- A Novel Synthesis of β-Trichlorostannyl Ketones from Siloxycyclopropanes and Their Facile Dehydrostannation Affording 2-Methylene Ketones
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Site-selective ring cleavage of siloxycyclopropanes 2 with stannic chloride (SnCl4) leads to good yields of β-trichlorostannyl ketones 3.Subsequent treatment of 3 with dimethyl sulfoxide (Me2SO) in chloroform at 60 deg C results in the facile dehydrostannation to give good yields of 2-methylene ketones 4.
- Ryu, Ilhyong,Murai, Shinji,Sonoda, Noboru
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- Merging Halogen-Atom Transfer (XAT) and Cobalt Catalysis to Override E2-Selectivity in the Elimination of Alkyl Halides: A Mild Route towardcontra-Thermodynamic Olefins
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We report here a mechanistically distinct tactic to carry E2-type eliminations on alkyl halides. This strategy exploits the interplay of α-aminoalkyl radical-mediated halogen-atom transfer (XAT) with desaturative cobalt catalysis. The methodology is high-yielding, tolerates many functionalities, and was used to access industrially relevant materials. In contrast to thermal E2 eliminations where unsymmetrical substrates give regioisomeric mixtures, this approach enables, by fine-tuning of the electronic and steric properties of the cobalt catalyst, to obtain high olefin positional selectivity. This unprecedented mechanistic feature has allowed access tocontra-thermodynamic olefins, elusive by E2 eliminations.
- Zhao, Huaibo,McMillan, Alastair J.,Constantin, Timothée,Mykura, Rory C.,Juliá, Fabio,Leonori, Daniele
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supporting information
p. 14806 - 14813
(2021/09/18)
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- Chemoselective reduction of ?,¢-unsaturated carbonyl and carboxylic compounds by hydrogen iodide
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The selective reduction of ?,¢-unsaturated carbonyl compounds was achieved to produce saturated carbonyl compounds with aqueous HI solution. The introduction of an aryl group at an ? or ¢ position efficiently facilitated the reduction with good yield. The reaction was applicable to compounds bearing carboxylic acids and halogen atoms. Through the investigation of the reaction mechanism, it was found that Michael-type addition of iodide occurred to produce ¢-iodo compounds followed by the reduction of C-I bond via anionic and radical paths.
- Matsumoto, Shoji,Marumoto, Hayato,Akazome, Motohiro,Otani, Yasuhiko,Kaiho, Tatsuo
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p. 590 - 599
(2021/03/29)
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- Asymmetric Catalytic Epoxidation of Terminal Enones for the Synthesis of Triazole Antifungal Agents
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An enantioselective epoxidation of α-substituted vinyl ketones was realized to construct the key epoxide intermediates for the synthesis of various triazole antifungal agents. The reaction proceeded efficiently in high yields with good enantioselectivities by employing a chiral N,N′-dioxide/ScIII complex as the chiral catalyst and 35% aq. H2O2 as the oxidant. It enabled the facile transformation for optically active isavuconazole, efinaconazole, and other potential antifungal agents.
- Feng, Xiaoming,He, Qianwen,Liu, Xiaohua,Zhang, Dong,Zhang, Fengcai
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supporting information
p. 6961 - 6966
(2021/09/11)
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- Cobalt(II)porphyrin-Mediated Selective Synthesis of 1,5-Diketones via an Interrupted-Borrowing Hydrogen Strategy Using Methanol as a C1 Source
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A novel cobalt(II)porphyrin-mediated acceptorless dehydrogenation of methanol is reported for the first time. This methodology has been applied for the coupling of a variety of ketones with methanol to produce 1,5-diketones along with H2 and H2O as the environment friendly byproducts. This paradigm was also demonstrated for a one-pot synthesis of substituted pyridines using a sequential addition protocol where the 1,5-diketones were generated in situ. From many experiments including those involving deuterium labeling, it is proposed that protonated cobalt(II)porphyrin methoxide complex acts as an intermediate to generate formaldehyde along with a metal hydride.
- Biswal, Priyabrata,Samser, Shaikh,Nayak, Prakash,Chandrasekhar, Vadapalli,Venkatasubbaiah, Krishnan
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p. 6744 - 6754
(2021/05/29)
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- Palladium-Catalyzed Synthesis of α-Methyl Ketones from Allylic Alcohols and Methanol
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One-pot synthesis of α-methyl ketones starting from 1,3-diaryl propenols or 1-aryl propenols and methanol as a C1 source is demonstrated. This one-pot isomerization-methylation is catalyzed by commercially available Pd(OAc)2 with H2O as the only by-product. Mechanistic studies and deuterium labelling experiments indicate the involvement of isomerization of allyl alcohol followed by methylation through a hydrogen-borrowing pathway in these isomerization-methylation reactions.
- Biswal, Priyabrata,Chandrasekhar, Vadapalli,Meher, Sushanta Kumar,Samser, Shaikh,Venkatasubbaiah, Krishnan
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supporting information
(2021/11/01)
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- Palladium-Mediated Tandem Isomerization-Methylenation of Allyl Alcohols: One-Pot Synthesis of 1,5-Diketones
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A novel methodology for the synthesis of 1,5-diketones through a one-pot isomerization-methylenation of a variety of allylic alcohols has been established for the first time. This methodology utilizes commercially available palladium acetate and easily accessible BINOL phosphoric acid. Both isomerization of allylic alcohol and oxidation of methanol occurred through a single catalyst. The practical utility of the methodology has been shown by synthesizing substituted pyridines via sequential addition. Mechanistic investigation reveals the isomerization of allylic alcohols to the corresponding ketone, which ultimately undergoes methylenation, leading to 1,5-diketones, having H2 and H2O as the only byproduct.
- Samser, Shaikh,Mohapatra, Omkar,Biswal, Priyabrata,Venkatasubbaiah, Krishnan
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p. 13744 - 13753
(2021/10/12)
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- Nickel-Catalyzed C(sp3)-H Functionalization of Benzyl Nitriles: Direct Michael Addition to Terminal Vinyl Ketones
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An efficient nickel(0)-catalyzed addition of benzyl nitriles to terminal vinyl ketones via C(sp3)-H functionalization has been developed. The reaction provides a novel and efficient protocol for the synthesis of α-functionalized benzyl nitriles with a wide range of structural diversity under mild reaction conditions while obviating the use of a strong base. The work might be potentially useful toward the development of an enantioselective variant using chiral nitrogen ligands.
- Zhang, Ninghui,Zhang, Chunli,Hu, Xiaoping,Xie, Xin,Liu, Yuanhong
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supporting information
p. 6004 - 6009
(2021/07/31)
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- Bromomethyl Silicate: A Robust Methylene Transfer Reagent for Radical-Polar Crossover Cyclopropanation of Alkenes
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A general protocol for visible-light-induced cyclopropanation of alkenes was developed with bromomethyl silicate as a methylene transfer reagent, offering a robust tool for accessing highly valuable cyclopropanes. In addition to α-aryl or methyl-substituted Michael acceptors and styrene derivatives, the unactivated 1,1-dialkyl ethylenes were also shown to be viable substrates. Apart from realizing the cyclopropanation of terminal alkenes, the methyl transfer reaction has been further demonstrated to be amenable to the internal olefins. The photocatalytic cyclopropanation of 1,3-bis(1-arylethenyl)benzenes was also achieved, giving polycyclopropane derivatives in excellent yields. With late-stage cyclopropanation as the key strategy, the synthetic utility of this transformation was also demonstrated by the total synthesis of LG100268.
- Luo, Wenping,Fang, Yewen,Zhang, Li,Xu, Tianhang,Liu, Yongjun,Li, Yan,Jin, Xiaoping,Bao, Jiakan,Wu, Xiaodong,Zhang, Zongyong
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supporting information
p. 1778 - 1781
(2020/03/11)
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- β-Borylation of conjugated carbonyl compounds with silylborane or bis(pinacolato)diboron catalyzed by Au nanoparticles
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Conjugated aldehydes and ketones undergo reaction with Me2PhSiBpin (pin: pinacolato) catalyzed by Au nanoparticles supported on TiO2 forming exclusively the β-borylation products, via the intermediate formation of the labile silaboration adducts. This chemoselectivity pathway is complementary to the so far known analogous reaction catalyzed by other metals, where β-silylation occurs instead. β-Borylation also occurs with pinBBpin under identical reaction conditions in a variety of conjugated carbonyl compounds, including esters and amides which are unreactive in their attempted Au-catalyzed silaboration. This journal is
- Fragkiadakis, Michael,Kidonakis, Marios,Stratakis, Manolis
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supporting information
p. 8921 - 8927
(2020/11/23)
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- Br?nsted Base-Catalyzed Transformation of α,β-Epoxyketones Utilizing [1,2]-Phospha-Brook Rearrangement for the Synthesis of Allylic Alcohols Having a Tetrasubstituted Alkene Moiety
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A stereoselective transformation of α,β-epoxyketones into alkenylphosphates having a hydroxymethyl group on the β-carbon was established by utilizing the [1,2]-phospha-Brook rearrangement under Br?nsted base catalysis. The reaction involves the catalytic generation of an α-oxygenated carbanion located at the α-position of an epoxide moiety through the [1,2]-phospha-Brook rearrangement and the following epoxide opening. Further transformation of the alkenylphosphates by the palladium-catalyzed cross-coupling reaction with Grignard reagents provided allylic alcohols having a stereodefined all-carbon tetrasubstituted alkene moiety.
- Kondoh, Azusa,Tasato, Naoko,Aoki, Takuma,Terada, Masahiro
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supporting information
p. 5170 - 5175
(2020/07/04)
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- Structure-activity relationships of novel dithiocarbamates containing α,β-unsaturated ketone fragment as potent anticancer agents
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Based on the structure of novel lead compound 8 discovered by our group, systematic structural modification was carried out. A series of compound 8’s derivatives were synthesized and evaluated for their activities against human non-small cell lung cancer cell line H460. Among them, twelve compounds showed significant proliferation inhibition activities with IC50 values 50 values 50 values of 12r achieved 63 nM and 66 nM, respectively. Meanwhile, our research results also revealed the following structure-activity relationships: (a) different substitutions on the benzene ring or heteroaromatic rings greatly effect on the activity; (b) the presence of α,β-unsaturated ketone fragment is favorable for the activity; (c) the receptor cavity binding with amine moiety might be a relatively small hydrophobic cavity. These results will be valuable for the further development of this novel kind of dithiocarbamates.
- Wang, Yuanqiang,Li, Ridong,Zhang, Han,Zhang, Zhiyong,Wang, Xin,Ge, Zemei,Li, Runtao
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p. 1027 - 1038
(2019/05/21)
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- Photoenzymatic Catalysis Enables Radical-Mediated Ketone Reduction in Ene-Reductases
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Flavin-dependent ene-reductases (EREDs) are known to stereoselectively reduce activated alkenes, but are inactive toward carbonyls. Demonstrated here is that in the presence of photoredox catalysts, these enzymes will reduce aromatic ketones. Mechanistic experiments suggest this reaction proceeds through ketyl radical formation, a reaction pathway that is distinct from the native hydride-transfer mechanism. Furthermore, this reactivity is accessible without modification of either the enzyme or cofactors, allowing both native and non-natural mechanisms to occur simultaneously. Based on control experiments, we hypothesize that binding to the enzyme active site attenuates the reduction potential of the substrate, enabling single-electron reduction. This reactivity highlights opportunities to access new catalytic manifolds by merging photoredox catalysis with biocatalysis.
- Sandoval, Braddock A.,Kurtoic, Sarah I.,Chung, Megan M.,Biegasiewicz, Kyle F.,Hyster, Todd K.
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supporting information
p. 8714 - 8718
(2019/05/28)
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- Photocatalytic C(sp3)?H Activation towards α-methylenation of Ketones using MeOH as 1 C Source Steering Reagent
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Unprecedented direct access to terminal enones via α-methylenation of aryl ketones to form C=C bond is achieved under visible-light conditions using methanol as one carbon source substrate and solvent as well. The reaction involves Cu@g-C3N4-catalysed in situ oxidation of methanol into formaldehyde followed by dehydrative cross aldol type reaction. Various aryl ketones react efficiently with MeOH, producing α,β-unsaturated carbonyl compounds only in 4–8 h at room temperature in excellent yield (84–97%). Operational simplicity, wide substrate scope, ambient reaction conditions, visible-light photocatalysis and novel application of MeOH as methylene donor substrate are the salient features making the envisaged protocol mild, efficient and green alternative to the existing methods for synthesis of such fine chemicals. (Figure presented.).
- Verma, Fooleswar,Shukla, Prashant,Bhardiya, Smita R.,Singh, Manorama,Rai, Ankita,Rai, Vijai K.
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supporting information
(2019/02/05)
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- One-Pot Conversion of Allylic Alcohols to α-Methyl Ketones via Iron-Catalyzed Isomerization-Methylation
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A one-pot iron-catalyzed conversion of allylic alcohols to α-methyl ketones has been developed. This isomerization-methylation strategy utilized a (cyclopentadienone)iron(0) carbonyl complex as precatalyst and methanol as the C1 source. A diverse range of allylic alcohols undergoes isomerization-methylation to form α-methyl ketones in good isolated yields (up to 84% isolated yield).
- Latham, Daniel E.,Polidano, Kurt,Williams, Jonathan M. J.,Morrill, Louis C.
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supporting information
p. 7914 - 7918
(2019/10/16)
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- Indium(III)-Catalyzed Hydration and Hydroalkoxylation of α,β-Unsaturated Ketones in Aqueous Media
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The hydration of α,β-unsaturated ketones with water proceeded efficiently in the presence of In(OTf)3 (20 mol%) in aqueous media to afford synthetically versatile β-hydroxyketones in moderate to good yields with good functional group compatibility. The method also can be extended to the hydroalkoxylation of α,β-unsaturated ketones with various alcohols for the efficient synthesis of β-alkoxyketones as well as tetrahydrofuran derivatives. (Figure presented.).
- Yun, Jin-Jin,Zhi, Man-Ling,Shi, Wen-Xiao,Chu, Xue-Qiang,Shen, Zhi-Liang,Loh, Teck-Peng
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supporting information
p. 2632 - 2637
(2018/05/30)
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- Chromium(III)-Catalyzed Addition of Water and Alcohol to α,β-Unsaturated Ketones for the Synthesis of β-Hydroxyl and β-Alkoxyl Ketones in Aqueous Media
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An efficient chromium(III) chloride-catalyzed Michael-type reaction of water or alcohol with α,β-unsaturated ketones is developed. A variety of α,β-unsaturated ketones effectively reacted with either water or alcohols to give the corresponding β-hydroxyl ketones or β-alkoxyl ketones in modest to high yields with excellent compatibility to various functional groups. The approach was further utilized for the preparation of synthetically useful compounds containing tetrahydrofuran skeleton.
- Yun, Jin-Jin,Liu, Xuan-Yu,Deng, Wei,Chu, Xue-Qiang,Shen, Zhi-Liang,Loh, Teck-Peng
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p. 10898 - 10907
(2018/09/06)
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- Visible-Light-Mediated Rose Bengal-Catalyzed α-Hydroxymethylation of Ketones with Methanol
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A visible-light-mediated α-hydroxymethylation of ketones using methanol as the hydroxymethylating reagent has been developed. Using 1 mol% rose bengal as the photosensitizer and air as the green oxidant, the reactions proceeded smoothly at room temperature. Experimental studies indicate the reaction proceeded via a radical pathway. (Figure presented.).
- Yang, Jingya,Xie, Dongtai,Zhou, Hongyan,Chen, Shuwen,Duan, Jiaokui,Huo, Congde,Li, Zheng
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p. 3471 - 3476
(2018/09/12)
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- Method for synthesizing alpha,beta-unsaturated ketone compounds from dimethyl sulfoxide and ketone compounds
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The invention discloses a method for synthesizing alpha,beta-unsaturated ketone compounds from dimethyl sulfoxide and ketone compounds. According to the method, dimethyl sulfoxide and ketone compoundsare subjected to a one-pot reaction in the presence of carboxylate and persulfate so as to produce the alpha,beta-unsaturated ketone compounds. The method uses dimethyl sulfoxide as a methylenation reagent and employs a one-pot process for high-selectivity high-yield synthesis of the alpha,beta-unsaturated ketone compounds from the ketone compounds; and the method is simple to operate, low in cost, friendly to environment and beneficial for industrial production.
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Paragraph 0047-0049; 0131-0137
(2018/03/24)
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- Cobalt-Catalyzed α-Methoxymethylation and Aminomethylation of Ketones with Methanol as a C1 Source
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Using methanol as a sustainable C1 source, cobalt-catalyzed α-methoxymethylation and α-aminomethylation of ketones have been developed. With cheap CoCl2·6H2O as catalyst and TBHP as oxidant, the methoxymethylated products were obtained within a short reaction time in up to 91% yield. Based on the observed reversibility of methoxy adduct to enone, the α-aminomethylation of ketones was then achieved by a one-pot methylenation/aza-Michael addition sequence. In addition, an easy way to convert α-methoxymethyl ketones to α-aminomethyl ketones has been discovered.
- Yang, Jingya,Chen, Shuwen,Zhou, Hongyan,Wu, Chengqi,Ma, Ben,Xiao, Jianliang
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supporting information
p. 6774 - 6779
(2018/10/25)
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- Solvent free, light induced 1,2-bromine shift reaction of α-bromo ketones
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Photolysis of α-bromopropiophenones in acetonitrile results in formation of β-bromopropiophenones with good product selectivity, which can be coined as 1,2-Br shift reaction. The product selectivity increases when the reaction is done in neat or solid state, where only the 1,2-Br shift product is formed in some cases. The reaction is suggested to proceed by C–Br bond homolysis to give a radical pair, followed by disproportionation and conjugate addition of HBr to the α,β-unsaturated ketone intermediate. When the unsaturated intermediate is stabilized by an extra conjugation, the reaction stops at the stage, in which the unsaturated ketone becomes a major product. The synthetic method described in this research fits in a category of eco-friendly organic synthesis nicely since the reaction does not use volatile organic solvents and any other additives such as acid, base or metal catalysts, etc. Besides, the method fits into perfect atom economy, which does not give any side products. The synthetic method should find much advantage over other alternative methods to obtain β-bromo carbonyl compounds.
- An, Sejin,Moon, Da Yoon,Park, Bong Ser
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p. 6922 - 6928
(2018/10/24)
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- Synthesis method of terminal olefin type compound
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The invention discloses a synthesis method of a terminal olefin type compound. The synthesis method comprises the following steps: taking a phosphorus ylide compound as a raw material and carbon dioxide as a C1 synthon in an organic solvent; reacting in the presence of a reducing agent to prepare the terminal olefin type compound, wherein the mole ratio of the phosphorus ylide compound to the reducing agent is 1 to (1 to 6) and the pressure of carbon dioxide is 1 to 3atm. The synthesis method disclosed by the invention has the advantages of convenience for operation, moderate conditions, widesubstrate applicable range and high efficiency; the defects in the prior art are filled; the synthesis method takes the carbon dioxide as synthon and carbon dioxide can be effectively absorbed so thata greenhouse effect is effectively prevented.
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Paragraph 0054; 0056; 0057
(2018/09/21)
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- Transition-Metal-Free Reductive Deoxygenative Olefination with CO2
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A new transition-metal-free reductive deoxygenative olefination of phosphorus ylides with CO2, an abundant and sustainable C1 chemical feedstock, is described. This catalytic CO2 fixation afforded β-unsubstituted acrylates and vinyl ketones in good yields with broad scope and good functional group tolerance under mild reaction conditions. Cost-effective and easily handled polymethylhydrosiloxane was used as a reductant. Bis(silyl)acetal was proved to be the key intermediate in this reductive functionalization of CO2.
- Zhu, Dao-Yong,Li, Wen-Duo,Yang, Ce,Chen, Jie,Xia, Ji-Bao
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supporting information
p. 3282 - 3285
(2018/06/11)
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- A methylene compound of preparation method and its application (by machine translation)
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The invention discloses a methylene compound of preparation method and its application, relates to the field of organic synthesis, the process comprises: 1) in the presence of a three-valent metal salt catalyst, will arone compound and halogen methyl radical trialkyl ammonium salt dissolved in a solvent, 2) 80 - 130 °C reaction 1 - 4 hours, separated and purified α - the methyl radical is fragrant compounds, the reaction environment pollution is small, substrate and wide range of application. (by machine translation)
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Paragraph 0023-0024; 0031-0032; 0048-0049
(2017/11/16)
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- Transition metal-free C(sp3)-H bond coupling among three methyl groups
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A coupling of multiple C(sp3)-H bonds of the methyl group in methyl ketones with dimethyl sulfoxide is developed. This coupling allows the direct C(sp3)-H bond coupling among three methyl groups and affords one C-C bond and one CC bond under transition metal-free conditions. The value-added cyclized 3-methylthiomethyl chroman-4-ones can be synthesized through this method. A plausible mechanism is proposed.
- Liu, Yufeng,Zhan, Xi,Ji, Pengyi,Xu, Jingwen,Liu, Qiang,Luo, Weiping,Chen, Tieqiao,Guo, Cancheng
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supporting information
p. 5346 - 5349
(2017/07/10)
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- Transition Metal-Free α-Csp3-H Methylenation of Ketones to Form C=C Bond Using Dimethyl Sulfoxide as Carbon Source
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A direct α-Csp3-H methylenation of arylketones to form C=C bond using dimethyl sulfoxide as one-carbon source is achieved under transition metal-free reaction condition. Various aryl ketone derivatives react readily with DMSO, producing the α,β-unsaturated carbonyl compounds in yields of 42 to 90%. This method features a transition metal-free reaction condition, wide substrate scope and using DMSO as novel one-carbon source to form C=C bond, thus providing an efficient and expeditious approach to an important class of α,β-unsaturated carbonyl compounds. Based on the preliminary experiments, a plausible mechanism of this transformation is disclosed.
- Liu, Yu-Feng,Ji, Peng-Yi,Xu, Jing-Wen,Hu, Yu-Qun,Liu, Qiang,Luo, Wei-Ping,Guo, Can-Cheng
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p. 7159 - 7164
(2017/07/26)
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- Iodine(III)-Mediated Oxidative Hydrolysis of Haloalkenes: Access to α-Halo Ketones by a Release-and-Catch Mechanism
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An unprecedented iodine(III)-mediated oxidative transposition of vinyl halides has been accomplished. The products obtained, α-halo ketones, are useful and polyvalent synthetic precursors. There are only a handful of reported examples of the direct conversion of vinyl halides to their corresponding α-halo carbonyl compounds. Insights into the mechanism and demonstration that this synthetic transformation can be done under enantioselective conditions are reported.
- Jobin-Des Lauriers, Antoine,Legault, Claude Y.
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supporting information
p. 108 - 111
(2016/01/15)
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- Direct Photoredox-Catalyzed Reductive Difluoromethylation of Electron-Deficient Alkenes
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Photoredox-catalyzed reductive difluoromethylation of electron-deficient alkenes was achieved in one step under tin-free, mild and neutral conditions. This protocol affords a facile method to introduce RCF2 (R=H, Ph, Me, and CH2N3) groups at sites β to electron-withdrawing groups. It was found that TTMS (tris(trimethylsilyl)silane) served nicely as both the H-atom donor and the electron donor in the catalytic cycle. Experimental and DFT computational results provided evidence that RCF2 (R=H, Ph, Me) radicals are nucleophilic in nature.
- Tang, Xiao-Jun,Zhang, Zuxiao,Dolbier, William R.
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supporting information
p. 18961 - 18965
(2016/01/26)
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- Nazarov cyclization of divinyl and arylvinyl epoxides: Application in the synthesis of resveratrol-based natural products
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New variation in the Nazarov cyclization has been developed by preparing divinyl and arylvinyl epoxides as pentadienyl cation precursors for the first time. Highly substituted cyclopentadienes, hydrindienes, and indenes were synthesized to demonstrate the compatibility of this reaction with substrates bearing a variety of substitutions and having different types of epoxides. Application of this method in the synthesis of resveratrol-based natural products was also demonstrated.
- Sudhakar, Gangarajula,Satish, Kovela
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supporting information
p. 6475 - 6480
(2015/04/22)
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- Iron-catalyzed aerobic oxidation of allylic alcohols: The issue of C=C bond isomerization
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An aerobic oxidation of allylic alcohols using Fe(NO3) 3·9H2O/TEMPO/NaCl as catalysts under atmospheric pressure of oxygen at room temperature was developed. This eco-friendly and mild protocol provides a convenient pathway to the synthesis of stereodefined α,β-unsaturated enals or enones with the retention of the C-C double-bond configuration.
- Liu, Jinxian,Ma, Shengming
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supporting information
p. 5150 - 5153
(2013/11/06)
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- Kinetic resolution of aryl alkenylcarbinols catalyzed by Fc-PIP
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An effective kinetic resolution of a variety of aryl alkenylcarbinols catalyzed by nonenzymatic acyl transfer catalyst Fc-PIP was developed, affording corresponding unreacted alcohols in good to excellent ee value up to 99% and with selectivity factors up to 24.
- Hu, Bin,Meng, Meng,Jiang, Shanshan,Deng, Weiping
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experimental part
p. 1289 - 1294
(2012/08/28)
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- PROTEIN CROSSLINKING INHIBITOR AND USE OF THE SAME
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The present invention relates to: a ketone compound having transglutaminase-inhibiting activity, which is represented by the following Formula 1, 2, or 3: wherein R1 is a substituted or unsubstituted aryl or heterocyclyl group, R2, R3, and R4 are hydrogen atoms, n is 2, X is halogen, R5 and R6 independently represent a hydrogen atom or a substituted or unsubstituted C1-C10 alkyl, aryl, or aralkyl group, wherein R5 and R6 are not hydrogen atoms at the same time, or R5 and R6 may be taken together to form a saturated or unsaturated and substituted or unsubstituted heterocyclyl group containing a nitrogen atom (N); an inhibitor of protein crosslinking comprising the compound; and a composition for preventing or treating a protein-crosslinking causative disease, which comprises the compound or the protein crosslinking inhibitor.
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Page/Page column 26
(2012/11/08)
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- COMPOSITIONS AND PROCESSES OF PREPARING AND USING THE SAME
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The present invention relates to compositions, for example, the DBU/Hexafluoroacetone hydrate salt, and processes of preparing and using the same for the modification of chemical compounds via the release of trifluoroacetate. The DBU/Hexafluoroacetone hydrate salt can perform trifluoromethylation reactions on chemical compounds, such as carbonyl group-containing compounds.
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Page/Page column 43
(2012/10/08)
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- Catalytic ring expansion of vinyl oxetanes: Asymmetric synthesis of dihydropyrans using chiral counterion catalysis
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Acid Showdown! The first catalytic ring expansion of vinyl oxetanes to 3,6-dihydro-2H-pyrans is described. Copper(II) triflate emerged as the best catalyst for this new transformation, which has broad scope as demonstrated by the eighteen examples included. The symmetric vinyl oxetane substrate can be asymmetrically desymmetrized when using either chiral Lewis or Bronsted acids as catalysts. Copyright
- Guo, Boying,Schwarzwalder, Gregg,Njardarson, Jon T.
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supporting information; experimental part
p. 5675 - 5678
(2012/07/03)
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- METHOD FOR PRODUCING DIFLUOROCYCLOPROPANE COMPOUND
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Provided is a method for producing a difluorocyclopropane compound under milder reaction conditions and with high selectivity and high yield. The method for producing a difluorocyclopropane compound of the present invention is characterized by using sodium bromodifluoroacetate as a difluorocyclopropanation agent. With the disclosed method, a difluorocyclopropane compound can be produced under milder reaction conditions and with a higher conversion rate and a higher yield compared to conventional art. Further, by-products can be reduced significantly, thus allowing waste to be greatly reduced. Accordingly, the production method of the present invention is easy to implement industrially (can be employed on an industrial scale) and is thus extremely practical and useful.
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Page/Page column 10
(2012/11/08)
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- Exploiting the facile release of trifluoroacetate for the α-methylenation of the sterically hindered carbonyl groups on (+)-sclareolide and (-)-eburnamonine
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An efficient method for the α-methylenation of carbonyl groups is reported, and this transformation is accomplished by a facile elimination of trifluoroacetate during the formation of the olefin. This method represents an improvement beyond existing protocol in cases of steric hindrance, and we have demonstrated the utility of the process across a series of ketones, lactams, and lactones. Additionally, we have applied this method to produce semisynthetic derivatives of the natural products (+)-sclareolide and (-)-eburnamonine, in which the carbonyl group is proximal to bulky functional groups. Mechanistic insight is also provided from a time course of 19F NMR. Biological evaluation of the natural-product-derived enones led to the identification of a derivative of (-)-eburnamonine with significant cytotoxicity (LC50 = 14.12 ?M) in drug-resistant MDA-MB-231 breast cancer cells.
- Riofski, Mark V.,John, Jinu P.,Zheng, Mary M.,Kirshner, Julia,Colby, David A.
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experimental part
p. 3676 - 3683
(2011/06/24)
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- Efficient, direct α-methylenation of carbonyls mediated by diisopropylammonium trifluoroacetate
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A very efficient method for the direct α-methylenation of carbonyl compounds, with yields up to 99%, utilizing paraformaldehyde, diisopropylammonium trifluoroacetate, and catalytic acid or base, is presented.
- Bugarin, Alejandro,Jones, Kyle D.,Connell, Brian T.
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supporting information; experimental part
p. 1715 - 1717
(2010/07/06)
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- Synthesis of pyrazolines by a site isolated resin-bound reagents methodology
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The elaboration of biologically important 3,4-substituted pyrazolines was achieved by an organocatalysed aza-Michael/transimination domino sequence between hydrazones and enones making use of a mixture of heterogeneous resin-bound acid/base reagents. This methodology nicely illustrates the site isolation concept of supported reagents allowing the simultaneous use of otherwise destructive reactive functionalities. The Royal Society of Chemistry 2010.
- Gembus, Vincent,Bonnet, Jean-Jacquesrouen,Janin, Franoisrouen,Bohn, Pierre,Levacher, Vincent,Briere, Jean-Franois
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supporting information; experimental part
p. 3287 - 3293
(2010/08/21)
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- Aminodifluorosulfinium salts: Selective fluorination reagents with enhanced thermal stability and ease of handling
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Diethylaminodifluorosulfinium tetrafluoroborate (XtalFluor-E) and morpholinodifluorosulfinium tetrafluoroborate (XtalFluor-M) are crystalline fluorinating agents that are more easily handled and significantly more stable than Deoxo-Fluor, DAST, and their analogues. These reagents can be prepared in a safer and more cost-efficient manner by avoiding the laborious and hazardous distillation of dialkylaminosulfur trifluorides. Unlike DAST, Deoxo-Fluor, and Fluolead, XtalFluor reagents do not generate highly corrosive free-HF and therefore can be used in standard borosilicate vessels. When used in conjunction with promoters such as Et3N3HF, Et3N2HF, or DBU, XtalFluor reagents effectively convert alcohols to alkyl fluorides and carbonyls to gem-difluorides. These reagents are typically more selective than DAST and Deoxo-Fluor and exhibit superior performance by providing significantly less elimination side products.
- Lheureux, Alexandre,Beaulieu, Francis,Bennett, Christopher,Bill, David R.,Clayton, Simon,Laflamme, Franois,Mirmehrabi, Mahmoud,Tadayon, Sam,Tovell, David,Couturier, Michel
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supporting information; experimental part
p. 3401 - 3411
(2010/07/07)
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- Lewis base-catalyzed conjugate reduction and reductive aldol reaction of α,β-unsaturated ketones using trichlorosilane
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Lewis bases such as Ph3P=O and HMPA catalyze the 1,4-reduction of α,β-unsaturated ketones with trichlorosilane, and because the 1,2-reduction of aldehydes scarcely proceeded under the conditions, one-pot reductive aldol reactions with aldehydes were successfully achieved; preliminary studies using a chiral Lewis base revealed a high potential for enantioselective catalysis. The Royal Society of Chemistry.
- Sugiura, Masaharu,Sato, Norimasa,Kotani, Shunsuke,Nakajima, Makoto
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supporting information; experimental part
p. 4309 - 4311
(2009/03/12)
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- The cation exchange resin-promoted coupling of alkynes with aldehydes: one-pot synthesis of α,β-unsaturated ketones
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Alkynes undergo smooth coupling with aldehydes in the presence of Amberlyst-15 at room temperature to produce the corresponding α,β-unsaturated ketones in high yields with E-geometry. The use of an inexpensive, readily available, and recyclable cation exchange resin makes this method quite simple and convenient.
- Yadav,Subba Reddy,Vishnumurthy
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p. 4498 - 4500
(2008/09/21)
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- Polymer-supported synthesis of α- and β-hydroxyketones through the formation of 1,3-dithiane intermediates
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The synthesis of polymer-supported 2-monosubstituted 1,3-dithianes from soluble copolymers bearing 1,3-propanedithiol groups, their lithiation, reactions with electrophiles such as aldehydes, ketones, α,β- unsaturated ketones and oxiranes, and cleavage of
- Bertini, Vincenzo,Lucchesini, Francesco,Pocci, Marco,Alfei, Silvana,Idini, Barbara
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body text
p. 1141 - 1144
(2009/04/06)
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- Tandem oxidation/halogenation of aryl allylic alcohols under Moffatt-Swern conditions
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(Chemical Equation Presented) Aryl allylic alcohols are converted to halogenated unsaturated ketones or allylic halides using excess Moffatt-Swern reagent. Electron-poor aromatic rings favor formation of the halogenated ketone, while electron-donating substituents in the ortho or para positions favor formation of the allylic halide. The oxidation/halogenation reaction performs well with both oxalyl chloride and oxalyl bromide, providing access to the corresponding chlorides or bromides, respectively.
- Yin, Jiandong,Gallis, Christina E.,Chisholm, John D.
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p. 7054 - 7057
(2008/02/11)
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- Palladium-catalyzed reactions of arylboron compounds with carboxylic acid chlorides
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Reactions of sodium tetraarylborates and arylboronic acids with acyl chlorides in the presence of palladium salts afford non-symmetrical ketones in high yields under mild conditions.
- Korolev,Bumagin
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p. 364 - 369
(2007/10/03)
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- Preparation of α-methylene ketones by direct methylene transfer
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Four methods for the preparation of α-methylene ketones by direct methylene transfer are presented. The procedures were optimized in order to obtain high yields.
- Rodrigues, J. Augusto R.,Siqueira-Filho, Ezequias P.,De Mancilha, Moacir,Moran, Paulo J. S.
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p. 331 - 340
(2007/10/03)
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- A Convenient Method for Preparing Aromatic α,β-Unsaturated Ketones from α,β-Unsaturated Acyl Chlorides and Arylboronic Acids via Suzuki-Miyaura Type Coupling Reaction
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Aromatic α,β-unsaturated ketones are synthesized efficiently by palladium-catalyzed cross-coupling reaction of arylboronic acids with α,β-unsaturated acyl chlorides in the presence of K 3PO4 hydrate in toluene.
- Urawa, Yoshio,Nishiura, Katsutoshi,Souda, Shigeru,Ogura, Katsuyuki
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p. 2882 - 2885
(2007/10/03)
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- Dibromomethane as one-carbon source in organic synthesis: Microwave-accelerated α-methylenation of ketones with dibromomethane and diethylamine
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The reactivity of aryl alkyl ketone with a preheated mixture of dibromomethane and diethylamine is poor and gives an α-methylenation product in very low yield even under refluxing condition. It can be accelerated dramatically by microwave irradiation. Under microwave condition, the cyclic 1,3-dicarbonyls, aryl alkyl ketones, heteroaryl alkyl ketones and acyclic benzyl ketone give α-methylenation products in modest to good yields.
- Hon, Yung-Son,Hsu, Tzyy-Rong,Chen, Chun-Yan,Lin, Yi-Hui,Chang, Fong-Jong,Hsieh, Cheng-Han,Szu, Ping-Hui
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p. 1509 - 1520
(2007/10/03)
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- Palladium-catalyzed synthesis of aryl ketones from boronic acids and carboxylic acids activated in situ by pivalic anhydride
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A new palladium-catalyzed cross-coupling reaction between arylboronic acids and mixed anhydrides, generated in situ from carboxylic acids and pivalic anhydride, is presented. Optimization of the new catalyst and the reaction conditions led to the development of a convenient one-pot ketone synthesis directly from carboxylic and boronic acids in the presence of different (phosphane)palladium complexes in wet THF at 60 °C. Systematic studies were performed to elucidate the reaction mechanism of this transformation. The scope and the limitations of the new process are demonstrated by the synthesis of 33 functionalized ketones. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
- Goossen, Lukas J.,Ghosh, Keya
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p. 3254 - 3267
(2007/10/03)
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- Synthesis of 2-alkyl (and aryl)-1-aryl-2-propen-1-ones via m-CPBA mediated oxidation of γ-(benzotriazol-1-yl)allylic selenides
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Treatment of 2-alkyl (and aryl)-3-aryl-3-(benzotriazol-1-yl)allylic selenides with m-CPBA (1 equiv.) for 10 min in CH2Cl2 at rt gave 2-alkyl (and aryl)-1-aryl-2-propen-1-ones in excellent yields.
- Kim, Taehoon,Kim, Kyongtae
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p. 3021 - 3024
(2007/10/03)
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- Baker's yeast reduction of α-methyleneketones
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The bioreduction of α-methyleneketones, R1C(=O)C(=CH2)R2 (R1 = Me, Et, Pr, iso-Bu, Ph, CH2CH2Ph; R2 = Cl, Me, Et, n-Pr, iso-Pr, n-Bu, n-C6H13, Ph, CH2Ph), was mediated by baker's yeast (Saccharomyces cerevisiae) to obtain the corresponding α-methylketones. The R1 and R2 groups had a significant influence on the rate and enantioselectivity of the reductions. The rate of C=C bond reduction was higher than that of C=O bond reduction. Only α-methyleneketones having R1 = Me yielded α-methylketones in high enantioselectivity with e.e.s of 88-99%.
- Siqueira Filho, Ezequias P.,Rodrigues, J.Augusto R.,Moran, Paulo J.S.
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p. 847 - 852
(2007/10/03)
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