- Functional analysis of repositioned anilide derivatives as anticancer compounds
-
Off the different types cancers 40% of the population have been observed to be affected by leukemia. Contemporary therapeutics is focusing on generation of new synthetic analogues that can exert maximum positive physiological effect with minimum dosage and negligible deleterious side effects. New generation pharmacists are focusing on such promising effects of Imatinib (a potential anti-cancer drug molecule), Dasatinib, Pelitinib and Nilotinib. The present research study focuses on novel synthesized anilides derivative against BCR-ABL kinase as potential anti-leukemic agent. Validation of the compounds by molecular docking with specific BCR-ABL kinase confirmed their activity. Toxicity prediction of these compounds helped to identify sustainability as therapeutic molecules. The IC50 values were calculated (211 ug, 175 ug, 272ug for compounds A, B, C resp.) and the mode of cell death was gauged by DNA laddering assay. The cells were observed to be induced for programmed cell death. By validating and in-vivo testing of three synthesized compounds, the compound B was observed to be more stable thermodynamically with a potentially vital active site and appears to be a promising anti-leukemic factor. The present research thus lays a preliminary platform in world of pharmaceutics, where these new analogues appear to be efficient, target specific and less toxic molecules.
- Chhajed, Santosh S.,Dasgupta, Debjani,Gupta, Pramodkumar P.,Panesar, Ramanpreet Kaur,Parab, Mala,Pathan, Saliha S.
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- Energy-Transfer-Mediated Photocatalysis by a Bioinspired Organic Perylenephotosensitizer HiBRCP
-
Energy transfer plays a special role in photocatalysis by utilizing the potential energy of the excited state through indirect excitation, in which a photosensitizer determines the thermodynamic feasibility of the reaction. Bioinspired by the energy-transfer ability of natural product cercosporin, here we developed a green and highly efficient organic photosensitizer HiBRCP (hexaisobutyryl reduced cercosporin) through structural modification of cercosporin. After structural manipulation, its triplet energy was greatly improved, and then, it could markedly promote the efficient geometrical isomerization of alkenes from the E-isomer to the Z-isomer. Moreover, it was also effective for energy-transfer-mediated organometallic catalysis, which allowed realization of the cross-coupling of aryl bromides and carboxylic acids through efficient energy transfer from HiBRCP to nickel complexes. Thus, the study on the relationship between structural manipulation and their photophysical properties provided guidance for further modification of cercosporin, which could be applied to more meaningful and challenging energy-transfer reactions.
- Zhang, Yan,Xia, Mingze,Li, Min,Ping, Qian,Yuan, Zhenbo,Liu, Xuanzhong,Yin, Huimin,Huang, Shuping,Rao, Yijian
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p. 15284 - 15297
(2021/11/01)
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- Hydrogen-bond-assisted transition-metal-free catalytic transformation of amides to esters
-
The amide C-N cleavage has drawn a broad interest in synthetic chemistry, biological process and pharmaceutical industry. Transition-metal, luxury ligand or excess base were always vital to the transformation. Here, we developed a transition-metal-free hydrogen-bond-assisted esterification of amides with only catalytic amount of base. The proposed crucial role of hydrogen bonding for assisting esterification was supported by control experiments, density functional theory (DFT) calculations and kinetic studies. Besides broad substrate scopes and excellent functional groups tolerance, this base-catalyzed protocol complements the conventional transition-metal-catalyzed esterification of amides and provides a new pathway to catalytic cleavage of amide C-N bonds for organic synthesis and pharmaceutical industry. [Figure not available: see fulltext.]
- Huang, Changyu,Li, Jinpeng,Wang, Jiaquan,Zheng, Qingshu,Li, Zhenhua,Tu, Tao
-
-
- Copper-mediated simple and direct aerobic oxidative esterification of arylacetonitriles with alcohols/phenols
-
A simple and direct aerobic oxidative esterification reaction of arylacetonitriles with alcohols/phenols is achieved in the presence of a copper salt and molecular oxygen, which produces a broad range of aryl carboxylic acid esters in good to high yields. Copper salt plays multiple roles in the transformation, which allows the oxygenation of C-H bond, cleavage of inert C-C bond, and formation of C-O bond in one pot without the assistance of any of the acids, bases, ligands, and so on. The reaction provides a simple, direct, and efficient protocol towards functionalized esters, especially aryl benzoates, from readily available starting materials.
- Dong, Jianyu,Chen, Xiuling,Ji, Fangyan,Liu, Lixin,Su, Lebin,Mo, Min,Tang, Jian-Sheng,Zhou, Yongbo
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-
- Nickel-Mediated Trifluoromethylation of Phenol Derivatives by Aryl C?O Bond Activation
-
The increasing pharmaceutical importance of trifluoromethylarenes has stimulated the development of more efficient trifluoromethylation reactions. Tremendous efforts have focused on copper- and palladium-mediated/catalyzed trifluoromethylation of aryl halides. In contrast, no general method exists for the conversion of widely available inert electrophiles, such as phenol derivatives, into the corresponding trifluoromethylated arenes. Reported herein is a practical nickel-mediated trifluoromethylation of phenol derivatives with readily available trimethyl(trifluoromethyl)silane (TMSCF3). The strategy relies on PMe3-promoted oxidative addition and transmetalation, and CCl3CN-induced reductive elimination. The broad utility of this transformation has been demonstrated through the direct incorporation of trifluoromethyl into aromatic and heteroaromatic systems, including biorelevant compounds.
- Hu, Wei-Qiang,Pan, Shen,Qing, Feng-Ling,Vicic, David A.,Xu, Xiu-Hua
-
supporting information
p. 16076 - 16082
(2020/07/04)
-
- Supramolecular Pd(II) complex of DPPF and dithiolate: An efficient catalyst for amino and phenoxycarbonylation using Co2(CO)8 as sustainable C1 source
-
Highly active, efficient and robust “dppf ligated tetranuclear palladium dithiolate complex” was synthesized and applied as a catalyst for chemical fixation of carbon monoxide for the synthesis value added chemicals such as tertiary amide and aromatic esters. The synthesized catalyst was characterized using different analytical techniques such as elemental analysis, 1H and 31P NMR spectroscopy. The use of Co2(CO)8 as a cheap, less toxic and low melting solid surrogate are additional advantages over the current protocol. The catalyst showed superior activity towards the Amino (10?3 mol % catalyst) and Phenoxycarbonylation (10-2 mol % catalyst) and high TON (104 to 103) and TOF (103 to 102 h-1). The Betol and Lintrin (active drug molecules) were synthesized under an optimized reaction condition. The scalability of the current protocol has been demonstrated up-to the gram level.
- Gaikwad, Vinayak V.,Mane, Pravin A.,Dey, Sandip,Patel, Divya,Bhanage, Bhalchandra M.
-
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- Visible light-mediated transition metal-free esterification of amides with boronic acids
-
A novel strategy for visible light-mediated esterification of amides with boronic acids in air has been described. This method is characterized by mild reaction conditions and low cost owing to no need of any catalyst, which implies high potential utility in late-stage functionalization of amide drugs and materials.
- Ding, Hao,Qi, Wan-Ying,Zhen, Jing-Song,Ding, Qiuping,Luo, Yong
-
supporting information
(2020/10/02)
-
- Reductive C-O, C-N, and C-S Cleavage by a Zirconium Catalyzed Hydrometalation/β-Elimination Approach
-
A zirconium catalyzed reductive cleavage of Csp3 and Csp2 carbon-heteroatom bonds is reported that makes use of a tethered alkene functionality as a traceless directing group. The reaction is successfully demonstrated on C-O, C-N, and C-S bonds and proposed to proceed via a hydrozirconation/β-heteroatom elimination sequence of an in situ formed zirconium hydride catalyst. The positional isomerization of the catalyst further enables the cleavage of homoallylic ethers and the removal of terminal allyl and propargyl groups.
- Matt, Christof,K?lblin, Frederic,Streuff, Jan
-
supporting information
p. 6983 - 6988
(2019/09/09)
-
- Palladium-Catalyzed Aerobic Oxidative Coupling of Amides with Arylboronic Acids by Cooperative Catalysis
-
The first fluoride and palladium co-catalyzed conversion of amide to ester through an aerobic oxidative coupling pathway is reported. This new approach presents a practical process that employs easily available oxygen and commercially available arylboronic acids as coupling partners, uses a wide range of N- tosylamides, and proceeds under mild reaction conditions. This protocol demonstrates broad functional group tolerance, and provides an alternative option to synthesize esters from N-tosylamides which obtained by simply N-functionalization of secondary amides.
- Li, Yue,Wu, Hongxiang,Zeng, Zhuo
-
supporting information
p. 4357 - 4361
(2019/07/09)
-
- Enol Ester Intermediate Induced Metal-Free Oxidative Coupling of Carboxylic Acids and Arylboronic Acids
-
A facile, efficient and environmentally friendly methodology for the preparation of phenolic esters is realized via metal-free coupling of carboxylic acids and arylboronic acids. This sequential one pot reaction, employing methyl propiolate as an activating reagent, proceeds through the formation of enol ester intermediate, followed by a nucleophilic attack on the C-O bond under the oxidation of hydrogen peroxide. These studies display that enol esters, despite previously being overlooked as synthetic intermediates, would be the valuable building blocks for developing carbon–carbon and carbon–heteroatom bond-forming reactions.
- Xu, Xianjun,Feng, Huangdi,Li, Huiqiong,Huang, Liliang
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p. 3921 - 3928
(2019/06/24)
-
- Base-Promoted Amidation and Esterification of Imidazolium Salts via Acyl C-C bond Cleavage: Access to Aromatic Amides and Esters
-
Imidazolium salts have been effectively employed as suitable acyl transfer agents in amidation and esterification in organic synthesis. The weak acyl C(O)-C imidazolium bond was exploited to generate acyl electrophiles, which further react with amines and alcohols to afford amides and esters. The broad substrate scope of anilines and benzylic amines and base-promoted conditions are the benefits of this route. Interestingly, phenol, benzylic alcohols, and a biologically active alcohol can also be subjected to esterification under the optimized conditions.
- Karthik, Shanmugam,Muthuvel, Karthick,Gandhi, Thirumanavelan
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p. 738 - 751
(2019/01/24)
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- Preparation method for synthesis of phenolic ester through thiocarboxylic acid mediated visible light catalyzed phenol acylation reaction
-
The invention discloses a preparation method for synthesis of phenolic ester through a thiocarboxylic acid mediated visible light catalyzed phenol acylation reaction. Thiocarboxylic acid compounds andphenol compounds are subjected to a site specific reaction under certain conditions to produce phenolic ester compounds, wherein the certain conditions are as follows: under the conditions of normaltemperature, normal pressure and visible light, K2CO3 is used as an alkaline catalyst, terpyridyl ruthenium dichloride hexahydrate is used as a photosensitizer and acetonitrile is used as a reaction solvent. Synthesis of phenolic ester under catalysis of visible light is realized, thiocarboxylic acid is used as an acylation reagent, and the site specific phenol esterification reaction is realizedefficiently under mild conditions of normal temperature, normal pressure and visible light. The method has mild reaction conditions, large substrate functional group tolerance, high applicability andhigh yield, and an efficient, reliable and economical preparation method is provided for synthesis of phenolic ester.
- -
-
Paragraph 0079; 0080; 0127; 0128; 0129
(2018/07/30)
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- Acceptorless Dehydrogenation of Hydrocarbons by Noble-Metal-Free Hybrid Catalyst System
-
A hybrid catalysis that comprises an acridinium photoredox catalyst, a thiophosphate organocatalyst, and a nickel catalyst-enabled acceptorless dehydrogenation of hydrocarbons is reported. The cationic nickel complex played a critical role in the reactivity. This is the first example of acceptorless dehydrogenation of hydrocarbons by base metal catalysis under mild reaction conditions of visible light irradiation at room temperature.
- Fuse, Hiromu,Kojima, Masahiro,Mitsunuma, Harunobu,Kanai, Motomu
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p. 2042 - 2045
(2018/04/16)
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- Transesterification of (hetero)aryl esters with phenols by an Earth-abundant metal catalyst
-
Readily available and inexpensive Earth-abundant alkali metal species are used as efficient catalysts for the transesterification of aryl or heteroaryl esters with phenols which is a challenging and underdeveloped transformation. The simple conditions and the use of heterogeneous alkali metal catalyst make this protocol very environmentally friendly and practical. This reaction fills in the missing part in transesterification reaction of phenols and provides an efficient approach to aryl esters, which are widely used in the synthetic and pharmaceutical industry.
- Chen, Jianxia,Namila,Bai, Chaolumen,Baiyin, Menghe,Agula, Bao,Bao, Yong-Sheng
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p. 25168 - 25176
(2018/07/29)
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- Palladium Catalyzed Carbonylative Coupling for Synthesis of Arylketones and Arylesters Using Chloroform as the Carbon Monoxide Source
-
We describe a modular, palladium catalyzed synthesis of aryl(hetero)aryl benzophenones and aryl benzoates from aryl(hetero)aryl halides using CHCl3 as the carbonyl source in the presence of KOH. The reaction occurs in tandem through an initial carbonylation to generate an aroyl halide, which undergoes coupling with arylboronic acids, bornonates, and phenols. Direct carbonylative coupling of indoles at the third position has also been accomplished under slightly modified reaction conditions by in situ activation of the C-H bond. Notably, CHCl3 is a convenient and safe alternation of CO gas, provides milder reaction conditions with high functional group tolerance, and gives the products in moderate to good yields.
- Sharma, Poonam,Rohilla, Sandeep,Jain, Nidhi
-
p. 1105 - 1113
(2018/06/18)
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- Palladium-Catalyzed Oxidative Carbonylation of Aryl Hydrazines with CO and O2 at Atmospheric Pressure
-
Palladium-catalyzed aerobic oxidative aminocarbonylation and alkoxycarbonylation reactions with aryl hydrazines as coupling partners have been developed. The oxidative carbonylation of aryl hydrazines proceeded smoothly at atmospheric pressure CO, employi
- Tu, Yongliang,Yuan, Lin,Wang, Tao,Wang, Changliu,Ke, Jiamei,Zhao, Junfeng
-
p. 4970 - 4976
(2017/05/12)
-
- Sodium cyanide-promoted copper-catalysed aerobic oxidative synthesis of esters from aldehydes
-
A simple and efficient copper-catalysed procedure for oxidative esterification of aldehydes with alcohols and phenols mediated by sodium cyanide, using air as a clean oxidant, is described. A variety of aromatic aldehydes and structurally different alcohols and phenols reacted efficiently, and the product esters were obtained in good to excellent yields under normal atmospheric and solvent-free conditions.
- Nowrouzi, Najmeh,Abbasi, Mohammad,Bagheri, Maryam
-
-
- K2CO3-promoted formation of aryl esters from primary aryl amides by the acyl-acyl exchange process
-
A new acyl-acyl exchange reaction has been developed for the formation of aryl esters from primary aryl amides. The reaction could occur under mild reaction conditions with catalytic quantities of K2CO3, and could afford moderate to good yields of the desired products.
- Bian, Yongjun,Qu, Xingyu
-
supporting information
p. 3869 - 3872
(2016/05/24)
-
- Solid-Phase Benzoylation of Phenols and Alcohols in Microwave Reactor: An Ecofriendly Protocol
-
An efficient solid-phase benzoylation of phenols and alcohols was developed under microwave irradiation. A stoichiometric amount of benzoyl chloride was sufficient to carry out the reaction. This benzoylation features short reaction time, good yields, and easy workup procedures. Furthermore, the scope of the reaction was extended to prepare 3,5-dinitrobenzoyl derivatives of alcohols.
- Chakraborty, Suchandra,Saha, Ahana,Basu, Kaushik,Saha, Chandan
-
supporting information
p. 2331 - 2343
(2015/10/12)
-
- The first vinyl acetate mediated organocatalytic transesterification of phenols: A step towards sustainability
-
The present report outlines our efforts toward a simple yet elegant protocol for O-acylation of a wide variety of phenols. This highly enabling and solventless method relies on vinyl acetate as an innocuous acyl donor and DABCO as an organocatalyst. Operational simplicity, excellent yields, higher and faster conversion rates without excess reagents, a simple workup and essentially no need of columns are some of the salient features of the reported protocol.
- Kumar, Manoj,Bagchi, Sourav,Sharma, Anuj
-
p. 8329 - 8336
(2015/11/10)
-
- A novel nickel-catalyzed synthesis of thioesters, esters and amides from aryl iodides in the presence of chromium hexacarbonyl
-
This study describes our findings on a novel and cheap NiCl2 catalytic system under ligand-free conditions for the efficient thiocarbonylation, alkoxycarbonylation and amidocarbonylation reactions of aryl iodides in the presence of Cr(CO)6 as the solid source of carbon monoxide under air. A variety of aryl iodides tolerated the reaction conditions and structurally different thiols, alcohols and amines were used efficiently. The corresponding thioesters, esters and amides were obtained in good to excellent yield at atmospheric pressure under mild reaction conditions.
- Iranpoor, Nasser,Firouzabadi, Habib,Etemadi-Davan, Elham,Nematollahi, Arash,Firouzi, Hamid Reza
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p. 6445 - 6452
(2015/08/11)
-
- Ligand-free palladium-catalyzed aerobic oxidative coupling of carboxylic anhydrides with arylboronic acids
-
We report a new, effective and environmentally friendly protocol for selective aerobic oxidative coupling of arylboronic acids with carboxylic anhydrides in the presence of ligand-free palladium catalyst. The aryl benzoates are obtained in good to excellent yields.
- Yin, Weiyan,He, Haifeng,Zhang, Yani,Long, Tong
-
p. 2402 - 2406
(2014/10/15)
-
- Polystyrene-supported GaCl3: A new, highly efficient and recyclable heterogeneous Lewis acid catalyst for acetylation and benzoylation of alcohols and phenols
-
A new, simple and highly chemoselective method for both acetylation and benzoylation of alcohols and phenols with acetic anhydride in the presence of polystyrene-supported gallium trichloride (PS/GaCl3) as a highly active and reusable heterogeneous Lewis acid catalyst is presented. In this catalytic system, primary, secondary and tertiary alcohols as well as phenols were converted to the corresponding acetates and benzoates with high yields. The heterogenized catalyst is of high reusability and stability in the acetylation reactions and was recovered several times with negligible loss in its activity or a negligible catalyst leaching, and also there is no need for regeneration. Remarkably, a selective mono-acetylation of symmetrical diols can be achieved chemoselectively by employing the same catalyst.
- Rahmatpour, Ali
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p. 1048 - 1054
(2013/02/22)
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- Palladium-catalyzed aerobic oxidative coupling of acyl chlorides with arylboronic acids
-
The first example of a palladium-catalyzed aerobic oxidative coupling of acyl chlorides with arylboronic acids has been developed, leading to a wide range of aryl benzoates in good to excellent yields. This catalytic system shows broad functional group tolerance. Preliminary mechanistic experiments using deuterium labeling showed that the oxygen atom was derived from dioxygen. Copyright
- Chen, Jiuxi,Peng, Yong,Liu, Miaochang,Ding, Jinchang,Su, Weike,Wu, Huayue
-
supporting information
p. 2117 - 2122
(2012/11/07)
-
- Ruthenium/NHC-catalyzed tandem benzylic oxidation/oxidative esterification of benzylic alcohols with phenols
-
An efficient methodology to access benzoate derivatives via tandem benzylic oxidation/oxidative esterification of benzylic alcohols with phenols catalyzed by ruthenium/NHC was developed. This operationally simple one-pot process uses O2 as the clean oxidant, producing esters in good to excellent yields.
- Zhang, Di,Pan, Changduo
-
experimental part
p. 41 - 45
(2012/06/18)
-
- Palladium/NHC-catalyzed tandem benzylic oxidation/oxidative esterification of benzylic alcohols with phenols
-
A palladium/NHC-catalyzed tandem benzylic oxidation/oxidative esterification of benzylic alcohols with phenols to access aryl benzoate derivatives is described. The procedure tolerates a series of functional groups, such as methoxy, nitro, cyano, chloro, fluoro and bromo groups. Thus, it represents a practically alternative method to access aryl benzoate derivatives.
- Luo, Fang,Pan, Changduo,Cheng, Jiang,Chen, Fan
-
supporting information; experimental part
p. 5878 - 5882
(2011/09/12)
-
- Radical OfC transposition: A metal-free process for conversion of phenols into benzoates and benzamides
-
We report a metal-free procedure for transformation of phenols into esters and amides of benzoic acids via a new radical cascade. Diaryl thiocarbonates and thiocarbamates, available in a single high-yielding step from phenols, selectively add silyl radicals at the sulfur atom of the CdS moiety. This addition step, analogous to the first step of the Barton-McCombie reaction, produces a carbon radical which undergoes 1,2 OfC transposition through an O-neophyl rearrangement. The usually unfavorable equilibrium in the reversible rearrangement step is shifted forward via a highly exothermic C-S bond scission in the O-centered radical, which furnishes the final benzoic ester or benzamide product. The metal-free preparation of benzoic acid derivatives from phenols provides a potentially useful alternative to metal-catalyzed carbonylation of aryl triflates.
- Baroudi, Abdulkader,Alicea, Jeremiah,Flack, Phillip,Kirincich, Jason,Alabugin, Igor V.
-
p. 1521 - 1537
(2011/06/11)
-
- Palladium/NHC-catalyzed oxidative esterification of aldehydes with phenols
-
A palladium-catalyzed oxidative esterification of aldehydes with phenols is described, using air as the clean oxidant. This reaction tolerates many functional groups, providing esters with yields ranging from moderate to excellent.
- Zhang, Manli,Zhang, Shouhui,Zhang, Guoying,Chen, Fan,Cheng, Jiang
-
experimental part
p. 2480 - 2483
(2011/05/16)
-
- NHC/Iron cooperative catalysis: Aerobic oxidative esterification of aldehydes with phenols
-
An NHC/iron cooperative catalytic system mediates the aerobic oxidative esterification of aldehydes with phenols. The use of equimolar amounts of reactants led to good to excellent isolated yields of esters.
- Reddy, R. Sudarshan,Rosa, Joao N.,Veiros, Luis F.,Caddick, Stephen,Gois, Pedro M. P.
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supporting information; experimental part
p. 3126 - 3129
(2011/05/12)
-
- Transesterification catalyzed by iron(III) β-diketonate species
-
A practical and clean protocol for transesterification catalyzed by a 5 mol % cheap, non-toxic and moisture stable Fe(acac)3 or other iron(III) β-diketonate species in solvent, such as heptane under azeotropic condition is developed. A remarkable rate enhancement was observed upon the addition of 5 mol % of an inorganic base, such as Na2CO3, which suggests that faster formation of a dimeric μ-alkoxy-bridged iron(III) species under alkaline conditions facilitates catalytic turnover. This system provides smooth transesterification over a wide range of structurally diverse esters and alcohols without disturbing functional groups. In addition, the use of iron β-diketonate complexes as catalysts is more environmentally friendly, safer, and economical than other transition-metal catalysts. Preliminary mechanistic studies indicate that the active catalyst is likely a dimeric μ-alkoxy-bridged iron(III) species, as determined by X-ray crystallography of [Fe(dbm)2(O-n-Bu)]2 derived from the alcoholysis of Fe(dbm)3 under alkaline conditions.
- Weng, Shiue-Shien,Ke, Chih-Shueh,Chen, Fong-Kuang,Lyu, You-Fu,Lin, Guan-Ying
-
supporting information; experimental part
p. 1640 - 1648
(2011/04/17)
-
- NHC-iron-catalyzed aerobic oxidative aromatic esterification of aldehydes using boronic acids
-
(Figure presented) NHC-iron complexes prepared in situ very efficiently afforded benzoates via the aerobic oxidative aromatic esterification of aldehydes with boronic acids. This method uses equimolar amounts of both the aldehyde and the boronic acid allo
- Rosa, Joao N.,Reddy, R. Sudarshan,Candeias, Nuno R.,Cal, Pedro M. S. D.,Gois, Pedro M. P.
-
supporting information; experimental part
p. 2686 - 2689
(2010/09/03)
-
- A TFAA-H3PO4-mediated direct, metal-free and high-speed synthesis of aryl carboxylate esters from phenols
-
An operationally simple, mild and single-step method for the direct and metal-free synthesis of aryl carboxylate esters is described under a solvent free condition. The reaction of phenols including 2-naphthol (or 1-naphthol) with a variety of carboxylic acids in the presence of TFAA and 85% H3PO4 provided a range of aryl carboxylate esters in good yields within few minutes.
- Kankanala, Kavitha,Reddy, Vangala Ranga,Mukkanti, Khagga,Pal, Sarbani
-
experimental part
p. 505 - 508
(2009/12/26)
-
- TiO2: A simple and an efficient catalyst for esterification of phenols under solvent-free condition
-
In the presence of catalytic amount of titanium oxide (TiO2), without any additional solvent at 25°C, phenols are conveniently acylated by acid chlorides to get phenolic esters in excellent yields. The TiO2 powder can be reused three times after simple washing with CH2Cl 2.
- Pasha, Mohamed Afzal,Manjula, Krishnappa
-
p. 597 - 600
(2008/09/19)
-
- Ruthenium(III) acetylacetonate [Ru(acac)3] -An efficient recyclable catalyst for the acetylation of phenols, alcohols, and amines under neat conditions
-
A catalytic amount of ruthenium(III) acetylacetonate (2 mol%) [Ru(acac)3] enables solvent-free acetylation of phenols, alcohols, and amines at ambient temperature in good to excellent yields. Furthermore, the catalyst could be recovered and reused at least three times without a significant loss in yields.
- Varala, Ravi,Nasreen, Aayesha,Adapa, Srinivas R.
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p. 148 - 152
(2008/02/11)
-
- C-O-bond cleavage of esters with a naphthyl group in the higher triplet excited state during two-color two-laser flash photolysis
-
A C-O-bond cleavage of esters having a naphthyl group, NpCO-OR and RCO-ONp (Np = α- and βnaphthyl (αNp and βNp, respectively), R = Ph and Me), was found during the two-color two-laser flash photolysis in acetonitrile. The C-O-bond cleavage occurred when NpCO-OR and RCO-ONp were excited to the singlet excited states (S1). On the other hand, no reaction occurred from the lowest triplet excited states (T 1). When NpCO-OR(T1) and RCO-ONp(T1) were excited to the higher triplet excited states (Tn) using the second laser during the two-color two-laser flash photolysis, the C-O-bond cleavage occurred. The C-O-bond cleavage quantum yield (Φ) was estimated from the plots of the T1state esters disappeared within a laser flash versus the second laser intensities. The C-O-bond cleavage in βNpCO- OPh(Tn) occurred more efficiently than in αNpCO- OPh(Tn) and that in PhCO-OβNp(Tn) occurred more efficiently than in PhCO-OαNp(Tn). The Φ value for ester with Ph and β-Np groups was larger than that for ester with Ph and α-Np groups. The Φ value for MeCO-OαNp(T n) was similar to those for PhCO-ONp(Tn), while that for MeCO-OβNp(Tn) was much smaller than those for PhCO-ONp(T n) and MeCO-OαNp(Tn). On the other hand, no C-O-bond cleavage was observed in NpCO-OMe(Tn). The Φ value depended on the characters of the groups (Np, Ph, and Me) on the ester. Whether R is Ph or Me with or without π electron, respectively, is important for the C-O-bond cleavage. In other words, electronic delocalization of the T n state including Np and ester groups is necessary for the occurrence of the C-O-bond cleavage in NpCO-OR(Tn) and RCO-ONp(Tn).
- Cai, Xichen,Sakamoto, Masanori,Yamaji, Minoru,Fujitsuka, Mamoru,Majima, Tetsuro
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p. 3143 - 3149
(2008/02/05)
-
- Magnesium bistrifluoromethanesulfonimide as a new and efficient acylation catalyst
-
Magnesium bistrifluoromethanesulfonimide catalyzed the acetylation of phenols, alcohols, and thiols under solvent-free conditions at room temperature and in short times. Electron-deficient and sterically hindered phenols provided excellent yields. The catalyst was found to be general for acylation with other anhydrides, such as propionic, isobutyric, pivalic, chloroacetic, and benzoic anhydrides. The rate of acylation was influenced by the electronic and steric factors associated with the anhydride. The reaction with less electrophilic anhydrides (e.g., chloroacetic and benzoic anhydrides) required higher temperature (~80 °C). Chemoselective acetylation, pivalation, and benzoylation took place with acid-sensitive alcohols without any competitive dehydration/rearrangement.
- Chakraborti, Asit K.,Shivani
-
p. 5785 - 5788
(2007/10/03)
-
- Direct atom-efficient esterification between carboxylic acids and alcohols catalyzed by amphoteric, water-tolerant TiO(acac)2
-
A diverse array of oxometallic species were examined as catalysts for a test direct condensation of benzoic acid and 2-phenylethanol in 1:1 stoichiometry. Besides group IVB MOCl2-XH2O and TiOX 2-xH2O, group VB VOCl2-xTHF and group IVB TiO(acac)2 were found to be the most efficient and water-tolerant catalysts for the test reaction. The new neutral catalytic protocol with the optimal TiO(acac)2 tolerates many stereo/electronic structural variations in both (di)-acid (1°-3° alkyl and aryl) and (di)alcohol (1°, 2° alkyl, and aryl) components with high chemoselectivity.
- Chen, Chien-Tien,Munot, Yogesh S.
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p. 8625 - 8627
(2007/10/03)
-
- Facile catalyzed acylation of alcohols, phenols, amines and thiols based on ZrOCl2·8H2O and acetyl chloride in solution and in solvent-free conditions
-
Acylation of heteroatoms (O, N and S) with acetyl chloride based on the use of a catalytic amount of the moisture stable, inexpensive ZrOCl 2?8H2O, proceeds efficiently producing the corresponding acylated products in excellent yields.
- Ghosh, Rina,Maiti, Swarupananda,Chakraborty, Arijit
-
p. 147 - 151
(2007/10/03)
-
- Zinc oxide (ZnO) as a new, highly efficient, and reusable catalyst for acylation of alcohols, phenols and amines under solvent free conditions
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Zinc oxide (ZnO) is a highly efficient catalyst for the acylation of a variety of alcohols, phenols and amines with acid chlorides or acid anhydrides under solvent free conditions. Primary, secondary, tertiary, allylic and benzylic alcohols, diols and phenols with electron donating or withdrawing substituents can be easily acylated in good to excellent yield.
- Hosseini Sarvari, Mona,Sharghi, Hashem
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p. 10903 - 10907
(2007/10/03)
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- A green protocol for chemoselective O-acylation in the presence of zinc oxide as a heterogeneous, reusable and eco-friendly catalyst
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The solvent-free acylation of alcohols and phenols with acyl chlorides using ZnO as a catalyst is described. The remarkable selectivity under mild and neutral conditions, and recyclability of the catalyst, are advantages.
- Tamaddon, Fatemeh,Amrollahi, Mohammad Ali,Sharafat, Leily
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p. 7841 - 7844
(2007/10/03)
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- 'Green' methodology for efficient and selective benzoylation of nucleosides using benzoyl cyanide in an ionic liquid
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Benzoyl cyanide in the ionic liquid 1-methoxyethyl-3-methylimidazolium methanesulfonate has been employed as a 'green' alternative and mild reaction condition protocol to conventional pyridine-benzoyl chloride system for efficient and selective benzoylation of nucleosides (of both the ribo- and deoxyribo-series) at ambient temperatures. The use of benzoyl cyanide-ionic liquid combination has been successfully extended for highly efficient benzoylation of phenols, aromatic amines, benzyl alcohol, aliphatic diols, 3-aminophenol and 2-aminobenzylalcohol, which indicates the versatility of this benzoylating system.
- Prasad, Ashok K.,Kumar, Vineet,Malhotra, Shashwat,Ravikumar, Vasulinga T.,Sanghvi, Yogesh S.,Parmar, Virinder S.
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p. 4467 - 4472
(2007/10/03)
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- Nucleophilic acyl substitutions of anhydrides with protic nucleophiles catalyzed by amphoteric, oxomolybdenum species
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(Chemical Equation Presented) Among six different group VIb oxometallic species examined, dioxomolybdenum dichloride and oxomolybdenum tetrachloride were the most efficient catalysts to facilitate nucleophilic acyl substitution (NAS) of anhydrides with a myriad array of alcohols, amines, and thiols in high yields and high chemoselectivity. In contrast to the well-recognized redox chemical behaviors associated with oxomolybdenum(VI) species, the catalytic NAS was unprecedented and tolerates virtually all kinds of functional groups. By using benzoic anhydride as a mediator for in situ generation of an incipient mixed anhydride-MoO2Cl2 adduct with a given functional alkanoic acid, one can achieve oleate, dipeptide, diphenylmethyl, N-Fmoc-α-amino, pyruvic, and tert-butylthio ester, N-tert-butylamide, and trityl methacrylate syntheses with appropriate protic nucleophiles. The amphoteric character of the Mo=O unit in oxomolybdenum chlorides was found to be responsible for the catalytic NAS profile as supported by a control NAS reaction of using an authentic adduct-MoOCl2(O2-CBu t)2 between pivalic anhydride and MoO2Cl 2 as the catalyst.
- Chen, Chien-Tien,Kuo, Jen-Huang,Pawar, Vijay D.,Munot, Yogesh S.,Weng, Shieu-Shien,Ku, Cheng-Hsiu,Liu, Cheng-Yuan
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p. 1188 - 1197
(2007/10/03)
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- Facile catalyzed acylation of heteroatoms using BiCl3 generated in situ from the procatalyst BiOCl and acetyl chloride
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Acylation of a variety of alcohols, phenols, aliphatic and aromatic amines, a thiol and a thiophenol proceeds efficiently using BiCl3 generated in situ from the procatalyst BiOCl and acetyl chloride in a solvent or under solventless conditions, furnishing the corresponding acylated derivatives in very good to excellent yields.
- Ghosh, Rina,Maiti, Swarupananda,Chakraborty, Arijit
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p. 6775 - 6778
(2007/10/03)
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- 3,6-Dibenzoxyl-1,2-pyridazine: A new versatile benzoyl transferring agent for NH2, -OH and -SH benzoylations
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A newly synthesized 3,6-dibenzoxyl-1,2-pyridazine 3 has been investigated for its potential to transfer the benzoyl group to various organic substrates carrying -NH2, -OH and -SH groups. The benzoyl transfer is fairly general in scope, occurs under convenient conditions and provides good to excellent yields of benzoylated products. Moreover, by choosing proper conditions, it is possible to achieve chemoselective benzoylation in bi-functional molecules. For instance, N-benzoylation of aromatic amines can be selectively accomplished over that of aliphatic amines and vice versa by manipulating reaction conditions. Selective N- or O-benzoylation in aminophenols is also possible. Although, not studied in detail, we final that dibenzoate 3 can also be used to effect C-benzoylation of reactive phenols and ketones, as exemplified by the C-benzoylation of resorcinol and acetophenone, respectively. Dibenzoate 3, besides being a crystalline, easy to handle, solid possesses twice the potential as an acyl carrier compared to the other known acyl carriers. These features make 3 as an attractive choice for many applications pertaining to benzoyl transfer reactions.
- Mashraqui, Sabir Hussain,Shivaji, Jadhav Latika
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p. 927 - 935
(2007/10/03)
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- Copper(II) Tetrafluoroborate-Catalyzed Acetylation of Phenols, Thiols, Alcohols, and Amines
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Copper(II) tetrafluoroborate efficiently catalyzes acetylation of structurally diverse phenols, alcohols, thiols, and amines with stoichiometric amounts of Ac2O under solvent-free conditions at room temperature. Acid-sensitive alcohols are smoothly acetylated without competitive side reactions. The reaction is influenced by the steric and electronic factors associated with the substrate as well as the anhydride. Acetylation of a sterically hindered substrate requires excess of anhydride and longer time. Acylation with less electrophilic anhydrides affords poor to moderate yields.
- Chakraborti, Asit K.,Gulhane, Rajesh,Shivani
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p. 111 - 115
(2007/10/03)
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- Acyl maleic hydrazides as versatile acyl transferring agents
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Acyl maleic hydrazides have been found to act as effective acyl transferring agents to substrates containing heteroatom nucleophiles such as amines, phenols, alcohols and thiols under mild and convenient conditions.
- Mashraqui, Sabir H.,Shivaji, Jadhav L.
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p. 121 - 123
(2007/10/03)
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- Indium(III) chloride as a new, highly efficient, and versatile catalyst for acylation of phenols, thiols, alcohols, and amines
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Indium(III) chloride efficiently catalyses the acylation of structurally diverse phenols, alcohols, thiols, and amines under solvent free conditions. Acid sensitive alcohols are smoothly acylated without competitive side reactions. Acylation of 2-hydroxynaphthalene is carried out with carboxylic acids adopting the mixed anhydride protocol using trifluoroacetic anhydride.
- Chakraborti, Asit K.,Gulhane, Rajesh
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p. 6749 - 6753
(2007/10/03)
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- Isolation of an inclusion complex of naphthol and its benzoate as an intermediate in the solvent-free benzoylation reaction of naphthol
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A study was performed on isolation of an inclusion complex of naphthol and its benzoate as an intermediate in the solvent-free benzoylation reaction of naphthol. Solvent-free benzoylation reactions were carried out by heating a stirred mixture of phenols or naphthols and benzoyl chloride. The structure of the 2 : 1 inclusion complex of 2,3 naphthalenediol and its p-methylbenzoate was studied by X-ray analysis.
- Nakamatsu, Seiken,Yoshizawa, Kazuhiro,Toyota, Sinji,Toda, Fumio,Matijasic, Ivanka
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p. 2231 - 2234
(2007/10/03)
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- PhCOCI-Py/basic alumina as a versatile reagent for benzoylation in solvent-free conditions
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A solvent-free procedure using PhCOCl-Py/basic alumina under microwave irradiation has been developed for N-, O- and S-benzoylation.
- Paul, Satya,Nanda, Puja,Gupta, Rajive
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p. 374 - 380
(2007/10/03)
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- Synthesis and evaluation of esters and carbamates to identify critical functional groups for esterase-specific metabolism
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In an effort to develop novel prodrugs for viral directed enzyme prodrug therapy (VDEPT) approaches to chemotherapy, eleven esters and carbamates of o-nitrophenol, p-nitrophenol, and β-naphthol were synthesized and characterized as substrates for rabbit (rCE) and human liver (hCE1) carboxylesterases. All of the esters of o-, p-nitrophenols, and β-naphthols showed moderate hydrolysis by both rCE and hCE1. Esters of β-naphthols exhibited higher hydrolysis rates compared to esters of p-nitrophenols by rCE. Of the carbamates, 4-benzyl-piperazine-1-carboxylic acid 2-nitrophenol showed preferential hydrolysis by rCE compared to hCE1 with a Vmax of 54.4 μmoles/min/mg, and a Km value of 1071 μM. Substrate metabolism by a specific CE or inhibition of CEs by each compound depended on several factors, including the types of functional groups and linking moieties.
- Yoon, Kyoung Jin P.,Morton, Christopher L.,Potter, Philip M.,Danks, Mary K.,Lee, Richard E.
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p. 3237 - 3244
(2007/10/03)
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