- ARYLCYCLOHEXYLAMINE DERIVATIVES AND THEIR USE IN THE TREATMENT OF PSYCHIATRIC DISORDERS
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Provided herein are arylcyclohexylamine derivatives and their use in the treatment of psychiatric disorders.
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Paragraph 0311; 0313
(2021/07/02)
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- Aerobic oxidation and oxidative esterification of alcohols through cooperative catalysis under metal-free conditions
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The ABNO@PMO-IL-Br material obtained by anchoring 9-azabicyclo[3.3.1]nonane-3-oneN-oxyl (keto-ABNO) within the mesopores of periodic mesoporous organosilica with bridged imidazolium groups is a robust bifunctional catalyst for the metal-free aerobic oxidation of numerous primary and secondary alcohols under oxygen balloon reaction conditions. The catalyst, furthermore, can be successfully employed in the first metal-free self-esterification of primary aliphatic alcohols affording valued esters.
- Karimi, Babak,Ghahremani, Mina,Vali, Hojatollah,Ciriminna, Rosaria,Pagliaro, Mario
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supporting information
p. 8897 - 8900
(2021/09/10)
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- Ir(NHC)-Catalyzed Synthesis of β-Alkylated Alcohols via Borrowing Hydrogen Strategy: Influence of Bimetallic Structure
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Multi N-heterocyclic carbene(NHC)-modified iridium catalysts were employed in the β-alkylation of alcohols; dimerization of primary alcohols (Guerbet reaction), cross-coupling of secondary and primary alcohols, and intramolecular cyclization of alcohols. Mechanistic studies of Guerbet reaction, including kinetic experiments, mass analysis, and density functional theory (DFT) calculation, were employed to explain the fast reaction promoted by bimetallic catalysts, and the dramatic reactivity increase of monometallic catalysts at the late stage of the reaction. (Figure presented.).
- Sung, Kihyuk,Lee, Mi-hyun,Cheong, Yeon-Joo,Kim, Yu Kwon,Yu, Sungju,Jang, Hye-Young
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p. 3090 - 3097
(2021/05/10)
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- A donor-acceptor complex enables the synthesis of: E -olefins from alcohols, amines and carboxylic acids
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Olefins are prevalent substrates and functionalities. The synthesis of olefins from readily available starting materials such as alcohols, amines and carboxylic acids is of great significance to address the sustainability concerns in organic synthesis. Metallaphotoredox-catalyzed defunctionalizations were reported to achieve such transformations under mild conditions. However, all these valuable strategies require a transition metal catalyst, a ligand or an expensive photocatalyst, with the challenges of controlling the region- and stereoselectivities remaining. Herein, we present a fundamentally distinct strategy enabled by electron donor-acceptor (EDA) complexes, for the selective synthesis of olefins from these simple and easily available starting materials. The conversions took place via photoactivation of the EDA complexes of the activated substrates with alkali salts, followed by hydrogen atom elimination from in situ generated alkyl radicals. This method is operationally simple and straightforward and free of photocatalysts and transition-metals, and shows high regio- and stereoselectivities.
- Chen, Kun-Quan,Shen, Jie,Wang, Zhi-Xiang,Chen, Xiang-Yu
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p. 6684 - 6690
(2021/05/31)
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- C(sp3)-H Bond Acylation with N -Acyl Imides under Photoredox/ Nickel Dual Catalysis
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A novel Ni/photoredox-catalyzed acylation of aliphatic substrates, including simple alkanes and dialkyl ethers, has been developed. The method combines C-N bond activation of amides with a radical relay mechanism involving hydrogen-atom transfer. The protocol is operationally simple, employs bench-stable N -acyl imides as acyl-transfer reagents, and permits facile access to alkyl ketones under very mild conditions.
- Kerackian, Taline,Reina, Antonio,Krachko, Tetiana,Boddaert, Hugo,Bouyssi, Didier,Monteiro, Nuno,Amgoune, Abderrahmane
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supporting information
p. 1531 - 1536
(2020/10/21)
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- Catalytic Asymmetric Acyloin Rearrangements of α-Ketols, α-Hydroxy Aldehydes, and α-Iminols by N, N′-Dioxide-Metal Complexes
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A highly enantioselective acyloin rearrangement of cyclic α-ketols has been developed with a chiral Al(III)-N,N′-dioxide complex as catalyst. This strategy provided an array of optically active 2-acyl-2-hydroxy cyclohexanones in moderate to good yields with high enantioselectivities. The asymmetric isomerizations of acyclic α-hydroxy aldehydes and α-iminols were achieved as well under modified conditions, affording the corresponding chiral α-hydroxy ketones and α-amino ketones in moderate results. Moreover, further transformations of product to enantioenriched diols were carried out.
- Dai, Li,Li, Xiangqiang,Zeng, Zi,Dong, Shunxi,Zhou, Yuqiao,Liu, Xiaohua,Feng, Xiaoming
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supporting information
p. 5041 - 5045
(2020/07/03)
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- Synergistic Activation of Amides and Hydrocarbons for Direct C(sp3)–H Acylation Enabled by Metallaphotoredox Catalysis
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The utilizations of omnipresent, thermodynamically stable amides and aliphatic C(sp3)?H bonds for various functionalizations are ongoing challenges in catalysis. In particular, the direct coupling between the two functional groups has not been realized. Here, we report the synergistic activation of the two challenging bonds, the amide C?N and unactivated aliphatic C(sp3)?H, via metallaphotoredox catalysis to directly acylate aliphatic C?H bonds utilizing amides as stable and readily accessible acyl surrogates. N-acylsuccinimides served as efficient acyl reagents for the streamlined synthesis of synthetically useful ketones from simple C(sp3)?H substrates. Detailed mechanistic investigations using both computational and experimental mechanistic studies were performed to construct a detailed and complete catalytic cycle. The origin of the superior reactivity of the N-acylsuccinimides over other more reactive acyl sources such as acyl chlorides was found to be an uncommon reaction pathway which commences with C?H activation prior to oxidative addition of the acyl substrate.
- Baik, Mu-Hyun,Choi, Seulhui,Hong, Soon Hyeok,Lee, Geun Seok,Won, Joonghee
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p. 16933 - 16942
(2020/08/03)
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- Iron-Catalyzed Cleavage Reaction of Keto Acids with Aliphatic Aldehydes for the Synthesis of Ketones and Ketone Esters
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The radical–radical coupling reaction is an important synthetic strategy. In this study, the iron-catalyzed radical–radical cross-coupling reaction based on the decarboxylation of keto acids and decarbonylation of aliphatic aldehydes to obtain valuable aryl ketones is reported for the first time. Remarkably, when tertiary aldehydes were used as carbonyl sources, ketone esters were selectively obtained instead of ketones. The gram-scale preparation of aryl ketone through this strategy was easily achieved by using only 3 mol % of the iron catalyst. As a proof-of-concept, the bioactive molecule flurprimidol was synthesized in two steps by using this strategy.
- Zhou, Fangyuan,Li, Lesong,Lin, Kao,Zhang, Feng,Deng, Guo-Jun,Gong, Hang
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supporting information
p. 4246 - 4250
(2020/03/11)
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- Method for preparing aryl ketone based on iron-catalyzed free radical-free radical coupling reaction such as ketonic acid decarboxylation and fatty aldehyde de-carbonylation
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The invention discloses a method for preparing an aryl ketone derivative based on a free radical-free radical cross-coupling reaction such as ketonic acid decarboxylation and fatty aldehyde de-carbonylation. The method comprises the following steps: reacting aryl-substituted ketonic acid with fatty aldehyde under the catalytic action of ferric triacetylacetonate to generate an aryl ketone derivative; the gram-grade reaction can be realized by the method only by using 3mol% of an iron catalyst; and the method has the advantages of no need of consumption of a large amount of a Lewis acid catalyst or a stoichiometric organic metal reagent, mild reaction conditions, one-step reaction, few by-products, wide substrate application range and scalable reaction, and overcomes the defects of large catalyst consumption, insufficient functional group tolerance, many by-products and the like in the prior art.
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Paragraph 0039-0040
(2020/05/05)
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- Decarboxylative Oxygenation via Photoredox Catalysis
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The direct conversion of aliphatic carboxylic acids to their dehomologated carbonyl analogues has been accomplished through photocatalytic decarboxylative oxygenation. This transformation is applicable to an array of carboxylic acid motifs, producing ketones, aldehydes, and amides in excellent yields. Preliminary results demonstrate that this methodology is further amenable to aldehyde substrates via in situ oxidation to the corresponding acid and subsequent decarboxylative oxygenation. We have exploited this strategy for the sequential oxidative dehomologation of linear aliphatic chains.
- Faraggi, Tomer M.,Li, Wei,MacMillan, David W. C.
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p. 410 - 415
(2019/12/24)
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- One-pot formal dehydrogenative ketone synthesis from aldehydes and non-activated hydrocarbons
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Ketones are a fundamental functionality found throughout a range of natural and synthetic compounds, making their synthesis essential throughout the chemical disciplines. Herein, we describe a one-pot synthesis of ketones via decatungstate-mediated formal dehydrogenative coupling between aldehydes and non-activated hydrocarbons. A variety of substituted benzaldehydes and cycloalkanes could be used in the optimized reaction to produce the desired ketones in moderate yields. The decatungstate photocatalyst functions in two reactions in this synthesis, catalyzing both the coupling and oxidation steps of the process. Notably, the reaction displays both high atom economy and sustainability, as it uses light and oxygen as key energy sources.
- Yahata, Kenzo,Yoshioka, Shin,Hori, Shuhei,Sakurai, Shu,Kaneko, Yuki,Hasegawa, Kai,Akai, Shuji
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p. 336 - 338
(2020/05/14)
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- Synthesis, absolute configuration and in vitro cytotoxicity of deschloroketamine enantiomers: rediscovered and abused dissociative anaesthetic
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In this study, we aim to determine differences in cytotoxicity of racemic deschloroketamine and its enantiomers. The synthesized racemate of this recently rediscovered and abused dissociative anaesthetic was resolved by chiral HPLC and the absolute configuration of the enantiomers was assigned using a combination of circular dichroism methods and single-crystal X-ray. Not only the absolute configuration, but also the most preferred conformers present in the crystal were successfully determined by electron and vibrational circular dichroism supported by ab initio calculations, and confirmed by X-ray. The in vitro cytotoxicity of racemic deschloroketamine and its enantiomers was determined for nine different types of cell lines. Generally, (S)-deschloroketamine exhibited higher cytotoxicity in the majority of cases. For human embryonic kidney cells (HEK 293T), the (S)-enantiomer reached the IC50 below 1 mM concentration and, in consequence, proved to be twice as potent as the (R)-enantiomer. On the other hand, live-cell fluorescence microscopy imaging at sub-IC50 concentrations provided evidence for only a minor effect of deschloroketamine racemate and enantiomers on endoplasmic reticulum stress and mitochondria morphology in neuroblastoma cells SH-SY5Y.
- Jurásek, Bronislav,Králík, Franti?ek,Rimpelová, Silvie,?ejka, Jan,Setni?ka, Vladimír,Ruml, Tomá?,Kucha?, Martin,Kohout, Michal
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p. 19360 - 19368
(2018/12/13)
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- Preparation method of aromatic ketone
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The invention discloses a preparation method of aromatic ketone. Under the effects of a palladium catalyst and a nitrogen-containing ligand, nitrile compounds and arylsulfonylhydrazide take desulfurization addition reaction in an organic solvent; after the reaction is completed, post treatment is performed to obtain aromatic ketone. The reaction is applicable to aromatic nitrile compounds, and isalso applicable to aliphatic nitrile compounds; the reaction realizes the wide substrate applicability and functional group tolerance; the potential application value is realized in the aspect of aryl-carbonyl building.
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Paragraph 0051; 0052; 0053; 0055
(2018/09/11)
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- Pd(II)-Catalyzed Denitrogenative and Desulfinative Addition of Arylsulfonyl Hydrazides with Nitriles
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A Pd(II)-catalyzed denitrogenative and desulfinative addition of arylsulfonyl hydrazides with nitriles has been successfully achieved under mild conditions. This transformation is a new method for the addition reaction to nitriles with arylsulfonyl hydrazides as arylating agent, thus providing an alternative synthesis of aryl ketones. The reported addition reaction is tolerant to many common functional groups, and works well in the presence of electron-donating and electron-withdrawing substituents. Notably, the reported denitrogenative and desulfinative addition was also appropriate for alkyl nitriles, making this newly developed transformation attractive.
- Meng, Mengting,Yang, Liangfeng,Cheng, Kai,Qi, Chenze
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p. 3275 - 3284
(2018/03/25)
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- Cyclopentane Formation from Flexible Precursors Using Samarium(II) Reagents
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Three efficient methods for five-membered ring carbocycle synthesis have been developed from simple starting materials using samarium(II) reagents. A Reformatsky aldol reaction proceeded efficiently with samarium(II) iodide using lithium bromide as an additive. A new intramolecular alkylation of a samarium enolate was realized with a pendant sulfonate ester leaving group. Pinacol cyclization of a simple diketone was also demonstrated giving a diol product in high stereoselectivity. A promising lead result has been established demonstrating enantioselectivity in a chiral ligand controlled Reformatsky aldol reaction.
- Aretz, Christopher D.,Escobedo, Humberto,Cowen, Bryan J.
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p. 1880 - 1884
(2018/05/09)
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- A Selective and Functional Group-Tolerant Ruthenium-Catalyzed Olefin Metathesis/Transfer Hydrogenation Tandem Sequence Using Formic Acid as Hydrogen Source
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A ruthenium-catalyzed transfer hydrogenation of olefins utilizing formic acid as a hydrogen donor is described. The application of commercially available alkylidene ruthenium complexes opens access to attractive C(sp3)-C(sp3) bond formation in an olefin metathesis/transfer hydrogenation sequence under tandem catalysis conditions. High chemoselectivity of the developed methodology provides a remarkable synthetic tool for the reduction of various functionalized alkenes under mild reaction conditions. The developed methodology is applied for the formal synthesis of the drugs pentoxyverine and bencyclane.
- Zieliński, Grzegorz K.,Majtczak, Jaros?awa,Gutowski, Maciej,Grela, Karol
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p. 2542 - 2553
(2018/03/09)
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- Palladium and visible-light mediated carbonylative Suzuki-Miyaura coupling of unactivated alkyl halides and aryl boronic acids
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Herein, a simple and efficient method for the palladium-catalyzed carbonylation of aryl boronic acids with unactivated alkyl iodides and bromides under visible-light irradiation, ambient temperature and low CO-pressure is presented. Notably, the procedure uses readily available equipment and an inexpensive palladium catalyst to generate the key alkyl radical intermediate. These mild conditions enabled the synthesis of a range of functionalized aryl alkyl ketones including the antipsychotic drug, melperone.
- Roslin, Sara,Odell, Luke R.
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supporting information
p. 6895 - 6898
(2017/07/10)
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- Oxidative Dehomologation of Aldehydes with Oxygen as a Terminal Oxidant
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A mild, efficient protocol for oxidative cleavage of C-C bonds in aldehydes has been developed that employs alkali metal hydrides as reagents and oxygen from air as a terminal oxidant. The method is applicable to a broad substrate range.
- Shipilovskikh, Sergei A.,Rubtsov, Aleksandr E.,Malkov, Andrei V.
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supporting information
p. 6760 - 6762
(2017/12/26)
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- Suzuki Coupling of Amides via Palladium-Catalyzed C–N Cleavage of N-Acylsaccharins
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A palladium-catalyzed cross-coupling of activated amides with arylboronic acids has been developed via C–N bond cleavage. This approach demonstrated high tolerance to a variety of alkyl, aryl, heterocyclic and vinyl substituents. Unsymmetrical ketones could be achieved in excellent yield under mild conditions with 1% catalyst loadings. (Figure presented.).
- Wu, Hongxiang,Li, Yue,Cui, Ming,Jian, Junsheng,Zeng, Zhuo
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supporting information
p. 3876 - 3880
(2016/12/16)
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- Nickel-Catalyzed Alkylation of Amide Derivatives
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We report the catalytic alkylation of amide derivatives, which relies on the use of nonprecious metal catalysis. Amide derivatives are treated with organozinc reagents, utilizing nickel catalysis, to yield ketone products. The methodology is performed at ambient temperature and is tolerant of variation in both coupling partners. A precursor to a nanomolar glucagon receptor modulator was synthesized using the methodology, underscoring the mild nature of this chemistry and its potential utility in pharmaceutical synthesis. These studies are expected to further promote the use of amides as synthetic building blocks.
- Simmons, Bryan J.,Weires, Nicholas A.,Dander, Jacob E.,Garg, Neil K.
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p. 3176 - 3179
(2016/07/06)
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- One-Pot Synthesis of Arylketones from Aromatic Acids via Palladium-Catalyzed Suzuki Coupling
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A palladium-catalyzed one-pot procedure for the synthesis of aryl ketones has been developed. Triazine esters when coupled with aryl boronic acids provided aryl ketones in moderate to excellent yields (up to 95%) in the presence of 1 mol % Pd(PPh3)2Cl2 for 30 min. (Chemical Equation Presented).
- Wu, Hongxiang,Xu, Baiping,Li, Yue,Hong, Fengying,Zhu, Dezhao,Jian, Junsheng,Pu, Xiaoer,Zeng, Zhuo
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p. 2987 - 2992
(2016/04/26)
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- A ketone the synthetic method of the compound of (by machine translation)
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The invention discloses a method for the synthesis of ketone compound, the aldehyde compound and cyclanes mixed or dissolved in organic solvent, in the microwave radiation and presence of radical initiator under the condition of the 140 [...] 180 °C reaction to obtain the target product ketone compound, in the synthesis method of the reaction equation: , Wherein R 1 is phenyl or substituted phenyl, substituted phenyl benzene ring substituted the base is the fluorine, chloro, bromo, methyl, methoxy, trifluoromethyl or hydroxy in one or more of, the position of the substituent on the benzene ring is ortho, meta or para position, as n the 1 [...] 4 integer between the, free-radical initiator is benzoyl peroxide, di-tert-butyl peroxide, or cumyl peroxide, organic solvent as the alkane or benzene. The invention discloses method for the synthesis of the raw material is cheap and easy to obtain, good atom economy, wide range of the application of substrates, and the like, is suitable for industrial production. (by machine translation)
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Paragraph 0027-0029
(2017/01/05)
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- Synthesis of Ketones through Microwave Irradiation Promoted Metal-Free Alkylation of Aldehydes by Activation of C(sp3)-H Bond
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In this paper, a novel methodology for the synthesis of ketones via microwave irradiation promoted direct alkylation of aldehydes by activation of the inert C(sp3)-H bond has been developed. Notably, the reactions were accomplished under metal-free conditions and used commercially available aldehydes and cycloalkanes as substrates without prefunctionalization. By using this novel method, an alternative synthetic approach toward the key intermediates for the preparation of the pharmaceutically valuable oxaspiroketone derivatives was successfully established.
- Zhang, Xinying,Wang, Zhangxin,Fan, Xuesen,Wang, Jianji
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p. 10660 - 10667
(2015/11/18)
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- Palladium catalyzed decarboxylative acylation of arylboronic acid with ethyl cyanoacetate as a new acylating agent: Synthesis of alkyl aryl ketones
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Palladium catalyzed acylation of arylboronic acid containing various functional groups was performed efficiently by ethyl cyanoacetate/substituted ethyl cyanoacetate as the acylating agent in aqueous triflic acid medium. The alkyl aryl ketones were obtained in good to excellent yields, first by addition of arylboronic acid to the nitrile group of ethyl cyanoacetate and their derivatives, followed by in situ decarboxylation of the resulting β-ketoester.
- Yousuf, Md,Das, Tuluma,Adhikari, Susanta
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p. 8763 - 8770
(2015/11/10)
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- In tandem or alone: A remarkably selective transfer hydrogenation of alkenes catalyzed by ruthenium olefin metathesis catalysts
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A system for transfer hydrogenation of alkenes, composed of a ruthenium metathesis catalyst and HCOOH, is presented. This operationally simple system can be formed directly after a metathesis reaction to effect hydrogenation of the metathesis product in a single-pot. These hydrogenation conditions are applicable to a wide range of alkenes and offer remarkable selectivity. This journal is
- Zieliski, Grzegorz Krzysztof,Samojlowicz, Cezary,Wdowik, Tomasz,Grela, Karol
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p. 2684 - 2688
(2015/04/14)
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- Continuous flow synthesis of ketones from carbon dioxide and organolithium or grignard reagents
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We describe an efficient continuous flow synthesis of ketones from CO 2 and organolithium or Grignard reagents that exhibits significant advantages over conventional batch conditions in suppressing undesired symmetric ketone and tertiary alcohol byproducts. We observed an unprecedented solvent-dependence of the organolithium reactivity, the key factor in governing selectivity during the flow process. A facile, telescoped three-step-one-flow process for the preparation of ketones in a modular fashion through the in-line generation of organometallic reagents is also established.
- Wu, Jie,Yang, Xiaoqing,He, Zhi,Mao, Xianwen,Hatton, T. Alan,Jamison, Timothy F.
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supporting information
p. 8416 - 8420
(2014/08/18)
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- Aldehydes and ketones formation: Copper-catalyzed aerobic oxidative decarboxylation of phenylacetic acids and α-hydroxyphenylacetic acids
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Aromatic aldehydes or ketones from copper catalyzed aerobic oxidative decarboxylation of phenylacetic acids and α-hydroxyphenylacetic acids have been synthesized. This reaction combined decarboxylation, dioxygen activation, and C-H bond oxidation steps in a one-pot protocol with molecular oxygen as the sole terminal oxidant. This reaction represents a novel decarboxylation of an sp3-hybridized carbon and the use of a benzylic carboxylic acid as a source of carbonyl compounds.
- Feng, Qiang,Song, Qiuling
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p. 1867 - 1871
(2014/03/21)
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- Pd(II)-Catalyzed decarboxylative cross-coupling of potassium aryltrifluoroborates with α-oxocarboxylic acids at room temperature
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A novel Pd-catalyzed decarboxylative cross-coupling of potassium aryltrifluoroborates with R-oxocarboxylic acids is performed at room temperature. This reaction provides an efficient access to aryl ketones under mild conditions.
- Li, Mingzong,Wang, Cong,Ge, Haibo
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supporting information; experimental part
p. 2062 - 2064
(2011/06/19)
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- Et2Zn-mediated rearrangement of bromohydrins
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(Chemical Equation Presented) A simple and highly efficient method for the rearrangement of bromohydrins mediated by Et2Zn to synthesize carbonyl compounds was described. Various β-bromo alcohols were treated with 0.6 equiv of Et2Zn to form a zinc complex in CH 2Cl2 at room temperature for 2 h, followed by 1,2-migration to give the corresponding carbonyl compounds. This remarkable and clean rearrangement is general for acyclic and cyclic bromohydrins, and a variety of ring-expansive and -contractive carbonyl compounds were obtained in good to excellent yields according to the feature of the starting bromohydrins. The functional group tolerance of organozinc reagents in this reaction will be useful in organic synthesis. The scope and limitations of this rearrangement process were also investigated.
- Li, Lezhen,Cai, Peijie,Guo, Qingxiang,Xue, Song
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p. 3516 - 3522
(2008/09/20)
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- Diisopropyloxy(η2-cyclopentene)titanium for the diastereoselective synthesis of various 1,2-disubstituted cyclopentanes
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The reaction of 3 equiv of cyclopentylmagnesium chloride with 2 equiv of titanium(IV) isopropoxide at low temperature (-70 to -50 °C) leads to the formation of 1 equiv of diisopropyloxy(η2-cyclopentene)titanium containing low amounts of the starting Grignard reagent. The sequential addition of two electrophiles onto this titanium complex involved as an intermediate in Kulinkovich-type reactions delivers various 1,2-disubstituted cyclopentane rings with generally high diastereoselectivity. Mechanistic considerations and possible extensions of this method are discussed.
- Cadoret, Frédéric,Retailleau, Pascal,Six, Yvan
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p. 7749 - 7753
(2007/10/03)
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- Oxidation of alcohols with hydrogen peroxide catalyzed by a new imidazolium ion based phosphotungstate complex in ionic liquid
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A new catalyst based on imidazolium and tungstate ion (tris(imidazolium)- tetrakis(diperoxotungsto)phosphate (3-)) has been synthesized and characterized by FT-IR spectroscopy. An efficient and environmentally friendly procedure is described for the catalyst recycling and easy product isolation for the oxidation of alcohols with hydrogen peroxide catalyzed by imidazolium ion-based phosphotungstate complex in ambient-temperature ionic liquid.
- Chhikara, Bhupender S.,Chandra, Ramesh,Tandon, Vibha
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p. 436 - 439
(2007/10/03)
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- Cp*Ru(PN) complex-catalyzed isomerization of allylic alcohols and its application to the asymmetric synthesis of muscone
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Highly efficient isomerization of allylic alcohols into saturated carbonyls is accomplished using the catalyst system of Cp*RuCl[Ph2P(CH2)2NH2-κ2-P,N]-KOt-Bu (Cp* = η5-C5(CH3)5) under mild conditions. Mechanistic consideration based on isotope-labeling experiments indicated the present reaction is applicable to the asymmetric isomerization of racemic sec-allylic alcohols with a prochiral olefin via dynamic kinetic resolution. A concise asymmetric synthesis of muscone has been achieved, where the asymmetric isomerization using an optically active ligand is a key reaction. Copyright
- Ito, Masato,Kitahara, Sachiko,Ikariya, Takao
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p. 6172 - 6173
(2007/10/03)
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- Transformation of 1,5- and 1,6-dienes to carbocycles by hydrozirconation and oxidation with cerium(IV) compounds
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Cyclopentane and cyclohexane derivatives are prepared from 1,5- and 1,6-dienes in a one pot procedure by hydrozirconation, then oxidation of the generated 5- and 6-alkenylzirconocene chlorides with ammonium hexanitratocerate.
- Azemi, Takushi,Kitamura, Mitsuru,Narasaka, Koichi
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p. 1339 - 1344
(2007/10/03)
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- Stereocontrol in hydride addition to ketone-derived chiral N-acylhydrazones
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Chiral N-acylhydrazones derived from various aldehydes and N-amino-4-benzyl-2-oxazolidinone have previously been shown to be effective for acyclic stereocontrol of intermolecular radical and allylsilane additions. Treatment of the propionaldehyde hydrazone with tributyltin hydride in the presence of boron trifluoride etherate led to rapid chemoselective reduction of the imine bond in high yield. Preparation of similar hydrazones from ketones led to E/Z isomer mixtures, usually in ratios of 4:1 or greater. Geometry of the C=N bond was assigned by steric compression shifts in 13C NMR spectra. Reduction with tributyltin hydride and boron trifluoride etherate afforded diastereomer mixtures in ratios very similar to the original E/Z isomer ratios. The chiral auxiliary blocked the opposite face of the C=N bond relative to a related process using a chelated Lewis acid. A stereocontrol model involving monodentate interaction of the N-acylhydrazone and boron trifluoride is consistent with the observed stereochemical outcome.
- Qin, Jun,Friestad, Gregory K.
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p. 6393 - 6402
(2007/10/03)
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- Investigations into the regioselective C-deuteration of acyclic and exocyclic enolates
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Results are reported on the regioselective C-deuteration of a series of related acyclic and exocyclic enolates derived from substituted aryl ketones. We comment on factors, such as the presence of additives and the structural nature of the enolate, that influence the observed C-deuteration and discuss the role of the deuterium donor. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
- Eames, Jason,Coumbarides, Gregory S.,Suggate, Michael J.,Weerasooriya, Neluka
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p. 634 - 641
(2007/10/03)
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- Syntheses and Binding Studies of New [(Aryl)(aryloxy)methyl]piperidine Derivatives and Related Compounds as Potential Antidepressant Drugs with High Affinity for Serotonin (5-HT) and Norepinephrine (NE) Transporters
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In a wide search program toward new, efficient, and fast-acting antidepressant drugs, we have prepared series of new compounds having an (aryl)(aryloxy)methyl moiety linked directly or through a methylene chain to different substituted and unsubstituted cycles (isoquinoline, piperazine, piperidine, tetrahydropyran, or cyclopentane). These compounds have been evaluated for their affinities for serotonin (5-HT) transporter (SERT) and 5-HT1A and 5-HT2A receptors. Racemic mixtures of 4-[(aryl)(aryloxy)methyl]piperidine derivatives showed much higher affinity values for SERT than fluoxetine and resulted in lack of affinity for 5-HT 1A and 5-HT2A receptors. Some of these racemic mixtures were resolved to their enantiomers and tested for binding to norepinephrine (NE) transporter (NET), dopamine (DA) transporter (DAT), and α2 receptor. Several of these enantiomers [(-)-15b, (-)-15j, (-)-15t, (+)-15u] displayed a dual binding profile with affinities for SERT and NET with K i i = 1.9 and 13.5 nM, respectively), and further pharmacological characterization is in progress for its evaluation as a antidepressant.
- Orjales, Aurelio,Mosquera, Ramón,Toledo, Antonio,Pumar, M. Carmen,García, Neftalí,Cortizo, Lourdes,Labeaga, Luis,Innerárity, Ana
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p. 5512 - 5532
(2007/10/03)
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- An alternative to the Swern oxidation
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A variety of alcohols have been oxidized under mild conditions by the DMSO-Ph3P·X2 complexes. The reaction does not produce any Pummerer product. A mechanism for the reaction is proposed.
- Bisai, Alakesh,Chandrasekhar,Singh, Vinod K.
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p. 8355 - 8357
(2007/10/03)
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- Synthesis and structure-activity relationships of potential anticonvulsants based on 2-piperidinecarboxylic acid and related pharmacophores
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Using N-(2,6-dimethyl)phenyl-2-piperidinecarboxamide (1) and N-(α-methylbenzyl)-2-piperidinecarboxamide (2) as structural leads, a variety of analogues were synthesised and evaluated for anticonvulsant activity in the MES test in mice. In the N-benzyl series, introduction of 3-Cl, 4-Cl, 3,4-Cl2, or 3-CF3 groups on the aromatic ring led to an increase in MES activity. Replacement of the α-methyl group by either i-Pr or benzyl groups enhanced MES activity with no increase in neurotoxicity. Substitution on the piperidine ring nitrogen led to a decrease in MES activity and neurotoxicity, while reduction of the amide carbonyl led to a complete loss of activity. Movement of the carboxamide group to either the 3- or 4-positions of the piperidine ring decreased MES activity and neurotoxicity. Incorporation of the piperidine ring into a tetrahydroisoquinoline or diazahydrinone nucleus led to increased neurotoxicity. In the N-(2,6-dimethyl)phenyl series, opening of the piperidine ring between the 1- and 6-positions gave the active norleucine derivative 75 (ED50 = 5.8 mg kg-1, TD50 = 36.4 mg kg-1, PI = 6.3). Replacement of the piperidine ring of 1 by cycloalkane (cyclohexane, cyclopentane, and cyclobutane) resulted in compounds with decreased MES activity and neurotoxicity, whereas replacement of the piperidine ring by a 4-pyridyl group led to a retention of MES activity with a comparable PI. Simplification of the 2-piperidinecarboxamide nucleus of 1 into a glycinecarboxamide nucleus led to about a six-fold decrease in MES activity. The 2,6-dimethylanilides were the most potent compounds in the MES test in each group of compounds evaluated, and compounds 50 and 75 should be useful leads in the development of agents for the treatment of tonic-clonic and partial seizures in man.
- Ho, Bin,Michael Crider,Stables, James P
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p. 265 - 286
(2007/10/03)
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- Oxidative decarboxylation of arylacetic acids mediated by peroxysulfur intermediate generated from 2-nitrobenzenesulfonyl chloride and superoxide
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The oxidative decarboxylation of aryl, α, α-diaryl, or arylalkylacetic acids has been achieved by a 2-nitrobenzenesulfonyl peroxy radical intermediate (I) generated by the reaction of 2-nitrobenzenesulfonyl chloride with potassium superoxide at -20°C in dry acetonitrile.
- Kim II, Yong,Kim, Yong Hae
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p. 639 - 642
(2007/10/03)
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- Direct formation of secondary and tertiary alkylzinc bromides and subsequent Cu(I)-mediated couplings
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Secondary and tertiary alkylzinc bromides can be generated from the direct oxidative addition of Rieke zinc to secondary and tertiary alkyl bromides in high yield. These organozinc reagents have been found to undergo copper-catalyzed conjugate addition, cross-coupling with acid chlorides, and carbocupration to activated alkynes.
- Rieke, Reuben D.,Hanson, Mark V.,Brown, Jeffrey D.,Niu, Q. Jason
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p. 2726 - 2730
(2007/10/03)
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- Direct formation of secondary and tertiary alkylzinc bromides
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The direct formation of secondary and tertiary alkylzinc bromides can be accomplished under mild conditions from the direct oxidative addition of Rieke zinc to secondary and tertiary alkyl bromides including remote functionalized halides.
- Hanson, Mark V.
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p. 7205 - 7208
(2007/10/02)
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- Photoinduced Electron Transfer (PET) Promoted Cross-coupling of Organoselenium and Organosilicon Compounds: a New Carbon-Carbon Bond Formation Strategy
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PET promoted cross-coupling of organoselenium compounds and silyl enol ethers is reported.
- Pandey, Ganesh,Sochanchingwung, R.
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p. 1945 - 1946
(2007/10/02)
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- Synthesis and evaluation of 4-alkylanilines as mammary tumor inhibiting aromatase inhibitors
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The 4-alkylanilines 1-20 were synthesized to elucidate the importance of the glutarimide moiety for the aromatase inhibiting activity of aminoglutethimide [3-(4-aminophenyl)-3-ethylpiperidine-2,6-dione, AG], the only non-steroidal aromatase inhibitor which is commercially available at present. The most interesting compounds were the (4-aminophenyl)cycloalkanes 4-6 (4, c-pentyl; 5, c-hexyl; 6, c-heptyl) and the 1-alkyl-1-(4-aminophenyl)cyclohexanes 1-3 (1, CH3; 2, C2H5; 3, n-C3H7). Derivatives 1-6 are stronger inhibitors of human placental aromatase than AG exhibiting relative potencies from 1.5 to 2.7 (AG≡1). For selectivity of action, the inhibition of desmolase (cholesterol side chain cleavage enzyme) was determined. Compounds 1-3 showed an inhibition comparable to AG, whereas compounds 4-6 exhibited no effect on desmolase. Being more potent and selective aromatase inhibitors in vitro, compounds 4-6, however, were not superior to AG in vivo, when the reduction of plasma estradiol concentration and the tumor inhibiting activity (PMSG-primed SD rats and DMBA-induced mammary carcinoma of the SD rat, postmenopausal model) were concerned.
- Hartmann,Batzl
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p. 537 - 544
(2007/10/02)
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- Ruthenium Complex Catalyzed Intermolecular Hydroacylation and Transhydroformylation of Olefins with Aldehydes
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Low-valent ruthenium complexes such as dodecacarbonyltriruthenium (Ru3(CO)12), (η4-1,5-cyclooctadiene)(η6-1,3,5-cyclooctatriene)ruthenium (Ru(COD)(COT)) and bis(η5-cyclooctadienyl)ruthenium showed high catalytic activity for the intermolecular hydroacylation of olefins with various aromatic and heteroaromatic aldehydes at 180-200 deg C for 24-48 h under an initial carbon monoxide pressure of 20 kg cm-2 to give unsymmetric ketones in moderate to good yields.In the reaction of 2-thiophenecarbaldehyde with cyclohexene, cyclohexyl 2-thienyl ketone was obtained in 62 percent yield.On the other hand, when the aliphatic aldehyde, heptanal, was treated with cyclohexene, the corresponding ketone was not obtained at all, and a transhydroformylation reaction proceeded; i.e., the formyl group of heptanal was apparently transformed to cyclohexene to give cyclohexanecarbaldehyde in 29 percent yield, together with their Tishchenko-type reaction products.
- Kondo, Teruyuki,Akazome, Motohiro,Tsuji, Yasushi,Watanabe, Yoshihisa
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p. 1286 - 1291
(2007/10/02)
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- N-Arylsulfonylamidines; Part 2. A New Synthesis of Ketones from N'-Tosylamidines and Organolithium Compounds
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Tertiary N'-arylsulfonylamidines readily react with organolithium compounds under simple conditions to afford carbonyl compounds.
- Clerici, Francesca,Gelmi, Maria Luisa,Rossi, Luisa Maria
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p. 1025 - 1027
(2007/10/02)
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- ANOMALOUS STEREOCHEMISTRY OF GASE-PHASE ACID-INDUCED RING OPENING IN 1-PHENYLCYCLOHEXENE OXIDE
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The first experimental evidence for an entropy-driven frontside displacement in a gas-phase cationic nucleophilic substitution has been provided by the results concerning the ring opening of 1-phenylcyclohexene oxide catalized by gaseous acids.
- Crotti, P.,Macchia, F.,Pizzabiocca, A.,Renzi, G.,Speranza, M.
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p. 3393 - 3396
(2007/10/02)
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- Ring Contraction of 2-Chlorocyclohexanone with Grignard Reagents
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The reaction of 2-chlorocyclohexanone with phenylmagnesium bromide in refluxing tetrahydrofuran unexpectedly afforded the ring-contracted product, cyclopentyl phenyl ketone, as the main product in moderate yield.The reactivities of several cyclic 2-haloketones were examined.Keywords - 2-chlorocyclohexanone; Grignard reaction; ring contraction; cyclopentyl phenyl ketone; solvent effect; THF; conformational isomer
- Hori, Mikio,Kataoka, Tadashi,Shimizu, Hiroshi,Imai, Eiji,Iwamura, Tatsunori,Maeda, Kaori
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p. 3599 - 3605
(2007/10/02)
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- APPLICATIONS of ORGANOLITHIUM and RELATED REAGENTS in SYNTHESIS. Part V. Directed Metallation of Secondary Picolin- and Isonicotinamides. A Useful Method for the Synthesis of 2,3- and 3,4-Disubstituted Pyridines, Including Furopyridin-3(1H)-one and Furopyridine-1(3H)-one
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The metallation reaction of N-methyl-, N-benzyl- and N-phenyl-amides (1a-c) and (2a-c) derived from picolinic and isonicotinic acids by BunLi in THF leading to the corresponding bis(N- and 3-)lithiated amides (3a-c) and (4a-c), are described.The N-phenylamides (anilides) (1c) and (2c), in comparison with the other aliphatic derivatives, demonstrate greater abilities to direct ortho lithiation at the 3-position of the pyridine ring, and give with very good yields bis(N- and 3-)lithiated anilides (3c) and (4c), respectively.The N-benzylamides (1b) and (2b) are ortho metallated under kinetic control at -78 deg C to form the bis(N- and 3-)lithiated benzylamides (3b) and (4b), but the organometallic intermediates rearrange at room temperature to give the thermodynamically more stable bis(N- and α-)lithiated amides (3g) and (4g) (benzyl-type anions).The generated carbanions (3c), (4c), (3g) and (4g) were trapped by a variety of electrophiles (e.g. alkyl halides and aldehydes).The synthesis of furopyridin-3(1H)-one (18) and furopyridin-(3H)-one (19) is included.
- Epsztajn, Jan,Bieniek, Adam,Plotka, Mieczyslaw W.
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p. 442 - 474
(2007/10/02)
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- Intramolecular Reactions. Part 12. Ring Size and Leaving Group Effects on Inter- and Intra-molecular Nucleophilic Substitution by Carbanions
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In cyclisations of aryl ο-halogenoalkyl ketones to aryl cycloalkyl ketones with base, cyclopropanes are formed up to 23000 times faster than cyclopentanes.Hydrogen-deuterium exchange experiments and very low bromide-chloride ratios (1.9) for three-membered ring formation are consistent with rate-determining deprotonation of the ketone.By contrast, in five-membered ring formation, hydrogen-deuterium exchange adjacent to the carbonyl group occurs much faster than cyclisation and the chloride-bromide ratio is 'normal' at 99.In formation of arylsulphonylcyclopropanes from arylsulphonylpropyl arenesulphonates, the Hammett ρ value for the leaving group is +1.7, and for intermolecular substitution by bis-sulphonyl stabilised carbanions, +1.2.Attempts to obtain ρLG values for five-membered ring formation were frustrated by competing intermolecular reactions.The results are discussed against the background of previous work on ring formation by intramolecular nucleophilic substitution.
- Bird, Roger,Griffiths, Gwerydd,Griffiths, Gwynfor F.,Stirling, Charles J. M.
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p. 579 - 584
(2007/10/02)
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