- Methylation Alkynylation of Terminal Alkenes via 1,2-Alkynyl Migration Using Dicumyl Peroxide as the Methyl Source
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The metal-free oxidative alkene methylation/alkynylation of 1,4-enyn-3-ols with an organic peroxide as the methyl source has been developed, which provides straightforward and practical access to the challenging quaternary-carbon-containing but-3-yn-1-one
- Qin, Yi-Qun,Chen, De,Liu, Liang,Zhang, Jia-Jia,Peng, Xin-Ju,Luo, Yong-Yue,Deng, Wei,Xiang, Jiannan
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p. 4700 - 4708
(2021/08/31)
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- General Synthesis of α-Alkyl Ynones from Morpholine Amides and 1-Copper(I) Alkynes Promoted by Triflic Anhydride
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The first general method for the synthesis of α-alkyl ynones was developed based on the strategy of electrophilic activation of amides. Its distinctive advantages are attributed to the use of air-stable "bare"1-copper(I) alkyne as a mild nucleophile witho
- Weng, Yunxiang,Min, Lin,Zeng, Xiaobao,Shan, Lidong,Wang, Xinyan,Hu, Yuefei
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p. 8296 - 8301
(2020/11/03)
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- Synthesis of C4-alkynylisoxazoles: Via a Pd-catalyzed Sonogashira cross-coupling reaction
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A Pd-catalyzed Sonogashira cross-coupling reaction for the synthesis of C4-alkynylisoxazoles from 3,5-disubsitituted-4-iodoisoxazoles and terminal alkynes was described, which could afford the corresponding products with high yield (up to 98%). The result
- Yang, Wen,Yao, Yongqi,Yang, Xin,Deng, Yingying,Lin, Qifu,Yang, Dingqiao
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p. 8894 - 8904
(2019/03/28)
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- Lewis-base-catalysed selective reductions of ynones with a mild hydride donor
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Ynones are efficiently reduced with a mild hydride donor in the presence of a catalytic amount of nucleophilic phosphines. The reactions are selective 1,2-reductions that give propargyl alcohols in yields of up to 96%. It is proposed that success in these reactions depends on the activation of ynones by a Lewis base catalyst. A protic additive plays a key role in suppressing the undesired reaction pathways and accelerating the 1,2-reductions.
- Sch?mberg,Zi,Vilotijevic
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supporting information
p. 3266 - 3269
(2018/04/05)
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- Complementary regioselective synthesis of 3,5-disubstituted isoxazoles from ynones
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Two regioselective synthetic routes towards 3,5-disubstituted isoxazoles from ynones are reported. One route takes place via first converting the ynones to ynone O-methyl oximes, followed by a palladium-catalyzed intramolecular cyclization. The other invo
- Liu, Xiaochen,Hong, Dongsub,She, Zhigang,Hersh, William H.,Yoo, Barney,Chen, Yu
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p. 6593 - 6606
(2018/10/05)
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- Pd-Catalyzed Cross-Coupling of Terminal Alkynes with Chromium(0) Fischer Carbene Complexes
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Alkyl chromium(0) carbene complexes typically undergo cycloadditions with alkynes to afford carbo- or heterocyclic compounds. In the presence of Pd catalyst, it is demonstrated that a traditional cycloaddition pathway is completely altered: instead of cyc
- Wang, Kang,Wu, Fengjin,Zhang, Yan,Wang, Jianbo
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supporting information
p. 2861 - 2864
(2017/06/07)
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- Alkynylation of Csp2 (O)–H Bonds Enabled by Photoredox-Mediated Hydrogen-Atom Transfer
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The development of new hydrogen-atom transfer (HAT) strategies within the framework of photoredox catalysis is highly appealing for its power to activate a desired C?H bond in the substrate leading to its selective functionalization. Reported here is the first photoredox-mediated hydrogen-atom transfer method for the efficient synthesis of ynones, ynamides, and ynoates with high regio- and chemoselectivity by direct functionalization of Csp2 (O)?H bonds. The broad synthetic application of this method has been demonstrated by the selective functionalization of C(O)?H bonds within complex molecular scaffolds.
- Mukherjee, Satobhisha,Garza-Sanchez, R. Aleyda,Tlahuext-Aca, Adrian,Glorius, Frank
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p. 14723 - 14726
(2017/10/18)
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- Oxidative coupling of tetraalkynyltin with aldehydes leading to alkynyl ketones
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The reaction of tetraalkynyltin with aldehydes was studied for the first time. The reaction was shown to proceed as a tandem process of nucleophilic addition of tin acetylide to aldehyde followed by Oppenauer-type oxidation of produced tin alcoholates, an
- Levashov, Andrey S.,Aksenov, Nicolai A.,Aksenova, Inna V.,Konshin, Valeriy V.
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p. 8297 - 8304
(2017/08/14)
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- Decarboxylative Alkynylation and Carbonylative Alkynylation of Carboxylic Acids Enabled by Visible-Light Photoredox Catalysis
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Visible-light-induced photocatalytic decarboxylative alkynylations of carboxylic acids have been developed for the first time. The reaction features extremely mild conditions, broad substrate scope, and avoids additional oxidants. Importantly, a decarboxy
- Zhou, Quan-Quan,Guo, Wei,Ding, Wei,Wu, Xiong,Chen, Xi,Lu, Liang-Qiu,Xiao, Wen-Jing
-
supporting information
p. 11196 - 11199
(2016/07/06)
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- Palladium- and solvent-free synthesis of ynones by copper(I)-catalyzed acylation of terminal alkynes with acyl chlorides under aerobic conditions
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Air-stable CuI/cryptand-22 complex was found to be a highly active catalyst for the solvent-free cross-coupling reaction of terminal alkynes with different acyl chlorides in the presence of Et3N as base to give the corresponding ynon
- Mohammadi, Elmira,Movassagh, Barahman,Navidi, Mozhgan
-
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- Synthesis of 3-carbonyl pyrazole-5-phosphonates via 1,3-dipolar cycloaddition of Bestmann-Ohira reagent with ynones
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The present work explores the hitherto unexplored reactivity of ynones as dipolarophiles with Bestmann-Ohira reagent. The reaction offers a convenient route for the synthesis of regioisomerically pure 3,5-disubstituted or 3,4,5-trisubstituted pyrazoles in
- Pramanik, Mukund M.D.,Kant, Ruchir,Rastogi, Namrata
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p. 5214 - 5220
(2014/07/08)
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- Synthesis of 3-carbonyl pyrazole-5-phosphonates via 1,3-dipolar cycloaddition of Bestmann-Ohira reagent with ynones
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The present work explores the hitherto unexplored reactivity of ynones as dipolarophiles with Bestmann-Ohira reagent. The reaction offers a convenient route for the synthesis of regioisomerically pure 3,5-disubstituted or 3,4,5-trisubstituted pyrazoles in
- Pramanik, Mukund M.D.,Kant, Ruchir,Rastogi, Namrata
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p. 5214 - 5220
(2014/12/10)
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- Highly efficient Cu(I)-catalyzed oxidation of alcohols to ketones and aldehydes with diaziridinone
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A novel and efficient Cu(I)-catalyzed oxidation of alcohols has been achieved with di-tert-butyldiaziridinone as the oxidant under mild conditions. A wide variety of primary and secondary alcohols with various functional groups can be oxidized to aldehydes and ketones in high yields. The reaction proceeds under neutral conditions making it compatible with acid- or base-sensitive substrates, and it is amenable to gram scale.
- Zhu, Yingguang,Zhao, Baoguo,Shi, Yian
-
supporting information
p. 992 - 995
(2013/04/10)
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- Oxidation of propargylic alcohols with a 2-quinoxalinol salen copper(II) complex and tert-butyl hydroperoxide
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The copper(II) complex of 2-quinoxalinol salen (salqu) is an efficient catalyst for the selective oxidation of propargylic alcohols to yield the corresponding α,β-acetylenic carbonyl compounds when used in combination with the oxidant tert-butyl hydroperoxide (TBHP). Excellent yields (up to 99 %) are achieved for a variety of propargylic alcohols within 1 h of reaction time. The (salqu)copper(II) complex with TBHP can be used with propargylic alcohols that contain alkyl groups in the α-position, which can be difficult to oxidize selectively with other commonly available methods. By using this catalytic protocol, excellent selectivity was also achieved for the oxidation of propargylic alcohols over that of isolated hydroxy groups, triple bonds, or propargylic methylene groups. The 2-quinoxalinol salen copper(II) complex is an efficient catalyst when used with tert-butyl hydroperoxide for the oxidation of propargylic alcohols to yield the corresponding carbonyl compounds. This catalytic system provides excellent selectivity for the reaction with propargylic alcohols, and high yields (up to 99 %) are achieved within 1 h and with 1 mol-% of catalyst loading. Copyright
- Weerasiri, Kushan C.,Gorden, Anne E. V.
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p. 1546 - 1550
(2013/04/10)
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- An efficient copper-catalysed pyrrole synthesis
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Copper-catalysed cyclisations of β-hydroxyhomopropargylic sulfonamides can be carried out using copper(II) acetate in hot toluene to provide generally excellent yields of the corresponding pyrroles. ARKAT-USA, Inc.
- Dunford, Damian G.,Knight, David W.,Wheeler, Robert C.
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p. 253 - 273
(2013/01/16)
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- Double duty for cyanogen bromide in a cascade synthesis of cyanoepoxides
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An unprecedented reaction mode of cyanogen bromide has been discovered. Under basic conditions, cyanogen bromide acts as an equivalent of both Br + and CN- to convert enolizable ketones into the corresponding cyanoepoxides in good yields. This unique reaction mode provides new, one-pot access to densely substituted cyanoepoxides from easily available ketones (see scheme). Copyright
- Li, Zhou,Gevorgyan, Vladimir
-
supporting information; experimental part
p. 2808 - 2810
(2011/05/05)
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- Mild and expedient asymmetric reductions of α,β-unsaturated alkenyl and alkynyl ketones by TarB-NO2 and mechanistic investigations of ketone reduction
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A facile and mild reduction procedure is reported for the preparation of chiral allylic and propargyl alcohols in high enantiomeric purity. Under optimized conditions, alkynyl and alkenyl ketones were reduced by TarB-NO 2 and NaBH4 at 25 °C in 1 h to produce chiral propargyl and allylic alcohols with enantiomeric excesses and yields up to 99%. In the case of α,β-unsaturated alkenyl ketones, α-substituted cycloalkenones were reduced with up to 99% ee, while more substituted and acyclic derivatives exhibited lower induction. For α,β-ynones, it was found that highly branched aliphatic ynones were reduced with optimal induction up to 90% ee, while reduction of aromatic and linear aliphatic derivatives resulted in more modest enantioselectivity. Using the (l)-TarB-NO2 reagent derived from (l)-tartaric acid, we routinely obtained highly enantioenriched chiral allylic and propargyl alcohols with (R) configuration. Since previous models and a reduction of a saturated analogue predicted propargyl products of (S) configuration, a series of new mechanistic studies were conducted to determine the likely orientation of aromatic, alkenyl, and alkynyl ketones in the transition state.
- Eagon, Scott,Delieto, Cassandra,McDonald, William J.,Haddenham, Dustin,Saavedra, Jaime,Kim, Jinsoo,Singaram, Bakthan
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experimental part
p. 7717 - 7725
(2011/01/05)
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- Highly-efficient and recyclable nanosized MCM-41 anchored palladium bipyridyl complex-catalyzed coupling of acyl chlorides and terminal alkynes for the formation of ynones
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A highly-efficient and practical method for the formation of ynones from a variety of acyl chlorides and terminal alkynes catalyzed by a nanosized MCM-41 anchored palladium bipyridyl complex is described herein. Aroyl, heteroaroyl, and alkyl acyl chlorides were easily coupled with terminal alkynes, giving good to high isolated yields in the presence of a very low catalyst loading (0.002-0.1 mol % Pd) in Et3N or diisopropylethylamine at 50 °C. Furthermore, the reaction scale was up to 150 mmol for a single batch reaction, providing the potential for practically synthetic application. After centrifugation, the supported catalyst was able to be recycled and reused several times with only a slight decrease in activity.
- Chen, Jun-You,Lin, Tze-Chiao,Chen, Szu-Chien,Chen, Ai-Jan,Mou, Chung-Yuan,Tsai, Fu-Yu
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experimental part
p. 10134 - 10141
(2010/02/28)
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- SUBSTITUTED PYRAZOLO [1,5-α] PYRIDINE COMPOUNDS AND THEIR METHODS OF USE
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The present invention is directed to substituted pyrazolo[l,5-α]pyridines and related methods for their synthesis and use.
- -
-
Page/Page column 46
(2010/11/29)
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- Trifluoromethyl 1-radical-mediated carbonylation of alkanes leading to ethynyl ketones
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The carbonylation of alkanes 1 under radical-reaction conditions was examined by using ethynyl triflone A as the unimolecular chain-transfer (UMCT) reagent. Good to moderate yields of ethynyl ketones 2 were prepared by means of this three-component coupli
- Uenoyama, Yoshitaka,Fukuyama, Takahide,Morimoto, Keisuke,Nobuta, Osaniu,Nagai, Hidefumi,Ryu, Ilhyong
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p. 2483 - 2494
(2007/10/03)
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- Room temperature palladium catalysed coupling of acyl chlorides with terminal alkynes
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Conditions are reported for the facile, high-yielding coupling of acyl chlorides with terminal alkynes in a reaction involving palladium and copper iodide; the reaction is tolerant of a wide variety of acyl chlorides and terminal alkynes and provides a co
- Cox, Russell J.,Ritson, Dougal J.,Dane, Thomas A.,Berge, John,Charmant, Jonathan P. H.,Kantacha, Anob
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p. 1037 - 1039
(2007/10/03)
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- Chemo- and regioselective cyclohydrocarbonylation of α-keto alkynes catalyzed by a zwitterionic rhodium complex and triphenyl phosphite
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α-Keto alkynes react with CO and H2 in the presence of catalytic quantities of the zwitterionic rhodium complex (η6-C6H5BPh3)- Rh+(1,5-COD) and triphenyl phosphite affording eith
- Van den Hoven,El Ali,Alper
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p. 4131 - 4137
(2007/10/03)
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- Stereoselective Synthesis of Highly Functionalized Trisubstituted Olefins via the Aldol Reaction of Allenoxyborinates with Carbonyl Compounds
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Allenoxyborinates, generated via the reaction of dicyclohexylborane with α,β-acetylenic ketones, react in situ with excess starting ketone to afford stereodefined, functionalized, trisubstituted olefins in good yields. The allenoxyborinates, (RCH=C=C(R′)OB(c-C6H11)2, can also be trapped by aldehydes and ketones when R′ is a tert-butyl group.
- Yu, Su,Li, Nan-Sheng,Kabalka, George W.
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p. 5822 - 5825
(2007/10/03)
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- Studies on copper(I) catalysed cross-coupling reactions: A convenient and facile method for the synthesis of diversely substituted α,β-acetylenic ketones
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Terminal alkynes reacted with acid chlorides in the presence of cuprous iodide as a catalyst in Et3N at room temperature yielding a number of α, β-acetylenic ketones in good to excellent yields.
- Chowdhury, Chinmay,Kundu, Nitya G.
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p. 7011 - 7016
(2007/10/03)
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- Alkynylation of aldehydic C-H bonds via reaction with acetylenic triflones.
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Reaction of aldehydes with acetylenic triflones affords acetylenic ketones and alkylated acetylenes via the intermediacy of acyl radicals, the product ratio being highly dependent upon aldehyde structure and reaction conditions.
- Gong, Jianchun,Fuchs
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p. 787 - 790
(2007/10/03)
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- Copper(I)-catalysed acylation of terminal alkynes
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A facile synthesis of conjugated acetylenic ketones is reported, involving Copper(I) catalysed acylation of terminal alkynes with acyl halides.
- Chowdhury, Chinmay,Kundu, Nitya G.
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p. 7323 - 7324
(2007/10/03)
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- Chiral Synthesis via Organoboranes. 34. Selective Reductions. 47. Asymmetric Reduction of Hindered α,β-Acetylenic Ketones with B-Chlorodiisopinocampheylborane to Propargylic Alcohols of Very High Enantiomeric Excess. Improved Workup Procedure for the Isol
-
The Midland reagent, Alpine-Borane (2a), is excellent for the asymmetric reduction of many acetylenic ketones but it fails with hindered derivatives.On the other hand, B-chlorodiisopinocampheylborane (DIP-Chloride, 4) reacts with hindered α,β-acetylenic k
- Ramachandran, P. Veeraraghavan,Teodorovic, Aleksandar V.,Rangaishenvi, Milind V.,Brown, Herbert C.
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p. 2379 - 2386
(2007/10/02)
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- Functional Group Hybrids. Reactivity of α'-Nucleofuge α,β-Unsaturated Ketones. 1. Reactions with Organocopper Reagents
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A series of α-nucleofuge α',β'-unsaturated ketones encompassing a variety of structural types and nucleofuges was prepared.Treatment of these compounds with lithium dimethylcuprate or methylcopper leads primarily to either reductive cleavage of the α-nucl
- Barbee, Thomas R.,Albizati, Kim F.
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p. 6764 - 6773
(2007/10/02)
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- SYNTHESIS OF ACETYLENIC KETONES
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A general preparative method of synthesis of acetylenic ketones was developed based on acylation of terminal acetylenes with acid chlorides in the presence of Cu(I) chloride.
- Zanina, A. S.,Shergina, I. S.,Sokolov, I. E.,Kotlyarevskii, I. L.
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p. 2307 - 2311
(2007/10/02)
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- A PPACTICAL CATALYTIC PROCEDURE FOR OXIDATION OF ALCOHOLS INTO ALDEHYDES OR KETONES WITH RuCl3/Water and Ca(OCl)2 or NaIO4
-
Ruthenium complexes catalyze the oxidation of alcohols to the corresponding ketones or aldehydes when Ca(OCl)2 or NaIO4 are used as oxygen donors in the presence of water (5 - 10 equiv.).The reactions take place at room temperature affording products in yields of 45 - 80percent.
- Genet, J. P.,Pons, D.,Juge, S.
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p. 1721 - 1726
(2007/10/02)
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- ACTIVATION OF CARBOXYLIC ACIDS AND ALCOHOLS BY INTRAMOLECULAR CYCLIZATION. ACYLATION OF TRIMETHYLSYSLILACETYLENES AND ALKYLATION OF AROMATIC COMPOUNDS
-
Carboxylic α-bromo-o-toluic anhydrides and alkyl α-bromo-toluates were activated by silver salts and used for the acylation of trimethylsilylacetylenes to acetylenic ketones and alkylation of aromatic compounds, respectively.
- Fukuoka, Satoshi,Nanri, Hiroshi,Katsuki, Tsutomu,Yamaguchi, Masaru
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p. 6205 - 6206
(2007/10/02)
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- SYNTHESIS IF ACETYLENIC KETONES FROM THIOL ESTERS AND 1-ALKYNYLTRIMETHYLSILANES
-
In the presence of silver tetrafluoroborate, S-ethyl carbothioates reacted with 1-alkynyltrimethylsilanes to give the corresponding acetylenic ketones in good yields.
- Kawanami, Yasuhiro,Katsuki, Tsutomu,Yamaguchi, Masaru
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p. 5131 - 5132
(2007/10/02)
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- Palladium-Catalyzed Reactions of Acyl Chlorides with (1-Alkynyl)tributylstannanes. A Convenient Synthesis for 1-Alkynyl Ketones
-
Acyl chlorides couple with (1-alkynyl)tributylstannanes in the presence of catalytic amounts of palladium(II) or palladium(0) complexes to produce 1-alkynyl ketones in respectable yields.The couplings of isobutyryl, acetyl, benzoyl, and p-nitrobenzoyl chlorides with phenylethynyl-, (trimethylsilyl)ethynyl-, (carbomethoxy)ethynyl-, -1-propynyl>-, and (3,3-diethoxy-1-propynyl)tributylstannanes were investigated in the presence of tetrakis(triphenylphosphine)palladium(O), benzylchlorobis(triphenylphosphine)palladium(II), dichlorobis(triphenylphosphine)palladium(II), or phenyliodobis(triphenylphosphine)palladium(II).The reactions are highly selective in that only the alkynyl groups are transferred from the stannane.
- Logue, Marshall W.,Teng, Kelly
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p. 2549 - 2553
(2007/10/02)
-