium(0)-Catalyzed Formal Oxidative Homologation
-
Aldehydes are converted to the homologous acids by a simple two-step procedure involving initial generation of a vinylic dibromide followed by Pd(diphos)2 catalyzed, poly(ethylene glycol) induced reaction with base.This reaction is useful for aromatic and α,β-unsaturated aldehydes and is also applicable to cyclic as well as alkyl aryl ketones. 1-Bromoalkynes are formed in good yields when the vinylic dibromide reaction is effected in the absence of the palladium(0) catalyst.
- Li, Pei,Alper, Howard
-
p. 4354 - 4356
(2007/10/02)
-
- Facile Cleavage of Bibenzyls by Cs-K-Na Alloy Leading to the Formation of Benzyl Carbanions
-
Facile cleavage of twelve substituted bibenzyls (1-12) with Cs-K-Na alloy at -75 deg C leading to the formation of benzyl carbanions has been studied.
- Sengupta, Dibyendu,Grovenstein, E.
-
p. 185 - 186
(2007/10/02)
-
- CATALYTIC PHASE TRANSFER CARBONYLATION OF BENZYL HALIDES WITH IRON PENTACARBONYL.
-
Benzyl halides are readily carbonylated to arylacetic acids in a two-phase system (aqueous sodium hydroxide (1M), tetrabutylammonium sulfate ; organic phase (CH2Cl2 or C6H6 or C6H5CH3)), using a catalytic amount of the cheap, easy to handle iron pentacarbonyl under carbon monoxide atmosphere.
- Tanguy, Guy,Weinberger, Berndt,Abbayes, Herve des
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p. 4005 - 4008
(2007/10/02)
-
- Carbanions. 23. Cleavage of 1,2-Diphenylethane and Derivatives by Cs-K-Na Alloy. Cometitive Rates of Bond Scission
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The following hydrocarbons are cleaved at a C-C bond to allylic and or/benzylic cesium compounds within 2 h by Cs-K-Na alloy in THF at -75 deg C: meso-2,3-diphenylbutane, 2,3-dimethyl-2,3-diphenylbutane, 1,2,2-triphenylpropane, 4-phenyl-1-butene, bibenzyl, and eight o-,m-, or p-methyl derivatives of bibenzyl.Under the same conditions 2-methyl- and 3-methyl-4-phenyl-1-butene were partially cleaved, 4,4'-dimethylbibenzyl was only slightly cleaved, and 9,10-dihydrophenanthrene was not detectably cleaved, while 10,11-dihydro-5H-dibenzocycloheptene underwent alternative C-H bond cleavage.Under the present reaction conditions 4,4'-dimethylbibenzyl and 9,10-dihydrophenanthrene were converted largely to dianions.It is suggested that all of the compounds undergoing cleavage are converted to dianions prior to cleavage.From competitive experiments the rates of reductive cleavage of most of these hydrocarbons relative to bibenzyl have been measured at -75 deg C.The relative rates of cleavage of m- and p-methylderivatives of bibenzyl may be correlated with the relative equilibrium acidities of toluene, m-xylene, and p-xylene in a modified Hammett relationship.Cleavages of benzylic C-C bonds are believed to occur by way of a preferred transition-state geometry,7, which permits the ?* orbital of the bond undergoing cleavage to interact with the HOMO's of both aromatic rings.Compounds that cannot attain this transition-state geometry are cleaved slowly if at all.The variable effect upon reaction rate of methyl groups near the bond undergoing cleavage are discussed in terms of ground-state and transition-state atrain, solvation, and polarizability of methyl groups.According to labeling experiments (o-methylbenzyl)cesium undergoes ready intramolecular sigmatropic migration of hydrogen from the methyl group to the methylene group when warmed from -75 deg C to near room temperature.
- Grovenstein, Erling,Bhatti, Amjad M.,Quest, Dean E.,Sengupta, Dibyendu,VanDerveer, Don
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p. 6290 - 6299
(2007/10/02)
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- PHASE TRANSFER CATALYSIS USING COBALT TRICARBONYL NITROSYL
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The first example of the use a mononuclear cobalt complex in a phase-transfer catalyzed process is described.The carbonylation of halides catalyzed by cobalt tricarbonyl nitrosyl gives, depending on the organic substrate, appreciably different results as compared with dicobalt octacarbonyl.
- Gambarotta, Sandro,Alper, Howard
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p. C23 - C26
(2007/10/02)
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