- Transition-Metal-Free DMAP-Mediated Aromatic Esterification of Amides with Organoboronic Acids
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A new, transition-metal-free, effective method for aromatic esterification of amides with organoboronic acids has been developed. A wide range of benzoate derivatives were obtained with yields ranging from moderate to good. The catalytic reaction shows a broad substrate scope and excellent functional group tolerance. Conceptually, DMAP mediates the reaction and is crucial for this transformation.
- Guo, Jiarui,Liu, Lantao,Wang, Tao,Wang, Yanqing,Xu, Kai,Zhang, Yuheng
-
supporting information
p. 3274 - 3277
(2021/06/26)
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- Electro-Oxidative Selective Esterification of Methylarenes and Benzaldehydes
-
A mild and green electro-oxidative protocol to construct aromatic esters from methylarenes and alcohols is herein reported. Importantly, the reaction is free of metals, chemical oxidants, bases, acids, and operates at room temperature. Moreover, the design of the electrolyte was found critical for the oxidation state and structure of the coupling products, a rarely documented effect. This electro-oxidative coupling process also displays exceptional tolerance of many fragile easily oxidized functional groups such as hydroxy, aldehyde, olefin, alkyne, as well as neighboring benzylic positions. The enantiomeric enrichment of some chiral alcohols is moreover preserved during this electro-oxidative coupling reaction, making it overall a promising synthetic tool.
- Yu, Congjun,?zkaya, Bünyamin,Patureau, Frederic W.
-
supporting information
p. 3682 - 3687
(2021/02/01)
-
- Nickel-Catalyzed Esterification of Amides Under Mild Conditions
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Abstract: The use of ligands to adjust the catalytic activity of the catalyst for esterification of amides is challenge in organic chemistry. In this paper, Nickel(II)-NHC-catalyzed the esterification reaction between N,N-di-Boc amide and alcohols at room temperature have been demonstrated. The imidazolium salt bearing a hydroxyl functionalized side arm showed high effective catalytic activity in the activation of the amide N–C bond in air atmosphere. Graphic Abstract: [Figure not available: see fulltext.].
- Li, Jun-Fei,Wang, Yao-Fang,Wu, Yuan-Yuan,Liu, Wen-Jing,Wang, Jun-Wen
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p. 874 - 880
(2019/11/13)
-
- Quinolin-8-yl Formate: A New Option for Small-Scale Carbonylation Reactions in Microwave Reactors
-
A convenient procedure for conducting small-scale carbonylations of aryl or benzyl halides in a microwave reactor by using quinolin-8-yl formate is described. The resulting 8-acyloxyquinolines were shown to be more reactive than phenyl esters in acyl-tran
- Maddocks, Christopher J.,Aathimanikandan, Sivakumar V.,Richardson, Jeffery,Ruble, J. Craig
-
p. 1608 - 1612
(2020/09/09)
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- Mechanochemical Palladium-Catalyzed Carbonylative Reactions Using Mo(CO)6
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Esters and amides were mechanochemically prepared by palladium-catalyzed carbonylative reactions of aryl iodides by using molybdenum hexacarbonyl as a convenient solid carbonyl source and avoiding a direct handling of gaseous carbon monoxide. Real-time monitoring of the mechanochemical reaction by in situ pressure sensing revealed that CO is rapidly transferred from Mo(CO)6 to the active catalytic system without significant release of molecular carbon monoxide.
- van Bonn, Pit,Bolm, Carsten,Hernández, José G.
-
p. 2576 - 2580
(2020/02/20)
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- A Cyanide-Free Synthesis of Acylcyanides through Ru-Catalyzed C(sp3)-H-Oxidation of Benzylic Nitriles
-
A practical method for generation of acylcyanides devoid of any external cyanide sources is presented that relies on a mild Ru-catalyzed selective C?H-oxidation of benzylic nitriles. The starting materials are smoothly generated through condensation of the corresponding carboxylic acid amides using silanes. The obtained acylcyanides can be employed in a plethora of transformation as exemplified to some larger extend in the sequence of C?H-oxidation-Tischenko-rearrangement for the generation of structurally diverse benzoyloxycyanohydrines.
- Eisele, Pascal,Bauder, Michael,Hsu, Shih-Fan,Plietker, Bernd
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p. 689 - 691
(2019/05/07)
-
- Carbon monoxide is used as a source of halogen compound heterogeneous palladium catalyst in the presence of the aldehyde carbonyl compound by reaction carbonylation method (by machine translation)
-
[Problem] catalyst and the presence of carbon monoxide, the halogen compound is a carbonyl compound in the carbonylation reaction, catalysts or carbon monoxide source technique has problems. [Solution] the presence of the catalyst and the carbon monoxide, the halogen compound is carbonylation reaction method for producing a carbonyl compound, As a heterogeneous palladium catalyst, carbon monoxide is produced from an aldehyde carbonyl compound used in the method. [Drawing] no (by machine translation)
- -
-
Paragraph 0066; 0067; 0068
(2018/04/06)
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- Phosphite-catalyzed alkoxycarbonylation of aryl diazonium salts
-
In this communication, an interesting phosphite-catalyzed alkoxycarbonylation of aryl diazonium salts has been reported. At room temperature and under CO pressure, moderate to good yields of the desired esters can be produced in the absence of bases or an
- Xu, Jian-Xing,Franke, Robert,Wu, Xiao-Feng
-
supporting information
p. 6180 - 6182
(2018/09/10)
-
- Efficient synthesis of esters through oxone-catalyzed dehydrogenation of carboxylic acids and alcohols
-
Since esters are important organic synthesis intermediates, an environmentally friendly oxone catalyzed-esterification of carboxylic acids with alcohols has been developed. A series of carboxylic acid esters are obtained in high yield. This strategy requires mild reaction conditions, providing an attractive alternative for the construction of valuable carbonyl esters. Electron-rich and electron-deficient groups are compatible with the standard conditions and a variety of substrates are demonstrated. Moreover, the reaction could easily be adapted to typical prodrugs, drugs and gram-scale synthesis.
- Hou, Fei,Wang, Xi-Cun,Quan, Zheng-Jun
-
supporting information
p. 9472 - 9476
(2019/01/03)
-
- Heterogeneous One-Pot Carbonylation and Mizoroki–Heck Reaction in a Parallel Manner Following the Cleavage of Cinnamaldehyde Derivatives
-
Carbon monoxide (CO) and styrene derivatives that can be both generated by a palladium on carbon (Pd/C)-catalyzed carbon–carbon (C?C) bond cleavage reaction of cinnamaldehyde derivatives were effectively utilized in further palladium-catalyzed C?C bond forming reactions in a direct and practical way. CO derived from simple and affordable CO carriers such as cinnamaldehyde or terephthalaldehyde was efficiently employed in the in situ CO fixation with various aromatic iodides through a palladium-catalyzed carbonylation followed by an inter- or intramolecular coupling reaction with alcohols to afford the corresponding esters or lactones, respectively. Styrene derivatives were also efficient substrates in an in situ Mizoroki–Heck-type cross-coupling reaction with aryl iodides, leading to the effective formation of asymmetric stilbenes. The decarbonylation of cinnamaldehyde derivatives and the subsequent independent syntheses of both esters/lactones and 1,2-diarylethenes could be achieved in a virtual one-pot and in situ reaction using a H-shaped pressure-tight glass-sealed tube consisting of two independent but laterally connected reaction tubes in the gas space.
- Hattori, Tomohiro,Ueda, Shun,Takakura, Ryoya,Sawama, Yoshinari,Monguchi, Yasunari,Sajiki, Hironao
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p. 8196 - 8202
(2017/06/23)
-
- Room Temperature Carbonylation of (Hetero) Aryl Pentafluorobenzenesulfonates and Triflates using Palladium-Cobalt Bimetallic Catalyst: Dual Role of Cobalt Carbonyl
-
An efficient method for the carbonylation of (hetero) aryl pentafluorobenzenesulfonates and triflates under exceptionally mild conditions using palladium/dicobalt octacarbonyl [Pd/Co2(CO)8] has been developed. Besides acting as carbon monoxide (CO) source, Co2(CO)8enhances the reaction rate by accelerating the CO insertion through an in situ generated bimetallic palladium cobalt tetracarbonyl [Pd-Co(CO)4] complex. Under the optimized reaction condition, carbonylation of a wide range of activated and deactivated, as well as sterically hindered and heteroaromatic, substrates proceeded efficiently at room temperature. The high chemoselectivity and improved synthesis of biologically relevant Isoguvacine and Lazabemide intermediates highlights its scope as a valuable synthetic method. The generality of this protocol was further extended to other electrophiles (bromides, chlorides and tosylates). (Figure presented.).
- Joseph, Jayan T.,Sajith, Ayyiliath M.,Ningegowda, Revanna C.,Shashikanth, Sheena
-
supporting information
p. 419 - 425
(2017/02/10)
-
- Cobalt-Catalyzed Esterification of Amides
-
The first cobalt-catalyzed amide activation of N-Boc-amides, and their conversion into esters, is reported here. This new methodology presents a very practical process that does not require an inert atmosphere, uses an inexpensive cobalt catalyst, and proceeds under mild reaction conditions. This catalytic system has a broad substrate scope and has been shown to be highly efficient, with catalyst loadings as low as 1 mol %.
- Bourne-Branchu, Yann,Gosmini, Corinne,Danoun, Grégory
-
p. 10043 - 10047
(2017/08/01)
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- Metal-free radical aromatic carbonylations mediated by weak bases
-
We report a new method of metal-free alkoxycarbonylation. This reaction involves the generation of aryl radicals from arenediazonium salts by a very weak base (HCO2Na) under mild conditions. Subsequent radical trapping with carbon monoxide and alcohols gives alkyl benzoates. The conditions (metal-free, 1 equiv. base, MeCN, r.t., 3 h) tolerate various functional groups (I, Br, Cl, CF3, SF5, NO2, ester). Mechanistic studies indicate the operation of a radical aromatic substitution mechanism.
- Koziakov, Denis,Jacobi Von Wangelin, Axel
-
supporting information
p. 6715 - 6719
(2017/08/22)
-
- Development and Applications of Transesterification Reactions Catalyzed by N-Heterocyclic Olefins
-
A novel method to utilize N-heterocyclic olefins (NHOs), the alkylidene derivatives of N-heterocycic carbenes, as organocatalysts to promote transesterification reactions has been developed. Because of their strong Br?nsted/Lewis basicity, NHOs can enhance the nucleophilicity of alcohols for their acylation reactions with carboxylic esters. This transformation can be employed in industrially relevant processes such as the production of biodiesel, the depolymerization of polyethylene terephthalate (PET) from plastic bottles for recycling purposes, and the ring-opening polymerization of cyclic esters to form biodegradable polymers such as polylactide (PLA) and polycaprolactone (PCL).
- Blümel, Marcus,Noy, Janina-Miriam,Enders, Dieter,Stenzel, Martina H.,Nguyen, Thanh V.
-
supporting information
p. 2208 - 2211
(2016/06/01)
-
- Synthetic method of an ester compound
-
The invention discloses a synthetic method of an ester compound and belongs to the technical field of organic synthesis. The synthetic method includes the steps of: dissolving an aldehyde compound (1) and a halogenated hydrocarbon compound (2) in a solvent, adding an oxidant and a catalyst, and performing a reaction at 60-100 DEG C to obtain the target product ester compound (3). A reaction equation of the synthetic method is represented as follows. The method, compared with the prior art, has the following advantages: 1) the raw materials are easy to obtain and are low in cost; 2) the reaction conditions are mild, operations are simple, and reaction time is short; and 3) a substrate has wide available range and can be used for synthesis of various ester compounds.
- -
-
Paragraph 0099; 0100; 0101
(2017/02/02)
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- Synthesis of Ketones and Esters from Heteroatom-Functionalized Alkenes by Cobalt-Mediated Hydrogen Atom Transfer
-
Cobalt bis(acetylacetonate) is shown to mediate hydrogen atom transfer to a broad range of functionalized alkenes; in situ oxidation of the resulting alkylradical intermediates, followed by hydrolysis, provides expedient access to ketones and esters. By modification of the alcohol solvent, different alkyl ester products may be obtained. The method is compatible with a number of functional groups including alkenyl halides, sulfides, triflates, and phosphonates and provides a mild and practical alternative to the Tamao-Fleming oxidation of vinylsilanes and the Arndt-Eistert homologation.
- Ma, Xiaoshen,Herzon, Seth B.
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p. 8673 - 8695
(2016/10/17)
-
- Appel reaction of carboxylic acids with tribromoisocyanuric acid/triphenylphosphine: A mild and acid-free preparation of esters and amides
-
A facile and efficient method for esterification and amidation of carboxylic acids under neutral conditions has been developed. Esters and amides can be prepared by reacting a carboxylic acid (1 mmol) with tribromoisocyanuric acid (0.37 mmol) and triphenylphosphine (1 mmol) in dichloromethane at room temperature, followed by addition of an alcohol or an amine, respectively.
- Da Cunha Sindra, Haryadylla,De Mattos, Marcio C.S.
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p. 1129 - 1136
(2016/07/06)
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- Chemoselective dehydrogenative esterification of aldehydes and alcohols with a dimeric rhodium(II) catalyst
-
Dehydrogenative cross-coupling of aldehydes with alcohols as well as dehydrogentive cross-coupling of primary alcohols to produce esters have been developed using a Rh-terpyridine catalyst. The catalyst demonstrates broad substrate scope and good functional group tolerance, affording esters highly selectively. The high chemoselectivity of the catalyst stems from its preference for dehydrogenation of benzylic alcohols over aliphatic ones. Preliminary mechanistic studies suggest that the active catalyst is a dimeric Rh(ii) species, operating via a mechanism involving metal-base-metal cooperativity.
- Cheng, Junjie,Zhu, Meijuan,Wang, Chao,Li, Junjun,Jiang, Xue,Wei, Yawen,Tang, Weijun,Xue, Dong,Xiao, Jianliang
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p. 4428 - 4434
(2016/07/07)
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- Transfer Hydrogenation of Nitriles, Olefins, and N-Heterocycles Catalyzed by an N-Heterocyclic Carbene-Supported Half-Sandwich Complex of Ruthenium
-
In the presence of KOBut, N-heterocyclic carbene-supported half-sandwich complex [Cp(IPr)Ru(pyr)2][PF6] (3) (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) catalyzes transfer hydrogenation (TH) of nitriles, activated N-heterocycles, olefins, and conjugated olefins in isopropanol at the catalyst loading of 0.5%. The TH of nitriles leads to imines, produced as a result of coupling of the initially formed amines with acetone (produced from isopropanol), and showed good chemoselectivity. Reduction of N-heterocycles occurs for activated polycyclic substrates (e.g., quinoline) and takes place exclusively in the heterocycle. The TH also works well for linear and cyclic olefins but fails for trisubstituted substrates. However, the C = C bond of α,β-unsaturated esters, amides, and acids is easily reduced even for trisubstituted species, such as isovaleriates. Mechanistic studies suggest that the active species in these catalytic reactions is the trihydride Cp(IPr)RuH3 (5), which can catalyze these reactions in the absence of any base. Kinetic studies are consistent with a classical inner sphere hydride-based mechanism of TH.
- Mai, Van Hung,Nikonov, Georgii I.
-
supporting information
p. 943 - 949
(2016/05/09)
-
- Metal-free, room-temperature, radical alkoxycarbonylation of aryldiazonium salts through visible-light photoredox catalysis
-
The first radical alkoxycarboxylation of aryldiazonium salts using CO gas through visible-light-induced photoredox catalysis (16 W blue LEDs) has been developed. This reaction is entirely metal-free, is carried out at room temperature with a low loading of an organic dye as a photocatalyst (0.5 mol%), and provides a wide range of arylcarboxylic acid esters in high yields. Importantly, this photocatalytic system can be successfully extended to other carboxylation reactions.
- Guo, Wei,Lu, Liang-Qiu,Wang, Yue,Wang, Ya-Ni,Chen, Jia-Rong,Xiao, Wen-Jing
-
supporting information
p. 2265 - 2269
(2015/02/19)
-
- Metal-free carbonylations by photoredox catalysis
-
The synthesis of benzoates from aryl electrophiles and carbon monoxide is a prime example of a transition-metalcatalyzed carbonylation reaction which is widely applied in research and industrial processes. Such reactions proceed in the presence of Pd or Ni catalysts, suitable ligands, and stoichiometric bases. We have developed an alternative procedure that is free of any metal, ligand, and base. The method involves a redox reaction driven by visible light and catalyzed by eosin Y which affords alkyl benzoates from arene diazonium salts, carbon monoxide, and alcohols under mild conditions. Tertiary esters can also be prepared in high yields. DFT calculations and radical trapping experiments support a catalytic photoredox pathway without the requirement for sacrificial redox partners.
- Majek, Michal,Von Wangelin, Axel Jacobi
-
supporting information
p. 2270 - 2274
(2015/02/19)
-
- Fe3O4 supported Pd(0) nanoparticles catalyzed alkoxycarbonylation of aryl halides
-
This paper describes the simple and efficient method for the alkoxycarbonylation of aryl iodides using magnetically recoverable Pd/Fe 3O4 as the catalyst under atmospheric pressure of carbon monoxide. Various aryl iodides on alkoxycarbonylation with alcohols gave the corresponding products in good to excellent yields. The catalyst is completely recoverable with the simple application of an external magnetic field, and the efficiency of the catalyst remains unaltered even after five cycles.
- Siva Prasad, Aviraboina,Satyanarayana, Bollikonda
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p. 205 - 209
(2013/04/23)
-
- Pd-catalyzed aldehyde to ester conversion: A hydrogen transfer approach
-
Aliphatic and aromatic aldehydes are successfully converted into their corresponding esters using Pd(OAc)2 and XPhos. This approach utilizes a hydrogen transfer protocol: concomitant reduction of acetone to isopropanol provides an inexpensive and sustainable approach that mitigates the need for other oxidants.
- Tschaen, Brittany A.,Schmink, Jason R.,Molander, Gary A.
-
supporting information
p. 500 - 503
(2013/04/11)
-
- Acylative cleavage of ethers with ZnCl2
-
Acylative cleavage of common ether solvents with ZnCl2 was reported. Different substituted acyl chlorides were reacted with the common ether solvents in the presence of ZnCl2 to obtain the corresponding substituted benzoate.
- Yu, Yun-Feng,Gao, Jian-Rong,Jiang, Shao-Liang,Han, Liang,Jia, Jian-Hong,Li, Yu-Jin
-
experimental part
p. 5199 - 5201
(2012/09/21)
-
- Facile preparation of aromatic esters from aromatic bromides with ethyl formate or DMF and molecular iodine via aryllithium
-
Various aromatic bromides were treated with n-BuLi and subsequently with ethyl formate, followed by the reaction with ethanol and molecular iodine in the presence of K2CO3 to provide the corresponding aromatic ethyl esters in good yields. Moreover, aromatic bromides could be transformed into the corresponding aromatic methyl esters in good yields by the treatment with n-BuLi and subsequently with DMF, followed by the reaction with methanol, molecular iodine, and K2CO3. Some aromatics could be also converted into the corresponding aromatic esters in good yields by the treatment with n-BuLi, and subsequently with ethyl formate or DMF, followed by the reaction with molecular iodine and K2CO3. The present reactions offer a novel route for the transition-metal-free, carbon-monoxide-free, and therefore environmentally benign one-pot conversion of aromatic bromides and aromatics into aromatic esters.
- Ushijima, Sousuke,Moriyama, Katsuhiko,Togo, Hideo
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experimental part
p. 4701 - 4709
(2012/07/28)
-
- Highly regioselective synthesis of 1,3-diiodonaphthalene derivatives via a sequential cascade iodocyclization
-
A novel and flexible sequentially cascade iodocyclization for the synthesis of highly substituted 1,3-diiodinated naphthalene derivatives in up to 99% yield under mild conditions is reported. The dihalogenated moiety can be readily introduced into the naphthalenes in a position that is usually not easily functionalized.
- Wang, Li-Jing,Zhu, Hai-Tao,Lu, Lei,Yang, Fang,Liu, Xue-Yuan,Liang, Yong-Min
-
experimental part
p. 1990 - 1993
(2012/06/01)
-
- Oxidative cross-esterification of dithiolanes with alcohols through a cross-dehydrogenative coupling (CDC)/deprotection sequence
-
An unprecedented oxidative cross-esterification in an equimolar mixture of dithiolanes, alcohols and water through a CDC/deprotection sequence has been developed. The reaction itself features simple experimental procedures under very mild conditions and offers a new strategic protocol for the direct and efficient synthesis of structurally diverse esters.
- Fu, Liang,Yao, Chang-Jiang,Chang, Ning-Jie,Chen, Jia-Rong,Lu, Liang-Qiu,Xiao, Wen-Jing
-
supporting information; experimental part
p. 506 - 508
(2012/01/15)
-
- Rhenium complex-catalyzed acylative cleavage of ethers with acyl chlorides
-
It was found that rhenium complex was an efficient catalyst for the acylative cleavage of C-O bond of ethers with acyl chlorides. When acyclic ethers were allowed to react with acyl chlorides in the presence of a catalytic amount of ReBr(CO)5, acylative cleavage of C-O bond of acyclic ethers smoothly proceeded to give the corresponding esters in moderate to good yields. Similarly, cyclic ethers were acylative cleaved by acyl chlorides to give the corresponding chloro substituted esters in good yields by the use of Re 2O7 catalyst.
- Umeda, Rui,Nishimura, Takashi,Kaiba, Kenta,Tanaka, Toshimasa,Takahashi, Yuuki,Nishiyama, Yutaka
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experimental part
p. 7217 - 7221
(2011/10/08)
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- Rhenium complex as a useful catalyst for acylative cleavage of ethers
-
It was found that a rhenium complex such as ReBr(CO)5 acts as an efficient catalyst for the acylative cleavage of the carbon-oxygen bond of ethers with acyl chloride, giving the corresponding esters in moderate to good yields.
- Umeda, Rui,Kaiba, Kenta,Tanaka, Toshimasa,Takahashi, Yuuki,Nishimura, Takashi,Nishiyama, Yutaka
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experimental part
p. 3089 - 3091
(2011/02/25)
-
- Base-induced mechanistic variation in palladium-catalyzed carbonylation of aryl iodides
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A mechanism, which is distinct from the traditional one when sodium alkoxide was used instead of tertiary amines, was proposed for the alkoxycarbonylation of aryl iodides. The catalytic cycle was composed of oxidative addition, subsequent ArPdOR formation, CO insertion to Pd-OR, and final reductive elimination of ArPdCOOR. The kinetic simultaneity of the formation of deiodinated side product from the aryl iodide and aldehyde from corresponding alcohol provided strong evidence for the existence of ArPdOR species. The observation of thioether, as the other competitive product in palladium catalyzed thiocarbonylation of aryl iodides and sodium alkylthiolate, also indicate the possibility of metathesis between ArPdl and sodium alkylthiolate. Preliminary kinetic studies revealed that neither oxidative addition nor reductive elimination was rate limiting. DFT calculation displayed preference for CO insertion into Pd-OR bond. The advantage of this novel mechanism had been demonstrated in the facile alkoxycarbonylation and thiocarbonylation. The ethoxycarbonylation of aryl iodides under room temperature and balloon pressure of CO in the presence of EtONa were examined, and good to high yields were obtained; the t-butoxycarbonylation reactions in the presence of t-BuONa were achieved, and the alkylthiocarbonylation (including the t-butylthiocarbonylation) of aryl iodides in the presence of sodium alkylthiolate were also investigated.
- Hu, Yanhe,Liu, Jing,Lu, Zhixin,Luo, Xiancai,Zhang, Heng,Lan, Yu,Lei, Aiwen
-
supporting information; experimental part
p. 3153 - 3158
(2010/05/15)
-
- Microwave-assisted carbonylation and cyclocarbonylation of aryl iodides under ligand free heterogeneous catalysis
-
"Chemical Equation Presented" Carbonylation reaction is a very effective transformation for the synthesis of esters, amides, and heterocyclic compounds. Heterogeneous catalyzed carbonylation reactions can be carried out using the association of Pd/C and microwave dielectric heating. Alkoxy carbonylation can be performed, with stoichiometric amounts of different primary and secondary alcohols in DMF in the presence of DBU as the base. Analogously, iodobenzene, CO, and amines can be transformed into the corresponding amides in good yields after a simple filtration to remove the catalyst. Pd/C was also successfully employed in microwave-assisted cyclocarbonylation of o-iodoaniline with acyl chlorides to give benzoxazinones. Pd/ C can be recycled two times without, a considerable difference in the reaction yields.
- Salvadori, Jessica,Balducci, Evita,Zaza, Silvia,Petricci, Elena,Taddei, Maurizio
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experimental part
p. 1841 - 1847
(2010/06/11)
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- Palladium-catalyzed aerobic oxidative carbonylation of arylboronate esters under mild conditions
-
(Figure Presented) "CO"n Air: The title reaction was carried out using [PdCl2(PPh3)2 ] as the catalyst precursor under very mild conditions (balloon pressure of CO and air, at 40- 50°C), and produced a wide range of aryl carboxyl esters 2 in good to excellent yields. Remarkable selectivity between oxidative carbonylation and homocoupling of arylboronate esters l was also achieved.
- Liu, Qiang,Li, Gang,He, Jun,Liu, Jing,Li, Peng,Lei, Aiwen
-
supporting information; experimental part
p. 3371 - 3374
(2010/07/06)
-
- 5H-3-oxa-Octafluoropentanesulfonyl fluoride: a novel and efficient condensing agent for esterification, amidation and anhydridization
-
The use of 5H-3-oxa-octafluoropentanesulfonyl fluoride (HCF2CF2OCF2CF2SO2F) as a novel and efficient condensing reagent for esterification of carboxylic acids with alcohols and amidation of carboxylic acids with amines in the presence of 1,3-diazabicyclo[5.4.0]-undec-7-ene (DBU) is reported. HCF2CF2OCF2CF2SO2F cannot serve as a condensing agent for anhydridization of carboxylic acids, however, HCF2CF2OCF2CF2SO2F/(CH3)3SiCN system can mediate anhydridization of some aromatic carboxylic acids.
- Yan, Zhaohua,Tian, Weisheng,Zeng, Fanrong,Dai, Yanfeng
-
experimental part
p. 2727 - 2729
(2009/09/06)
-
- Iron-catalyzed one-pot oxidative esterification of aldehydes
-
A highly efficient, mild, and simple protocol for Fe(ClO4) 3·xH2O-catalyzed oxidative esterification of aldehydes was developed. Several aromatic and aliphatic aldehydes reacted with simple primary and secondary alcohols, used as the solvent, smoothly in the presence of an iron salt catalyst (10 mol-%) and hydroperoxide (4 equiv.) as an oxidant to generate the corresponding esters in good to excellent yields. Wiley-VCH Verlag GmbH & Co. KGaA, 2009.
- Wu, Xiao-Feng,Darcel, Christophe
-
supporting information; experimental part
p. 1144 - 1147
(2009/07/11)
-
- Direct conversion of aromatic ketones to arenecarboxylic esters via carbon-carbon bond-cleavage reactions
-
Aromatic methyl ketones, ss-keto esters, and trifluoromethyl-l,3- diketones can be directly converted to arene-carboxylic esters via carbon-carbon bond cleavage of pyridinium iodide intermediates in the presence of copper(II) oxide, iodine, pyridine, and potassium carbonate in alcoholic media. The advantages of the present method in terms of good yields, mild reaction conditions, and inexpensive reagents should make this protocol a valuable alternative to the existing methods.
- Yin, Guodong,Gao, Meng,Wang, Zihua,Wu, Yandong,Wu, Anxin
-
body text
p. 369 - 372
(2009/04/07)
-
- Alkoxycarbonylation of aryl iodides using gaseous carbon monoxide and pre-pressurized reaction vessels in conjunction with microwave heating
-
The microwave-promoted alkoxycarbonylation of aryl iodides using reaction vessels pre-pressurized with carbon monoxide is reported. Reactions are performed using 0.1 mol% palladium acetate as catalyst, DBU as base and are complete within 20-30 min. A range of aryl iodide substrates can be converted to the corresponding esters using this methodology. Primary and secondary alcohols work well whereas a tertiary alcohol substrate proves less reactive. The potential for scale-up of the reaction has also been explored. The Royal Society of Chemistry.
- Kormos, Chad M.,Leadbeater, Nicholas E.
-
-
- Alkoxycarbonylation reactions performed using near-stoichiometric quantities of CO
-
Alkoxycarbonylation reactions using near-stoichiometric quantities of carbon monoxide gas are presented. The reactions are performed using microwave heating which, as well as the inherent advantages of rate acceleration, offers a convenient method for loading vessels with gases. Georg Thieme Verlag Stuttgart.
- Kormos, Chad M.,Leadbeater, Nicholas E.
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p. 2006 - 2010
(2008/02/09)
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- A fast and simple method for the acylation of alcohols with acid chlorides promoted by metallic samarium
-
Acylation of primary, secondary, allyl and benzyl alcohols with acid chlorides promoted by samarium metal under neutral condition gave carboxylic acid esters in good to excellent yields. Acylation of a tertiary alcohol did not occur under the same reaction conditions.
- Jia, Xue-Shun,Wang, Hai-Long,Huang, Qing,Kong, Ling-Long,Zhang, Wei-He
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p. 135 - 138
(2007/10/03)
-
- Scope and mechanistic insights into the use of tetradecyl(trihexyl) phosphonium bistriflimide: A remarkably selective ionic liquid solvent for substitution reactions
-
A survey of substitution reactions conducted in a phosphonium bistriflimide ionic liquid is presented. The results demonstrate high selectivity favoring substitution over typically competitive elimination and solvolytic processes even when challenging secondary and tertiary electrophiles are employed. The first reports of Kornblum substitution reactions in an ionic liquid are described that proceed with very high chemoselectivity in favor of nitro over nitroso products and elimi nation side products. The structure-reactivity study indicates that these reactions proceed through a narrow spectrum of pathways ranging from straight SN2 to a preassociation pathway along a saddle point that approaches the SN1 limit. The barrier to the formation of dissociated carbocations is attributed to the structural features of this ionic liquid that favor intervention of the associated nucleophile over dissociation, also preventing cross over to E1 processes. The lack of any basic entity in the phosphonium bistriflimide ionic liquid appears to prevent any potential base-mediated elimination reactions, which makes this a highly selective medium for use in general substitution reactions.
- McNulty, James,Nair, Jerald J.,Cheekoori, Sreedhar,Larichev, Vladimir,Capretta, Alfredo,Robertson
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p. 9314 - 9322
(2007/10/03)
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- Solvent polarity and organic reactivity in mixed solvents: Evidence using a reactive molecular probe to assess the role of preferential solvation in aqueous alcohols
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(Chemical Equation Presented) Product selectivities [S = ([ester product]/[acid product]) x ([water]/[alcohol solvent])] are reported for solvolyses of p-methoxybenzoyl chloride (2) in aqueous methanol, ethanol, 2,2,2-trifluoroethanol, n-propyl alcohol, isopropyl alcohol, and tert-butyl alcohol at 25, 35, and 45°C. S values are small and depend significantly on the alcohol cosolvent, varying from 1.3 in methanol to 0.1 in tert-butyl alcohol, but S depends only slightly on the solvent composition, and on the temperature. As S adjusts the product ratios for changes in bulk solvent compositions, it is suggested that preferential solvation by either alcohol or water at the reaction site is not a major factor influencing rates or products. Logarithms of rates of solvolyses of 2 correlate well with Kosower Z values (based on solvatochromism). In contrast, another solvatochromic polarity index, ET(30), shows "dispersion" in correlations with the solvent ionizing power parameter, YOTs, probably due to aromatic ring and other solvation effects.
- Bentley, T. William,Ebdon, David N.,Kim, Eun-Ju,In, Sun Koo
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p. 1647 - 1653
(2007/10/03)
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- A mild esterification process in phosphonium salt ionic liquid
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A general, high yielding procedure is described for the esterification of carboxylic acids through carboxylate alkylation in phosphonium salt ionic liquid.
- McNulty, James,Cheekoori, Sreedhar,Nair, Jerald J.,Larichev, Vladimir,Capretta, Alfredo,Robertson, Al J.
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p. 3641 - 3644
(2007/10/03)
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- 5,5-Dimethyl-1,4,2-dioxazoles as versatile aprotic hydroxamic acid protecting groups
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5,5-Dimethyl-1,4,2-dioxazoles are readily installed by transketalization of 2,2-diethoxypropane, where both the NH and OH moieties are protected in a nonprotic form. The dioxazoles are stable to a wide variety of reaction conditions and readily revert back to the hydroxamic acid by treatment with Nafion-H in 2-propanol. The method is applicable to primary, secondary, tertiary, and aromatic hydroxamic acids, and the acidity of the protons adjacent to the dioxazole allows α-functionalization.
- Couturier, Michel,Tucker, John L.,Proulx, Caroline,Boucher, Ghislain,Dube, Pascal,Andresen, Brian M.,Ghosh, Arun
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p. 4833 - 4838
(2007/10/03)
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- Direct conversion of acylsilanes to esters mediated by iron (III) and nitrate ions
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Acylsilanes, RC(O)SiMe3 (R = C6H5, p-MeOC6H4 and C5H11), can be converted into their corresponding carboxylic acids, when water is used as solvent, and esters when alcohol is used as solvent. This oxidation is mediated by iron (III) ions in 20-24 h or nitric acid diluted in alcohol in 2-10 h at room temperature.
- Patrocinio, Amauri F.,Moran, Paulo J. S.
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p. 1419 - 1423
(2007/10/03)
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- Oxidation of Benzaldehydes Catalyzed by Methyltrioxorhenium with Hydrogen Peroxide
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Methyltrioxorhenium-catalyzed oxidation of benzaldehydes with hydrogen peroxide gives corresponding phenols in good yield.Benzaldehydes substituted with methoxy or hydroxyl groups at 2- and/or 4-position are good substrates for this reaction.
- Yamazaki, Shigekazu
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p. 127 - 128
(2007/10/02)
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- NOVEL OXIDATIVE CLEAVAGE OF CARBON-CARBON BOND IN HYDRAZONES BY OXYGENATION WITH COBALT SCHIFF BASE COMPLEX
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Oxygenation of aromatic ketone hydrazones with Co(salen) in methanol resulted unexpectedly in oxidative degradation to give methyl benzoate derivatives.A mechanism involving nucleophilic attack by methanol on a diazo intermediate is discussed.
- Nishinaga, Akira,Yamazaki, Shigekazu,Matsuura, Teruo
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p. 2649 - 2652
(2007/10/02)
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- PALLADIUM(0) AND RHODIUM(I) CATALYSIS OF THE CARBONYLATION OF UNACTIVATED BROMIDES
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Alkyl, vinyl, and aromatic bromides react with organoborates and carbon monoxide, in the presence of catalytic quantities of 1,5-hexadienerhodium(I) chloride dimer and tetrakis(triphenylphosphine)palladium(0), to give carboxylic esters in good yields.
- Hashem, Khaled E.,Woell, James B.,Alper, Howard
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p. 4879 - 4880
(2007/10/02)
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