- Visible-light photoredox-catalyzed selective carboxylation of C(sp3)?F bonds with CO2
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It is highly attractive and challenging to utilize carbon dioxide (CO2), because of its inertness, as a nontoxic and sustainable C1 source in the synthesis of valuable compounds. Here, we report a novel selective carboxylation of C(sp3)?F bonds with CO2 via visible-light photoredox catalysis. A variety of mono-, di-, and trifluoroalkylarenes as well as α,α-difluorocarboxylic esters and amides undergo such reactions to give important aryl acetic acids and α-fluorocarboxylic acids, including several drugs and analogs, under mild conditions. Notably, mechanistic studies and DFT calculations demonstrate the dual role of CO2 as an electron carrier and electrophile during this transformation. The fluorinated substrates would undergo single-electron reduction by electron-rich CO2 radical anions, which are generated in situ from CO2 via sequential hydride-transfer reduction and hydrogen-atom-transfer processes. We anticipate our finding to be a starting point for more challenging CO2 utilization with inert substrates, including lignin and other biomass.
- Bo, Zhi-Yu,Chen, Lin,Gao, Tian-Yu,Jing, Ke,Lan, Yu,Liu, Shi-Han,Luo, Shu-Ping,Yan, Si-Shun,Yu, Bo,Yu, Da-Gang
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supporting information
p. 3099 - 3113
(2021/11/16)
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- Desulfonylative Electrocarboxylation with Carbon Dioxide
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Electrocarboxylation of organic halides is one of the most investigated electrochemical approaches for converting thermodynamically inert carbon dioxide (CO2) into value-added carboxylic acids. By converting organic halides into their sulfone derivatives, we have developed a highly efficient electrochemical desulfonylative carboxylation protocol. Such a strategy takes advantage of CO2as the abundant C1 building block for the facile preparation of multifunctionalized carboxylic acids, including the nonsteroidal anti-inflammatory drug ibuprofen, under mild reaction conditions.
- Zhong, Jun-Song,Yang, Zi-Xin,Ding, Cheng-Lin,Huang, Ya-Feng,Zhao, Yi,Yan, Hong,Ye, Ke-Yin
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supporting information
p. 16162 - 16170
(2021/09/02)
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- Relative activity of metal cathodes towards electroorganic coupling of CO2 with benzylic halides
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Electrochemical reduction of benzylic halides represents a convenient route to generating carbanions for their subsequent coupling with CO2 to obtain various carboxylic acids. Despite the industrial prospects of this synthetic process, it still lacks systematic studies of the efficient catalysts and reaction media design. In this work, we performed a detailed analysis of the catalytic activity of a series of different metal electrodes towards electroreduction of benzylic halides to corresponding radicals and carbanions using cyclic voltammetry. Specifically, we screened and summarized the performance of 12 bulk metal cathodes (Ag, Au, Cu, Pd, Pt, Ni, Ti, Zn, Fe, Al, Sn, and Pb) and 3 carbon-based materials (glassy carbon, carbon cloth, and carbon paper) towards electrocarboxylation of eight different benzylic halides and compare it to direct CO2 reduction in acetonitrile. Extensive experimental studies along with a detailed analysis of the results allowed us to map specific electrochemical properties of different metal electrodes, i.e., the potential zones related to the one- and two-electron reduction of organic halides as well as the potential windows where the electrochemical activation of CO2 does not occur. The reported systematic analysis should facilitate the development of nanostructured electrodes based on group 10 and 11 transition metals to further optimize the efficiency of electrocarboxylation of halides bearing specific substituents and make this technology competitive to current synthetic methods for the synthesis of carboxylic acids.
- Engelhardt, Helen,Klinkova, Anna,Medvedev, Jury J.,Medvedeva, Xenia V.
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- Oxidation of Alkynyl Boronates to Carboxylic Acids, Esters, and Amides
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A general efficient protocol was developed for the synthesis of carboxylic acids, esters, and amides through oxidation of alkynyl boronates, generated directly from terminal alkynes. This protocol represents the first example of C(sp)?B bond oxidation. This approach displays a broad substrate scope, including aryl and alkyl alkynes, and exhibits excellent functional group tolerance. Water, primary and secondary alcohols, and amines are suitable nucleophiles for this transformation. Notably, amino acids and peptides can be used as nucleophiles, providing an efficient method for the synthesis and modification of peptides. The practicability of this methodology was further highlighted by the preparation of pharmaceutical molecules.
- Li, Chenchen,Li, Ruoling,Zhang, Bing,Zhao, Pei,Zhao, Wanxiang
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supporting information
p. 10913 - 10917
(2020/05/25)
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- Method for converting benzyl borate compounds into phenylacetic acid and derivatives thereof by carbon dioxide
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The invention discloses a method for converting benzyl borate compounds into phenylacetic acid and derivatives thereof by carbon dioxide. The method comprises the steps: dissolving the benzyl borate compounds and an alkali in an organic solvent in the absence of a metal catalyst, introducing carbon dioxide into the reaction system, carrying out a reaction at the temperature of 50-150 DEG C for 3-72 hours, and acidifying to obtain phenylacetic acid or the derivatives thereof. The method is a green, simple and efficient method for synthesizing phenylacetic acid and the derivatives thereof, greenhouse gas carbon dioxide is used as a carbon source in the reaction, no transition metal catalyst is used, and the method is environmentally friendly, economical and high in efficiency.
- -
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Paragraph 0042-0043
(2020/03/06)
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- Pd(OH)2/C, a Practical and Efficient Catalyst for the Carboxylation of Benzylic Bromides with Carbon Monoxide
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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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- Preparation method of acid with different substituent groups
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The invention discloses a preparation method of an acid with different substituent groups. A terminal alkyne is lithiated with n-butyllithium, and then reacts with isopropoxyboronic acid pinacol ester, hydrogen chloride is added to achieve quenching, then the obtained reaction product is oxidized by an oxidizing agent, and the oxidized reaction product is separated and purified to obtain the acid.The method of the invention has the advantages of simplicity in operation, one-pot process preparation, no metal catalysis, nontoxic reagents, greenness, environmental friendliness and high atomic utilization rate, and provides a novel and quick way for preparing the acid with different substituent groups; and the obtained acid is an important fine chemical product, and can be widely used in fields of medicines, pesticides, spices and other industries.
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Paragraph 0048-0052
(2019/10/23)
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- Preparation method of phenylacetic acid type compound
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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 0122; 0123; 0124; 0131-0133
(2019/02/21)
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- Visible-Light-Driven External-Reductant-Free Cross-Electrophile Couplings of Tetraalkyl Ammonium Salts
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Cross-electrophile couplings between two electrophiles are powerful and economic methods to generate C-C bonds in the presence of stoichiometric external reductants. Herein, we report a novel strategy to realize the first external-reductant-free cross-electrophile coupling via visible-light photoredox catalysis. A variety of tetraalkyl ammonium salts, bearing primary, secondary, and tertiary C-N bonds, undergo selective couplings with aldehydes/ketone and CO2. Notably, the in situ generated byproduct, trimethylamine, is efficiently utilized as the electron donor. Moreover, this protocol exhibits mild reaction conditions, low catalyst loading, broad substrate scope, good functional group tolerance, and facile scalability. Mechanistic studies indicate that benzyl radicals and anions might be generated as the key intermediates via photocatalysis, providing a new direction for cross-electrophile couplings.
- Liao, Li-Li,Cao, Guang-Mei,Ye, Jian-Heng,Sun, Guo-Quan,Zhou, Wen-Jun,Gui, Yong-Yuan,Yan, Si-Shun,Shen, Guo,Yu, Da-Gang
-
supporting information
p. 17338 - 17342
(2019/01/04)
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- Electrochemical direct carboxylation of benzyl alcohols having an electron-withdrawing group on the phenyl ring: One-step formation of phenylacetic acids from benzyl alcohols under mild conditions
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Electrochemical direct carboxylation of benzyl alcohols having an electron-withdrawing group on the phenyl ring was successfully carried out by constant current electrolysis using an undivided cell equipped with a platinum plate cathode and a magnesium rod anode in DMF in the presence of carbon dioxide. Reductive cleavage of the C-O bond followed by fixation of carbon dioxide efficiently took place at the benzylic position without any additive to give the corresponding phenylacetic acids in good yields in one step under neutral and mild conditions.
- Senboku, Hisanori,Yoneda, Kenji,Hara, Shoji
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p. 6772 - 6776
(2016/01/30)
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- The ketene-surrogate coupling: Catalytic conversion of aryl iodides into aryl ketenes through ynol ethers
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tert-Butoxyacetylene is shown to undergo Sonogashira coupling with aryl iodides to yield aryl-substituted tert-butyl ynol ethers. These intermediates participate in a [1,5]-hydride shift, which results in the extrusion of isobutylene and the generation of aryl ketenes. The ketenes are trapped in situ with multiple nucleophiles or undergo electrocyclic ring closure to yield hydroxynaphthalenes and quinolines.
- Zhang, Wenhan,Ready, Joseph M.
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supporting information
p. 8980 - 8984
(2014/11/07)
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- Ni-catalyzed carboxylation of C(sp2)- and C(sp3)-O bonds with CO2
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In recent years a significant progress has been made for the carboxylation of aryl and benzyl halides with CO2, becoming convenient alternatives to the use of stoichiometric amounts of well-defined metal species. Still, however, most of these processes require the use of pyrophoric and air-sensitive reagents and the current methods are mostly restricted to organic halides. Therefore, the discovery of a mild, operationally simple alternate carboxylation that occurs with a wide substrate scope employing readily available coupling partners will be highly desirable. Herein, we report a new protocol that deals with the development of a synergistic activation of CO2 and a rather challenging activation of inert C(sp2)-O and C(sp3)-O bonds derived from simple and cheap alcohols, a previously unrecognized opportunity in this field. This unprecedented carboxylation event is characterized by its simplicity, mild reaction conditions, remarkable selectivity pattern and an excellent chemoselectivity profile using air-, moisture-insensitive and easy-to-handle nickel precatalysts. Our results render our method a powerful alternative, practicality and novelty aside, to commonly used organic halides as counterparts in carboxylation protocols. Furthermore, this study shows, for the first time, that traceless directing groups allow for the reductive coupling of substrates without extended π-systems, a typical requisite in many C-O bond-cleavage reactions. Taking into consideration the limited knowledge in catalytic carboxylative reductive events, and the prospective impact of providing a new tool for accessing valuable carboxylic acids, we believe this work opens up new vistas and allows new tactics in reductive coupling events.
- Correa, Arkaitz,Leon, Thierry,Martin, Ruben
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supporting information
p. 1062 - 1069
(2014/02/14)
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- Phosphinoferrocene amidosulfonates: Synthesis, palladium complexes, and catalytic use in pd-catalyzed cyanation of aryl bromides in an aqueous reaction medium
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The reaction of pentafluorophenyl 1-(diphenylphosphino) ferrocene-1-carboxylate (4) with -aminosulfonic acids H2N(CH 2)nSO3H (n = 13) in the presence of 4-(dimethylamino)- pyridine and triethylamine affords the respective phosphinoferrocene amidosulfonates as crystalline triethylammonium salts, viz., (Et3NH)[Ph 2PfcCONH(CH2)nSO3] (1, n = 1; 2, n = 2; 3, n = 3; fc = ferrocene-1,1-diyl), in good yields. These ligands react smoothly with [PdCl2 (cod)] (cod = 2:2-cycloocta-1,5-diene) to give the anionic square-planar bis-phosphine complexes trans-(Et3NH)2- [PdCl2 (Ph2PfcCONH(CH2)nSO3-κP)2] (5, n = 1; 6, n = 2; and 7, n = 3). The chloride-bridged dimer [LNCPdCl]2, where LNC is 2-[(dimethylamino- κN)methyl]phenyl-κC1 auxiliary ligand, is cleaved with 1 to give (Et3NH)[LNCPd(Ph2PfcCONHCH2SO3-κP)] (8), in which the amidosulfonate coordinates as a simple phosphine. A similar reaction of [LNCPd(OAc)] 2 and 1 proceeds under a partial elimination of (Et3NH)OAc to afford a mixture of zwitterionic bis-chelate [LNCPd(Ph 2PfcCONHCH2SO3-κ2O,P)] (9) and another Pd(II) complex tentatively formulated as [LNCPd(OAc)- (Ph 2PfcCONHCH2SO3-κP)] (9a), from which the former complex separates as an analytically pure crystalline solid. All compounds have been characterized by spectroscopic methods and elemental analysis. The crystal structures of 1, 3, 52.5CH2Cl2, and 92CHCl3 were determined by single-crystal X-ray diffraction analysis. In addition, complexes 57 were tested as defined precatalysts for Pd-catalyzed cyanation of aryl bromides with K4[Fe(CN)6]3H2O in aqueous dioxane. Complex 5 proved the most active and generally applicable, affording the nitrile products in good to excellent yields.
- I Schulz, Jir,Cisarova, Ivana,Stepnicka, Petr
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experimental part
p. 729 - 738
(2012/03/22)
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- Electrochemical carboxylation of benzylic carbonates: Alternative method for efficient synthesis of arylacetic acids
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Electrochemical carboxylation of benzylic carbonates was successfully performed as an alternative method for the synthesis of phenylacetic acids by using a one-compartment cell equipped with a Pt plate cathode and an Mg rod anode in CH3CN to afford the corresponding phenylacetic acids in good yields.
- Ohkoshi, Masashi,Michinishi, Jun-Ya,Hara, Shoji,Senboku, Hisanori
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experimental part
p. 7732 - 7737
(2010/10/21)
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- METALLOPROTEASE INHIBITORS
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The present invention relates to amide containing aromatic MMP inhibiting compounds with a mono-amide heteroaromatic group, of formulas I and II:
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Page/Page column 79
(2008/06/13)
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- HYDRAZONE DERIVATIVE
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A compound represented by the following formula (I): wherein R1 represents hydrogen, aryl which may have a substituent, a saturated or unsaturated 5- to 7-membered heterocyclic group which may have a substituent, etc.; R2 represents hydrogen, aryl which may have a substituent, a saturated or unsaturated 5- to 7-membered heterocyclic group which may have a substituent, etc.; R3 represents hydrogen, etc.; Ar represents a divalent group derived from aromatic hydrocarbon, etc.; X represents a single bond, linear or branched alkylene having from 1 to 3 carbon atoms which may have a substituent, etc.; and G represents halogen, a saturated or unsaturated 5- or 6-membered cyclic hydrocarbon group which may have a substituent, a saturated or unsaturated 5- to 7-membered heterocyclic group which may have a substituent, etc., a salt thereof or a solvate thereof; and an agent for inhibiting aggregation and/or deposition of an amyloid protein or an amyloid-like protein, which comprises the compound, a salt thereof or a solvate thereof
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Page/Page column 46
(2010/11/08)
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- 2-QUINOXALINONE DERIVATIVES AS BRADYKININ ANTAGONISTS AND NOVEL COMPOUNDS
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2-Quinoxalinone derivatives are bradykinin B1 antagonists or inverse agonists useful in the treatment or prevention of symptoms such as pain and inflammation associated with the bradykinin B1 pathway.
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Page/Page column 13
(2010/02/10)
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- NOVEL QUINOXALINONE DERIVATIVES AS BRADYKININ B1 ANTAGONISTS
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2-Quinoxalinone derivatives are bradykinin B1 antagonists or inverse agonists useful in the treatment or prevention of symptoms such as pain and inflammation associated with the bradykinin B1 pathway.
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Page/Page column 24
(2010/02/07)
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- CHEMICAL ENCODING TECHNOLOGY FOR COMBINATORIAL SYNTHESIS
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A chemical tag can include a core and a plurality of substituents attached directly to the core. The substituents of each chemical tag form a subset of a closed set of possible substituents. The tag can be used to track an object.
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- AMINO ACID DERIVATIVES, PHARMACEUTICAL COMPOSITIONS CONTAINING THESE COMPOUNDS AND PROCESSES FOR PREPARING THEM
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The invention relates to new amino acid derivatives of general formula (I), wherein B, T, Z, Y, V and n are defined as in claim 1, the tautomers, diastereomers and enantiomers thereof, the mixtures thereof and the salts thereof, particularly their physiologically acceptable salts with inorganic or organic acids or bases which have valuable pharmacological properties, particularly selective NPY-antagonist properties, pharmaceutical compositions containing these compounds, the use thereof and processes for preparing them.
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- 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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- Antithrombotic quinoxazolines
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Quinoxazolines having antithrombotic activity. Exemplary of those disclosed are: 4-{[6-(N-carboxymethyl-quinolin-8-yl-sulphonylamino)-1-methyl-2-oxo-1,2-dihydroquinoxalin-3-yl]-methyl}-benzamidine, 4-{[6-(1-(N-cyclopentyl-carboxymethylcarbonylamino)-cyclo-propyl)-1-methyl-2-oxo-1,2-dihydroquinoxalin-3-yl]-methyl}-benzamidine, and 4-{[7-(N-carboxymethylaminocarbonyl-ethylamino)-4-methyl-quinolin-2-yl]-oxo}-benzamidine.
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- Synthesis of phenylacetic acids under rhodium-catalyzed carbonylation conditions
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Benzyl halides are efficiently carbonylated to phenylacetic acids in the presence of a catalytic amount of the dimer of chloro(1,5-cyclooctadiene)rhodium(I) in formic acid. Under these reaction conditions, sensitive functionalities such as esters and nitriles are tolerated and the phenylacetic acids are obtained in good to high yields. (C) 2000 Elsevier Science Ltd.
- Giroux,Nadeau,Han
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p. 7601 - 7604
(2007/10/03)
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- Amino acid derivatives, pharmaceutical compositions containing these compounds and processes for preparing them
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NPY-antagonistic compounds of the formula STR1 Exemplary are: (A) (R)-N-[[4-(Aminocarbonylaminomethyl)phenyl]methyl]-N 2-bis(4-hydroxyphenyl)acetyl]-argininamide-trifluoracetate;(B) (R)-N-[[4-(Aminocarbonylaminomethyl)phenyl]methyl]-N 2-[bis(4-chlorphenyl)acetyl]-argininamide-trifluoracetate;(C) (R)-N-[[4-Aminocarbonylaminomethyl)phenyl]methyl]-N 2-(diphenylacetyl)-argininamide-trifluoracetate;(D) (R)-N 2-(Diphenylacetyl)-N-[[4-(ethoxycarbonylmethylamino-carbonylaminomethyl) phenyl]methyl]-argininamide-trifluoroacetate;(E) (R,S)-N 5-(Aminoiminomethyl)-N 2-(diphenylacetyl)-N-[(4-hy-droxyphenyl)methyl]-N 5-methyl-ornithinamide-hydrochloride; (F) (R)-N-[[4-(Aminocarbonylmethyl)phenyl]methyl]-N 2-(diphenyl-acetyl)-argininamide-diacetate;(G) (R)-N. sup. 2-(Diphenylacetyl)-N-[[4-(ethylaminocarbonylamino-methyl)-phenyl]methyl]-argininamide-bis-(trifluoroacetate); and,(H) (R)-N. sup.2-(Diphenylacetyl)-N-[[4-(ethoxycarbonylamino-carbonylaminomethyl) phenyl]methyl]-argininamide-trifluoroacetate.
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- Rationalisation of the regioselective hydrolysis of aliphatic dinitriles with Rhodococcus rhodochrous AJ270
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Aliphatic dinitriles undergo regioselective hydrolysis with the title organism to give monoacids with up to four methylenes between the nitrile functions (optimally 2-3) or when either an oxygen is placed β, γ or δ to the nitrile (δ-placement being optimal) or β or γ (optimally γ) but not δ sulfur substituents are present; nitrogen substituents appear to behave as for oxygen but suffer a steric limitation of the size of the nitrogen substituent.
- Meth-Cohn, Otto,Wang, Mei-Xiang
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p. 1041 - 1042
(2007/10/03)
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- Regioselective biotransformations of dinitriles using Rhodococcus sp. AJ270
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A variety of dinitriles have been hydrolysed selectively under very mild conditions using Rhodococcus sp. AJ270. Aliphatic dinitriles NC[CH2]nCN 1 undergo regioselective hydrolysis to give the mono acids 2 with up to 4 methylenes between the nitrile functions while those with n > 4 give the diacids 3 in good yield. Dinitriles NC[CH2]nX[CH2]nCN 4 bearing an ether or sulfide linkage are efficiently transformed into the mono acids 5 when an oxygen is placed β, γ or δ to the cyano group or a β- or γ-sulfur is present. Hydrolysis of N,N-bis(2-cyanoethyl)anilines 4h-j takes place slowly affording exclusively the monoacids 5h-j while the monocyano amides 5o-p are obtained as the sole isolable product from rapid hydrolysis of the corresponding N,N-bis(2-cyanomethyl)butylamine 4o and N,N-bis(3-cyanopropyl)butylamine 4p. Higher homologues of arylimino- and butylimino-dinitriles are inert to enzymatic hydrolysis. A variety of other aliphatic dinitriles have been converted readily into mono acids in good to excellent yields except for o-phenylenediacetonitrile which gives o-phenylenediacetamide as the major product. The title organism also effects the hydrolysis of aromatic dinitriles with regiocontrol such as m- and p-dicyanobenzenes, but nct the ortho-substituted analogue. The scope and limitations of this enzymatic process have been systematically studied and the mechanism of regioselective hydrolysis has been discussed in terms of a chelation-deactivation effect.
- Meth-Cohn, Otto,Wang, Mei-Xiang
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p. 3197 - 3204
(2007/10/03)
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- Photolysis of the 1-naphthylmethyl ester of substituted phenylacetic acids: intramolecular charge transfer and rates of decarboxylation of arylacyl radicals
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The photolysis of esters 6 and 8 in methanol leads to products resulting from both naphthylmethyl cations and radicals.The product distribution is nearly independent of X for the esters 6 except when X equals methoxy.A mechanism involving initial homolytic cleavage of the carbon-oxygen bond in the excited singlet state of the ester is proposed.Competition between electron transfer in the radical pair to form the ion pair and decarboxylation of the arylacyloxy radical allows calculations of the rates of this decarboxylation process.The ρ values versus ? is close to zero.When X equals methoxy, intramolecular electron transfer occurs with the naphthalene ring serving as the acceptor and the methoxyaromatic as the donor.This exciplex fragments to carbon dioxide and 1-(1-naphthyl)-2-arylethane. Key words: acyloxy radical, decarboxylation, photolysis of benzylic esters.
- Hilborn, James W.,Pincock, James A.
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p. 992 - 999
(2007/10/02)
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