- Alkoxycarbonylation reactions performed using near-stoichiometric quantities of CO
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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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Read Online
- Alkoxycarbonylation of aryl iodides using gaseous carbon monoxide and pre-pressurized reaction vessels in conjunction with microwave heating
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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.
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Read Online
- Application of a batch microwave unit for scale-up of alkoxycarbonylation reactions using a near-stoichiometric loading of carbon monoxide
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The ethoxycarbonylation of iodobenzene was performed on the 1 mol scale in batch mode using microwave heating. The reaction was performed using both an excess and a near stoichiometric loading of carbon monoxide, comparable yields being obtained. Six different alkoxycarbonylation reactions were then performed simultaneously on the 50 mmol scale using a near-stoichiometric loading of carbon monoxide with excellent conversions in each case.
- Iannelli, Mauro,Bergamelli, Fabio,Kormos, Chad M.,Paravisi, Stefano,Leadbeater, Nicholas E.
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Read Online
- Stepwise benzylic oxygenation via uranyl-photocatalysis
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Stepwise oxygenation at the benzylic position (1°, 2°, 3°) of aromatic molecules was comprehensively established under ambient conditions via uranyl photocatalysis to produce carboxylic acids, ketones, and alcohols, respectively. The accuracy of the stepwise oxygenation was ensured by the tunability of catalytic activity in uranyl photocatalysis, which was adjusted by solvents and additives demonstrated through Stern–Volmer analysis. Hydrogen atom transfer between the benzylic position and the uranyl catalyst facilitated oxygenation, further confirmed by kinetic studies. Considerably improved efficiency of flow operation demonstrated the potential for industrial synthetic application.
- Hu, Deqing,Jiang, Xuefeng
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supporting information
p. 124 - 129
(2022/01/19)
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- Photoinduced Acetylation of Anilines under Aqueous and Catalyst-Free Conditions
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A green and efficient visible-light induced functionalization of anilines under mild conditions has been reported. Utilizing nontoxic, cost-effective, and water-soluble diacetyl as photosensitizer and acetylating reagent, and water as the solvent, a variety of anilines were converted into the corresponding aryl ketones, iodides, and bromides. With advantages of environmentally friendly conditions, simple operation, broad substrate scope, and functional group tolerance, this reaction represents a valuable method in organic synthesis.
- Yang, Yu-Ming,Yan, Wei,Hu, Han-Wei,Luo, Yimin,Tang, Zhen-Yu,Luo, Zhuangzhu
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p. 12344 - 12353
(2021/09/02)
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- Oxidative Cleavage of Alkenes by O2with a Non-Heme Manganese Catalyst
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The oxidative cleavage of C═C double bonds with molecular oxygen to produce carbonyl compounds is an important transformation in chemical and pharmaceutical synthesis. In nature, enzymes containing the first-row transition metals, particularly heme and non-heme iron-dependent enzymes, readily activate O2 and oxidatively cleave C═C bonds with exquisite precision under ambient conditions. The reaction remains challenging for synthetic chemists, however. There are only a small number of known synthetic metal catalysts that allow for the oxidative cleavage of alkenes at an atmospheric pressure of O2, with very few known to catalyze the cleavage of nonactivated alkenes. In this work, we describe a light-driven, Mn-catalyzed protocol for the selective oxidation of alkenes to carbonyls under 1 atm of O2. For the first time, aromatic as well as various nonactivated aliphatic alkenes could be oxidized to afford ketones and aldehydes under clean, mild conditions with a first row, biorelevant metal catalyst. Moreover, the protocol shows a very good functional group tolerance. Mechanistic investigation suggests that Mn-oxo species, including an asymmetric, mixed-valent bis(μ-oxo)-Mn(III,IV) complex, are involved in the oxidation, and the solvent methanol participates in O2 activation that leads to the formation of the oxo species.
- Bennett, Elliot L.,Brookfield, Adam,Guan, Renpeng,Huang, Zhiliang,Mcinnes, Eric J. L.,Robertson, Craig M.,Shanmugam, Muralidharan,Xiao, Jianliang
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supporting information
p. 10005 - 10013
(2021/07/19)
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- Discovery of 1-Amino-1 H-imidazole-5-carboxamide Derivatives as Highly Selective, Covalent Bruton's Tyrosine Kinase (BTK) Inhibitors
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Bruton's tyrosine kinase (BTK) inhibitors suppressing the aberrant activation of BTK have led to a paradigm shift in the therapy of B-cell malignancies. However, there is an urgent need to discover more selective covalent BTK inhibitors owing to the off-t
- Ding, Qingjie,Fan, Goujie,Gao, Dingding,Jiang, Yuqin,Li, Qingyun,Li, Wei,Ma, Chunhua,Mao, Longfei,Xu, Guiqing,Yang, Shouning,Zhang, Dandan,Zhang, Shuting,Zhao, Jie,Zhao, Minghao,Zhu, Liang
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p. 16242 - 16270
(2021/11/12)
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- Highly selective electroreductive linear dimerization of electron-deficient vinylarenes
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A direct electroreductive dimerization of electron-deficient vinylarenes for the synthesis of 1,4-diarylbutane has been developed using a simple undivided cell with inexpensive carbon electrodes at room temperature. The control and deuterium-labeling experiments of electroreductive dimerization suggest that the hydrogen source comes from the solvent CH3CN. This protocol provides a mild and efficient route for the construction of C–C bond in moderate to good yields with high regioselectivity and broad substrate scope.
- Ning, Shulin,Zheng, Lianyou,Bai, Ya,Wang, Shutao,Wang, Siyu,Shi, Lingling,Gao, Qiansong,Che, Xin,Zhang, Zhuoqi,Xiang, Jinbao
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supporting information
(2021/11/16)
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- Metal- And additive-free C-H oxygenation of alkylarenes by visible-light photoredox catalysis
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A metal- and additive-free methodology for the highly selective, photocatalyzed C-H oxygenation of alkylarenes under air to the corresponding carbonyls is presented. The process is catalyzed by an imide-acridinium that forms an extremely strong photooxidant upon visible light irradiation, which is able to activate inert alkylarenes such as toluene. Hence, this is an easy to perform, sustainable and environmentally friendly oxidation that provides valuable carbonyls from abundant, readily available compounds.
- García Manche?o, Olga,Kuhlmann, Jan H.,Pérez-Aguilar, María Carmen,Piekarski, Dariusz G.,Uygur, Mustafa
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supporting information
p. 3392 - 3399
(2021/05/21)
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- SUBSTITUTED 1-AMINO-1H-IMIDAZOLE-5-CARBOXAMIDE AS BRUTON'S TYROSINE KINASE INHIBITORS
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Disclosed is a compound of formula I or a pharmaceutically acceptable salt, active metabolite, tautomer, stereoisomer, or prodrug thereof as BTK (Bruton's Tyrosine Kinase) inhibitors, which is useful for the treatment of autoimmune disease, inflammatory d
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Page/Page column 24-26
(2020/12/01)
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- Carbonylative Suzuki coupling and alkoxycarbonylation of aryl halides using palladium supported on phosphorus-doped porous organic polymer as an active and robust catalyst
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Developing highly active catalysts with the combined advantages of molecular and solid catalysis is considered as the “Holy Grail” in the area of catalysis research. Herein, a phosphorus-doped porous polymer-immobilized palladium was successfully developed as an efficient, robust, and recyclable catalyst for the carbonylative Suzuki coupling and alkoxycarbonylation reactions of aryl halides. Rather than just as an immobilizing molecular catalyst, palladium supported on phosphorus-doped porous organic polymer exhibits even better catalytic performances than that of its analogue homogeneous catalysts in both carbonylation reactions. Moreover, the catalyst can be easily separated and reused for at least 5 times without significant loss in reactivity. Importantly, the catalyst was highly stable under carbonylation reaction conditions, and no palladium nanoparticle was observed even after the 5th reuse.
- Wan, Yali,Song, Fangxiang,Ye, Tao,Li, Guangxing,Liu, Dingfu,Lei, Yizhu
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- A novel series of 4-methyl substituted pyrazole derivatives as potent glucagon receptor antagonists: Design, synthesis and evaluation of biological activities
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A novel series of 4-methyl substituted pyrazole derivatives were designed, synthesized and biologically evaluated as potent glucagon receptor (GCGR) antagonists. In this study, compounds 9q, 9r, 19d and 19e showed high GCGR binding (IC50 = 0.09 μM, 0.06 μM, 0.07 μM and 0.08 μM, respectively) and cyclic-adenosine monophosphate (cAMP) activities (IC50 = 0.22 μM, 0.26 μM, 0.44 μM and 0.46 μM, respectively) in cell-based assays. Most importantly, the docking experiment demonstrated that compound 9r formed extensive hydrophobic interactions with the receptor binding pocket, making it justifiable to further investigate the potential of becoming a GCGR antagonist.
- Shu, Shuangjie,Dai, Antao,Wang, Jiang,Wang, Bin,Feng, Yang,Li, Jia,Cai, Xiaoqing,Yang, Dehua,Ma, Dakota,Wang, Ming-Wei,Liu, Hong
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p. 1896 - 1908
(2018/03/12)
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- Towards a sustainable synthesis of amides: chemoselective palladium-catalysed aminocarbonylation of aryl iodides in deep eutectic solvents
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A palladium-catalysed aminocarbonylation of (hetero)aryl iodides has, for the first time, been accomplished in deep eutectic solvents as environmentally benign and recyclable media, under mild conditions. The reactions proceeded with a good substrate scope, and a variety of amides have been synthesized in yields up to 98%.
- Messa, Francesco,Perrone, Serena,Capua, Martina,Tolomeo, Francesco,Troisi, Luigino,Capriati, Vito,Salomone, Antonio
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p. 8100 - 8103
(2018/07/29)
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- Graphene Oxide: An Efficient Acid Catalyst for the Construction of Esters from Acids and Alcohols
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Graphene oxide was found to be an efficient and reusable acid catalyst for the esterification reaction. A wide range of aliphatic and aromatic acids and alcohols were compatible with the standard conditions and afforded the corresponding products in good yields. The heterogeneous catalyst can be easily recovered and recycled in dichloro-ethane solvent with good catalytic activity.
- Chen, Zhengwang,Wen, Yuelu,Fu, Yejuan,Chen, Hai,Ye, Min,Luo, Guotian
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supporting information
p. 981 - 985
(2017/05/05)
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- Design, synthesis, structure-activity relationships, and docking studies of pyrazole-containing derivatives as a novel series of potent glucagon receptor antagonists
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Glucagon receptor antagonists possess a great potential for treatment of type 2 diabetes mellitus. A series of pyrazole-containing derivatives were designed, synthesized and evaluated by biological assays as glucagon receptor antagonists. Most of the compounds exhibited good in vitro efficacy. Two of them, compounds 17f and 17k, displayed relatively potent antagonist effects on glucagon receptors with IC50 values of 3.9 and 3.6 μM, respectively. The possible binding modes of 17f and 17k with the cognate receptor were explored by molecular docking simulation.
- Shu, Shuangjie,Cai, Xiaoqing,Li, Jia,Feng, Yang,Dai, Antao,Wang, Jiang,Yang, Dehua,Wang, Ming-Wei,Liu, Hong
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p. 2852 - 2863
(2016/06/08)
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- Design, synthesis, pharmacological evaluation and molecular docking studies of substituted oxadiazolyl-2-oxoindolinylidene propane hydrazide derivatives
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The manuscript describes design and synthesis of novel oxadiazolyl-2-oxoindolinylidene propane hydrazides as amide tethered hybrids of indole and oxadiazole and their evaluation for antiinflammatory and analgesic activity. The compounds were synthesized following five step reaction to yield fifteen derivatives as 3-(5-substituted-1,3,4-oxadiazol-2-yl)-N′-[2-oxo-1,2-dihydro-3Hindol-3-ylidene]propane hydrazides. The final derivatives 3-[5-(4-hydroxyphenyl)-1,3,4-oxadiazol-2-yl]-N′-[2-oxo-1,2-dihydro-3H-indol-3-ylidene]propane hydrazide and 3-[5-(4-methylphenyl)-1,3,4-oxadiazol-2-yl]-N′-[2-oxo-1,2-dihydro-3H-indol-3-ylidene]propane hydrazide were found to be highly promising molecules with severity index of 0.35 and 0.56, respectively, which is promising for an analgesic compound. The hydroxy and methyl substitution on phenyl ring system provided with active anti-inflammatory compounds having increase in reaction time of 84.11 and 83.17percent, respectively compared to standard drug at 85.84percent. Molecular docking studies exhibit comparable interaction with synthesized derivatives and standard drug having a dock score of -4.44 by the K-nearest neighbour genetic algorithm method.
- Kerzare, Deweshri,Chikhale, Rupesh,Bansode, Ratnadeep,Amnerkar, Nikhil,Karodia, Nazira,Paradkar, Anant,Khedekar, Pramod
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p. 1998 - 2010
(2016/11/03)
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- Exploring the Catalytic Reactivity of Nickel Phosphine-Phosphite Complexes
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In this study, we present an investigation into various nickel phosphite and phosphite-phosphine complexes for use in the Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions and the ammonia arylation reaction. In these coupling reactions, it was discovered that the Ni[P(OEt)3]4, (dppf)Ni[P(OPh)3]2, and (binap)Ni[P(OPh)3]2 catalysts were the most effective. In addition, an optimisation process for these catalytic systems as well as functional group compatibility are discussed.
- Kampmann, Sven S.,Man, Nikki Y. T.,McKinley, Allan J.,Koutsantonis, George A.,Stewart, Scott G.
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p. 1842 - 1853
(2015/12/26)
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- Silica supported palladium-phosphine as a reusable catalyst for alkoxycarbonylation and aminocarbonylation of aryl and heteroaryl iodides
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Silica-supported palladium phosphine complexes were prepared for alkoxycarbonylation and aminocarbonylation of aryl iodides. These catalysts were highly efficient for the carbonylation of unprotected hydroxy-aryl, amino-aryl, iodoindole and iodopyrazole. The carbonylation of unprotected iodopyrazole is challenging and their carbonylation was achieved for the first and obtained corresponding carbonylative products are biologically active. The applicability of developed protocols tolerates wide range of functional groups with excellent yields. The catalyst was easily recovered and shows significant recyclability up to five consecutive cycles without loss in its catalytic activity and selectivity. The prepared catalysts were characterized by different techniques such as FEG-SEM, EDS, FT-IR, XPS and ICP-AES spectroscopy.
- Mane, Rajendra Shivaji,Sasaki, Takehiko,Bhanage, Bhalchandra Mahadeo
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p. 94776 - 94785
(2015/11/24)
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- Palladium supported on triphenylphosphine functionalized porous organic polymer: A highly active and recyclable catalyst for alkoxycarbonylation of aryl iodides
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An efficient method for the alkoxycarbonylation of aryl iodides using palladium supported on triphenylphosphine functionalized porous organic polymer (Pd@KAPs(Ph-PPh3)) as the catalyst is reported. Under balloon pressure of CO, various aryl iodides on carbonylation with alcohols and phenols give the corresponding products in moderate to excellent yields (74-96%). The catalyst can be easily separated by simple filtration process and recycled up to ten times without significant decrease in activity. The salient features of this protocol are the simplicity in handling of the catalyst, low CO pressure, negligible palladium leaching and good catalyst recyclability.
- Lei, Yizhu,Wu, Linjuan,Zhang, Xuefeng,Mei, Hui,Gu, Yanlong,Li, Guangxing
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p. 164 - 169
(2015/02/19)
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- Expedient carbonylation of aryl halides in aqueous or neat condition
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An expedient and versatile, microwave-assisted procedure for the carbonylation of aryl halides with boronic acids, alcohols or amines in water or under neat conditions has been developed. The reaction is catalyzed by fluorous, oxime-based palladacycle 1 that shows an excellent recyclable property and low levels of Pd leaching. To demonstrate the usefulness of the protocol, we applied it to the preparation of compounds of pharmaceutical interest, including a precursor of the reverse transcriptase inhibitor, niacin, benzocaine and butamben.
- Ang, Wei Jie,Lo, Lee-Chiang,Lam, Yulin
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p. 8545 - 8558
(2014/12/11)
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- Polymer supported Pd catalyzed carbonylation of aryl bromides for the synthesis of aryl esters and amides
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A polymer-anchored palladium(ii) catalyst was synthesized and characterized using various spectroscopic techniques. Its catalytic activity was evaluated for the alkoxycarbonylation and aminocarbonylation reactions. These carbonylation reactions were carried out for various substituted aryl bromides using alcohols and amines. Both the reactions were optimized by varying the bases, temperature and solvents. These experiments were carried out under high CO pressure. The catalyst was very stable and can be facilely recovered and reused six times without a significant decrease in its activity and selectivity. the Partner Organisations 2014.
- Islam, Sk Manirul,Ghosh, Kajari,Roy, Anupam Singha,Molla, Rostam Ali
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p. 38986 - 38999
(2014/11/07)
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- Identification of pirinixic acid derivatives bearing a 2-aminothiazole moiety combines dual PPARα/γ activation and dual 5-LO/mPGES-1 inhibition
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The concept of dual PPARα/γ activation was originally proposed as a new approach for the treatment of the metabolic syndrome. However, recent results indicated that PPARα as well as PPARγ activation might also be beneficial in the treatment of inflammator
- Hanke, Thomas,Lamers, Christina,Gomez, Roberto Carrasco,Schneider, Gisbert,Werz, Oliver,Schubert-Zsilavecz, Manfred
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supporting information
p. 3757 - 3763
(2014/09/17)
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- Immobilized palladium metal-containing ionic liquid-catalyzed alkoxycarbonylation, phenoxycarbonylation, and aminocarbonylation reactions
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Immobilized palladium metal-containing ionic liquid (ImmPd-IL), a structurally well-defined transition metal complex, is explored as an immobilized, phosphine-free catalyst for carbonylation reactions, including alkoxycarbonylation, phenoxycarbonylation, and aminocarbonylation reactions. The effect of various reaction parameters, such as solvent, base, time, temperature, and CO pressure on carbonylation reactions using ImmPd-IL catalyst was investigated. The optimized protocol was applied to a wide variety of substituted aryl iodides and various alcohol/phenols and amines having different steric and electronic properties and afforded the corresponding products in good to excellent yield. The developed catalytic system circumvents the use of phosphine ligands, with an additional advantage of palladium catalyst recovery and reuse for up to four consecutive cycles. The recycled catalyst was characterized using XPS analysis.
- Khedkar, Mayur V.,Sasaki, Takehiko,Bhanage, Bhalchandra M.
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p. 287 - 293
(2013/08/25)
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- An unusual 1,2-aryl shift in palladium-catalyzed cross-coupling ethoxycarbonylation of arylboronic acids with α-iminoesters
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The Pd-catalyzed cross-coupling ethoxycarbonylation of aryl boronic acids with N-aryl-α-iminoesters affords aryl carboxylic esters via carbonyl-imino σ bond cleavage. This unprecedented mode of reaction allows regioselective installation of the ethoxycarbonyl group into target molecules. Mechanism studies have revealed that an unusual 1,2-aryl shift process is involved in the transformation. The Royal Society of Chemistry.
- Qian, Cheng,Chen, Jiayan,Fu, Meiqin,Zhu, Shiya,Chen, Wen-Hua,Jiang, Huanfeng,Zeng, Wei
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p. 6013 - 6022
(2013/09/12)
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- Mild and efficient nickel-catalyzed heck reactions with electron-rich olefins
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A new efficient protocol for the nickel-catalyzed Heck reaction of aryl triflates with vinyl ethers is presented. Mild reaction conditions that equal those of the corresponding palladium-catalyzed Heck reaction are applied, representing a practical and more sustainable alternative to the conventional regioselective arylation of vinyl ethers. A catalytic system comprised of Ni(COD)2 and 1,1″-bis(diphenylphosphino)ferrocene (DPPF) in combination with the tertiary amine Cy2NMe proved effective in the olefination of a wide range of aryl triflates. Both electron-deficient and electron-rich arenes proved compatible, and the corresponding aryl methyl ketone could be secured after hydrolysis in yields approaching quantitative. Good functional group tolerance was observed matching the characteristics of the analogous Pd-catalyzed Heck reaction. The high levels of catalytic activity were explained by the intermediacy of a cationic nickel(II) complex potentially responsible for the successive β-hydride elimination and base promoted catalyst regeneration. Although these elementary reactions are normally considered challenging, DFT calculations suggested this pathway to be favorable under the applied reaction conditions.
- Gogsig, Thomas M.,Kleimark, Jonatan,Nilsson Lill, Sten O.,Korsager, Signe,Lindhardt, Anders T.,Norrby, Per-Ola,Skrydstrup, Troels
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supporting information; experimental part
p. 443 - 452
(2012/03/07)
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- Simple and facile benzylic C-H oxidation using (diacetoxyiodo)benzene and catalytic sodium azide
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A synthetic utility of hypervalent iodine reagent, (diacetoxyiodo)benzene, with a catalytic amount of sodium azide for oxidation of benzylic C-H to corresponding ketone compounds is described. The advantage of this protocol is characterized by mild reaction conditions and shorter reaction time to obtain moderate to good yields. Copyright Taylor & Francis Group, LLC.
- Telvekar, Vikas N.,Sasane, Kulbhushan A.
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scheme or table
p. 1325 - 1329
(2012/04/04)
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- A continuous-flow approach to palladium-catalyzed alkoxycarbonylation reactions
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Using a continuous-flow approach, it is possible to perform alkoxycarbonylation reactions of aryl iodides. Optimized reactor design allows for adequate mixing of gaseous and liquid reagents. Reactions are performed at rates of around 3 mL/min and at concentrations of 1 M, allowing for significant volumes to be processed per unit time. Palladium acetate (0.5 mol %) is used as the catalyst without the need for an additional ligand.
- Kelly, Christopher B.,Lee, Christopher,Mercadante, Michael A.,Leadbeater, Nicholas E.
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experimental part
p. 717 - 720
(2011/12/01)
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- Carbonylation of aryl halides: Extending the scope of the reaction
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Carbonylation reactions are being increasingly favoured in pharmaceutical chemistry for the atom-efficient introduction of carbonyl centres in aldehydes, acids, esters, and amides. Convenient procedures for simple aryl iodides and bromides are well established, and now the need is to develop improved conditions to allow the reactions to be extended to the more unreactive substrates, such as sterically hindered compounds and aryl chlorides. Sterically hindered compounds such as 2-iodo- or 2-bromo-m-xylenes can be converted using alkoxy and aminocarbonylation, while dehalogenation becomes a significant side reaction for reductive carbonylation. Less hindered compounds such as 2-iodo- or bromotoluene can be reacted successfully. Changing the aryl ligands of PdCl2{Ph2P(CH2)3PPh2} to alkyl groups improves the rate of oxidative addition but slows the carbonyl insertion step such that rates for the majority of aryl bromides are not improved by this change. Complexes such as PdCl2{Cy 2P(CH2)3PCy2} offer better performance for alkoxy and aminocarbonylation of aryl chlorides. However, for reductive carbonylation dehalogenation is a significant side reaction. Increasing CO pressure results in additional CO coordination to the catalytic intermediates and slows the reaction, while the dehalogenation is little affected, so reaction selectivity suffers. Thus, CO pressure is a critical parameter, particularly for reductive carbonylation, in achieving the optimum performance.
- Barnard, Christopher F.J.
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p. 566 - 574
(2013/01/03)
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- Alkoxycarbonylation of aryl iodides catalyzed by Pd with a thiourea type ligand under balloon pressure of CO
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Palladium-catalyzed alkoxycarbonylation of aryl iodides with a thiourea-oxazoline type ligand has been achieved under mild conditions. Various functional groups were tolerated and the yields were from moderate to excellent.
- Liu, Jing,Liang, Bo,Shu, Dongxu,Hu, Yanhe,Yang, Zhen,Lei, Aiwen
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p. 9581 - 9584
(2008/12/22)
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- An efficient catalyst for PD-catalyzed carbonylation of aryl arenesulfonates
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(Chemical Equation Presented) Aryl carboxylic esters were synthesized by Pd-catalyzed carbonylation of aryl p-fluorobenzenesulfonates or -tosylates. A unique Josiphos ligand was discovered through high-throughput catalyst screening, which was the key for the successful carbonylation of various substrates. This catalyst is effective and works well for both electron-rich and electron-poor aryl arenesulfonates. Isolated yields of up to 90% were obtained for aryl p-fluorobenzenesulfonates and -tosylates.
- Cai, Chaoxian,Rivera, Nelo R.,Balsells, Jaume,Sidler, Rick R.,McWilliams, J. Christopher,Shultz, C. Scott,Sun, Yongkui
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p. 5161 - 5164
(2007/10/03)
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- Palladium-catalyzed cross-coupling reaction of arylboronic acids with chloroformate or carbamoyl chloride
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The first palladium-catalyzed cross-coupling reaction between substituted arylboronic acids and chloroformate or carbamoyl chloride is described. One-carbon homologation from arylboronic acids was achieved to give corresponding esters or amides in good yi
- Duan, Ya-Zhen,Deng, Min-Zhi
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p. 355 - 357
(2007/10/03)
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- 1,2,4-Trioxepanes: Redox-cleavable protection for carbonyl groups
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(Chemical Equation Presented) 1,2,4-trioxepanes, readily prepared and easily handled derivatives of aldehydes and ketones, are stable to a variety of synthetic conditions and yet easily deblocked with Zn/HOAc or Mg/MeOH to regenerate the parent carbonyl. Trioxepanes may provide an alternative to 1,3-dithianes for acid-stable protection of carbonyl groups.
- Ahmed, Aqeel,Dussault, Patrick H.
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p. 3609 - 3611
(2007/10/03)
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- Convenient Processes for the Synthesis of Aromatic Ketones from Aryl Bromides and Carboxylic Anhydrides Using a Cobalt Catalysis
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The cross-coupling of various para- and meta-substituted aromatic bromides, mostly bearing sensitive moieties, with several carboxylic acid anhydrides is reported. This reaction can be carried out in two steps, by forming an aromatic organozinc reagent via cobalt catalysis in the first step, or even more interestingly in a single step, also by using a cobalt-based catalyst. The aromatic ketones are obtained by these new, mild, and convenient methods in 30-79% yields versus starting aryl bromide. Results are also disclosed that suggest the role played by cobalt species in the coupling of organozinc reagents with electrophiles could be similar to those of more commonplace transition metal complexes.
- Kazmierski, Igor,Bastienne, Mylene,Gosmini, Corinne,Paris, Jean-Marc,Perichon, Jacques
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p. 936 - 942
(2007/10/03)
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- A novel preparation of methyl ketones through one-carbon homologation of aldehydes
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A novel two-step aldehyde homologation procedure for the preparation of methyl ketones has been developed, which involves the use of 1,1-dibromo-1-alkenes as precursors and zinc metal as mediator in near-critical water.
- Wang, Lei,Li, Pinhua,Yan, Jincan,Wu, Zhongzhi
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p. 4685 - 4688
(2007/10/03)
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- Palladium-catalyzed reaction of aryl iodides with acetic anhydride. A carbon monoxide-free synthesis of acetophenones
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(Matrix presented) The palladium-catalyzed reaction of aryl iodides with acetic anhydride provides a straightforward and experimentally simple carbon monoxide-free route to acetophenones. The reaction tolerates a wide range of funcfionalized aryl iodides. Acetophenones are isolated in excellent yield with a variety of neutral, slightly electron-rich, and slightly electron-poor aryl iodides, whereas moderate yields are obtained with aryl iodides containing strongly electron-withdrawing substituents.
- Cacchi, Sandro,Fabrizi, Giancarlo,Gavazza, Federica,Goggiamani, Antonella
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p. 289 - 291
(2007/10/03)
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- A convenient method for the preparation of aromatic ketones from acyl chlorides and arylzinc bromides using a cobalt catalysis
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Aromatic ketones are synthesized efficiently via cobalt catalyzed cross-coupling reaction between arylzinc bromides and acid chlorides. Arylzinc bromides prepared chemically via a cobalt catalysis undergo coupling without additional catalyst unlike their electrochemical analogs.
- Fillon, Hyacinthe,Gosmini, Corinne,Périchon, Jacques
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p. 8199 - 8202
(2007/10/03)
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- Pure acetonitrile as solvent for the efficient electrochemical conversion of aryl bromides in organozinc species and their coupling reaction with acetyl chloride
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Conversion of functionalized aryl bromides in an electrochemical cell fitted with a sacrificial anode and in the presence of cobalt bromide without ligand in acetonitrile as solvent affords the corresponding organozinc species in good yields. Their coupling with acetyl chloride is efficient using a palladium catalyst.
- Fillon, Hyacinthe,Le Gall, Erwan,Gosmini, Corinne,Périchon, Jacques
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p. 5941 - 5944
(2007/10/03)
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- Palladium-catalyzed alkoxycarbonylation of aryl p-toluenesulfonate
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Methyl- and ethyl arylcarboxylates were synthesized by palladium-catalyzed alkoxycarbonylation of various aryl p-toluenesulfonates (tosylates). Yields were highly dependent on the substituent of aryl tosylates and phosphine ligands used. Ethoxycarbonylation of 4-acetylphenyl tosylate by the use of a bisphosphine ligand gave ethyl 4-acetylbenzoate in quite satisfactory yields.
- Kubota, Yoshihiro,Nakada, Shigekuni,Sugi, Yoshihiro
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p. 183 - 185
(2007/10/03)
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- A Convenient Preparation of Functionalized Arylzinc Compounds by the Reaction of Zinc/Silver-Graphite with Aryl Iodides.
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Aryl- and hetero-aryl iodides react under very mild conditions (THF, 25 deg C) with a Zn(Ag) couple deposited on graphite leading to the corresponding zinc reagents in excellent yields.In the presence of CuCN*2LiCl or catalytic amounts of Pd(O), these unsaturated zinc species can be acylated, allylated or coupled with iodoalkenes.
- Fuerstner, Alois,Singer, Robert,Knochel, Paul
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p. 1047 - 1050
(2007/10/02)
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- A new method for the regioselective synthesis of β-enamino acid derivatives
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A mild, simple and efficient route to β-enamino imidazole carbonilic derivatives 3 by reaction of ketimines with N,N′-carbonyl diimidazole in the presence of boron triflouride as catalyst has been developed. The conversion of 3 to esters has also been explored.
- Fustero, Santos,Diaz, Ma. Dolores,Carlon, Raquel Perez
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p. 725 - 728
(2007/10/02)
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- TRANSITION METAL COMPLEX CATALYZED CARBONYLATION OF ORGANIC HALIDES IN THE PRESENCE OF MOLECULAR SIEVES INSTEAD OF BASE
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In the presence of molecular sieves under base free conditions organic halides are successfully carbonylated under carbon monoxide pressure with water or alcohols catalyzed by Co or Pd complex to generate the corresponding carboxylic acids or esters, respectively, in good yields.
- Urata, Hisao,Hu, Nan-Xing,Maekawa, Hisayuki,Fuchikami, Takamasa
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p. 4733 - 4736
(2007/10/02)
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- An Improved and Convenient Synthesis of Esters Using 1,1'-Carbonyldiimidazole and a Reactive Halide
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The esterification of carboxylic acid proceeded easily in a one-pot reaction with 1,1'-carbonyldiimidazole in the presence of a reactive halide under neutral reaction conditions in high yields. Keywords - esterification: 1,1'-carbonyldiimidazole; formylation; tert-butyl ester; imidazolium salt; one-pot reaction
- Kamijo, Tetsuhide,Harada, Hiromu,Iizuka, Kinji
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p. 5044 - 5047
(2007/10/02)
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