- A NOVEL METHOD FOR THE SYNTHESIS OF ALKYNYL KETONES - A REACTION OF ALKYNYL BORANES WITH AMIDES
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Alkynyl ketones are synthesized in high yields by the reaction of alkynyl boranes and amides under a mild reaction condition.
- Yamaguchi, Masahiko,Waseda, Toshie,Hirao, Ichiro
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- Synthesis of 2-isoxazolyl-2,3-dihydrobenzofuransviapalladium-catalyzed cascade cyclization of alkenyl ethers
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A novel palladium-catalyzed cascade cyclization reaction of alkenyl ethers with alkynyl oxime ethers for the construction of poly-heterocyclic scaffolds has been developed, in which the electron-rich alkene moiety functions as a three-atom unit, simultaneously dealing well with the coordination and regioselectivity of electron-rich olefins under metal catalysis. The strategy features excellent regio- and chemoselectivities as well as good functional group tolerance. Moreover, the newly formed 2-isoxazolyl-2,3-dihydrobenzofuran products can be further transformed to diverse complex heterocycles, demonstrating their potential applications in organic synthesis and medicinal chemistry.
- Zhou, Fei,Li, Can,Li, Meng,Jin, Yangbin,Jiang, Huanfeng,Zhang, Yingjun,Wu, Wanqing
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supporting information
p. 4799 - 4802
(2021/05/25)
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- Ynonylation of Acyl Radicals by Electroinduced Homolysis of 4-Acyl-1,4-dihydropyridines
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Herein we report the conversion of 4-Acyl-1,4-dihydropyridines (DHPs) into ynones under electrochemical conditions. The reaction proceeds via the homolysis of acyl-DHP under electron activation. The resulting acyl radicals react with hypervalent iodine(III) reagents to form the target ynones or ynamides in acceptable yields. This mild reaction condition allows wider functionality tolerance that includes halides, carboxylates, or alkenes. The synthetic utility of this methodology is further demonstrated by the late-stage modification of complex molecules.
- Luo, Xiaosheng,Wang, Ping
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p. 4960 - 4965
(2021/07/20)
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- Robust alkyl-bridged bis(N-heterocyclic carbene)palladium(II) complexes anchored on Merrifield's resin as active catalysts for the selective synthesis of flavones and alkynones
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Highly active and efficient propylene-bridged bis(N-heterocyclic carbene)palladium(II) complexes covalently anchored on Merrifield's resin were synthesized and characterized using various physical and spectroscopic techniques. The two anchored Pd(II) complexes consist of the system: Merrifield's resin-linker-bis(NHC)Pd(II), the linkers being benzyl and benzyl-O-(CH2)3 for (Pd-NHC1@M) and (Pd-NHC2@M), respectively. The short linker anchored bis-benzimidazolium ligand precursor (PBBI-1@M) was synthesized via direct carbon–nitrogen alkylation of a propylene-bridged bis(benzimidazole) (PBBI-1) by Merrifield's resin chlorobenzyl group. The longer linker anchored bis-benzimidazolium ligand precursor (PBBI-2@M) was obtained in a two-step reaction involving first alkylation of (PBBI-1) with 3-chloro-1-propanol followed by a nucleophilic substitution at Merrifield's resin chlorobenzyl group. Both supported ligand precursors (PBBI-1@M and PBBI-2@M) reacted with palladium acetate to produce the two heterogeneous catalysts (Pd-NHC1@M) and (Pd-NHC2@M). 13C NMR palladation shift of the benzimidazole N–C–N (C2) carbon was found very similar in both the liquid NMR spectra of the homogeneous complexes and the CP/MASS spectra of the corresponding covalently anchored complexes. The catalytic activity, stability, and the recycling ability of the supported catalysts have been investigated in the carbonylative Sonogashira coupling reactions of aryl iodides with aryl alkynes and alkyl alkynes and also in the cyclocarbonylative Sonogashira coupling reactions of aryl iodides with aryl alkynes via one pot reactions. The longer linker catalyst Pd-NHC2@M demonstrated excellent catalytic activity, stability, and very high recycling ability in the two carbonylative coupling reactions. These systems exhibit the hypothesized thermodynamic stability offered by the chelate effect in addition to the strong sigma donor ability of a bis(NHC) ligand system generating electron-rich palladium centers that favor the oxidative addition step of the aryl halide.
- Mansour, Waseem,Fettouhi, Mohammed,Saleem, Qasim,El Ali, Bassam
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- Metal-Free Oxidative [5+1] Cyclization of 1,5-Enynes for the Synthesis of Pyrazine 1-Oxide
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A chemo-selective nitrosylation of 1,5-enynes via a sequence of NO radical incorporation and intramolecular radical cyclization was reported. The formation of two C?N bonds and one C?O bond make this [5+1] cycloaddition reaction an efficient approach to synthesize pyrazine 1-oxides in moderate to good yields. Metal-free, short reaction time and mild conditions render this strategy more practical, eco-friendly and convenient. Synthetic utility of this protocol is highlighted by scaffolds diversification. (Figure presented.).
- Xia, Xiao-Feng,Zhao, Mingming,He, Wei,Zou, Lianghua,San, Xinxin,Wang, Dawei
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supporting information
p. 3621 - 3626
(2020/08/05)
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- Palladium(II) on 4 ? Molecular Sieves: A Simple and Reusable Catalyst for the Preparation of Ynones
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Abstract: Pd2+ on 4?? molecular sieves support has been prepared and investigated. The catalyst has successfully been used in the reaction of acyl chlorides and terminal alkynes yielding ynones. The catalyst can be reused without significant lo
- Juhász, Kinga,Hell, Zoltán
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p. 3335 - 3341
(2020/05/13)
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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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- Palladium-Catalyzed Cascade Annulation/Allylation of Alkynyl Oxime Ethers with Allyl Halides: Rapid Access to Fully Substituted Isoxazoles
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A novel and efficient approach for the synthesis of functionalized isoxazoles via palladium-catalyzed cascade annulation/allylation of alkynyl oxime ethers with allyl halides has been established. The present protocol exhibits mild reaction conditions, good functional group compatibility, and convenient operation. Moreover, scalability was performed and further decoration of the isoxazole product was achieved.
- Li, Can,Li, Jianxiao,Zhou, Fei,Li, Chaosheng,Wu, Wanqing
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p. 11958 - 11970
(2019/10/11)
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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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- Synthesis of novel 3-[(1-glycosyl-1H-1,2,3-triazol-4-yl)- methylamino]ket-2-en-1-ones
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[Figure not available: see fulltext.] Nine 3-[(1-β-D-ribofuranosyl- and 3-[(1-β-D-glucopyranosyl-1H-1,2,3-triazol-4-yl)methylamino]ket-2-en-1-ones have been synthesized by copper-catalyzed azide–alkyne cycloaddition (CuAAC) reaction between propargylamine
- Kumar, Banty,Maity, Jyotirmoy,Kumar, Amit,Khatri, Vinod,Shankar, Bhawani,Prasad, Ashok K.
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p. 362 - 368
(2018/06/04)
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- Phosphinito palladium(ii) complexes as catalysts for the synthesis of 1,3-enynes, aromatic alkynes and ynones
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An air-stable phosphinito palladium(ii) complex (Ph1-Phoxide) has been found to be an efficient catalyst in the formation of C-C bonds. The coupling of terminal alkynes formed gem-1,3-enynes as the only reaction products. Aromatic alkynes can be synthesized from the coupling of terminal alkynes and haloaromatic compounds (Sonogashira coupling). The phosphinito palladium(ii) complex also catalyses the coupling between acyl chlorides and terminal alkynes (Sonogashira coupling), furnishing ynones in excellent yields.
- Islas,Cárdenas,Gavi?o,García-Ríos,Lomas-Romero,Morales-Serna
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p. 9780 - 9789
(2017/02/15)
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- Control of the Regioselectivity in Cobalt- versus Ruthenium-Catalyzed Alder-ene Reaction of Unsymmetrical 1,3-Diynes
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The Alder-ene reaction of trialkylsilyl-substituted 1,3-butadiynes with terminal alkenes was investigated utilizing a cobalt-based catalyst, and the results were compared with Alder-ene rections catalyzed by the [CpRu(H3CCN)3]PF6 catalyst. Obviously, the two catalysts gave complementary results of yn-dienes differing in the site where the new carbon-carbon bond was formed. Of particular interest are observations concerning the double bond migration within the alkene component. While simple alkenes gave exclusively the E-configuration, the application of 3-buten-1-ol resulted in the corresponding Z-double bond, indicating that the hydroxyl group acts as donor coordinating to the cobalt center and thereby altering the reaction pathway.
- Weber, Sebastian M.,Hilt, Gerhard
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p. 564 - 567
(2017/02/10)
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- Ynones Merge Activation/Conjugate Addition of Chalcogenoborates ArE-Bpin (E=Se, S)
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The "pull-push" effect of the Bpin moiety in ArE-Bpin reagents (E=Se, S) is demonstrated by the Lewis acid interaction with the carbonyl group of ynones and the concomitant delivery of ArSe or ArS to the electron-deficient alkyne with impressive stereosel
- Civit, Marc G.,Sanz, Xavier,Vogels, Christopher M.,Bo, Carles,Westcott, Stephen A.,Fernández, Elena
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p. 3098 - 3103
(2015/11/03)
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- A Highly Active CuI/TMEDA Catalytic System for the Coupling Reaction of Acid Chlorides with Terminal Alkynes under Solvent-Free Conditions
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A highly efficient copper(I) iodide/N,N,N′,N′-tetramethylethylenediamine (CuI/TMEDA) catalytic system for the synthesis of ynones has been developed. A variety of terminal alkynes, including 4-iodophenylacetylene, were smoothly coupled with acid chlorides
- Yin, Weiyan,He, Haifeng,Zhang, Yani,Luo, Di,He, Hongwu
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p. 2617 - 2621
(2015/12/26)
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- Facile and efficient addition of terminal alkynes to benzotriazole esters: Synthesis of d-erythro-sphingosine using ynones as the key intermediate
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From the perspective of synthesis, ynones are compounds of considerable interest because of their occurrence in a wide variety of biologically active molecules and as key synthetic intermediates. In this context, a facile and highly efficient synthesis of ynones was developed based on the high reactivity of benzotriazole esters formed in situ. Lithium acetylides can alkylate various carboxylic acids in yields ranging from 60% to 92%. To determine whether our methodology is useful for synthesising complex and biologically relevant molecules, we synthesise d-erythro-sphingosine in four steps and with 33% overall yield from l-serine.
- Morales-Serna, José Antonio,Sauza, Alejandro,Padrón De Jesús, Gabriela,Gavi?o, Rubén,García De La Mora, Gustavo,Cárdenas, Jorge
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supporting information
p. 7111 - 7114
(2013/12/04)
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- Simple and general procedure for the synthesis of α,β-alkynyl ketones from nitriles using alkynyldimethylaluminum reagents
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A simple and efficient approach for the synthesis of α,β-alkynyl ketones from nitriles and alkynyldimethylaluminum reagents, derived from trimethylaluminum and alkynes, is described. This methodology provides access to a wide range of α,β-alkynyl ketones with aliphatic, aromatic, and heteroaromatic substituents in moderate to high yield (53-90%). In the cases of aryl-substituted nitriles, the product can also be obtained as α,β-alkynyl N-H ket-imines in high yield (88-93%). Georg Thieme Verlag Stuttgart, New York.
- Korbad, Balaji L.,Lee, Sang-Hyeup
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p. 1953 - 1958
(2013/09/24)
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- Palladium-catalyzed carbonylative coupling of aryl iodides and benzyl acetylenes to 3-alkylidenefuran-2-ones under mild conditions and its density functional theory modeling
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A general and efficient method for the palladium-catalyzed carbonylative coupling of aryl iodides to benzyl acetylenes has been developed. Various furanones have been prepared in excellent yields from their corresponding benzyl acetylenes at room temperat
- Wu, Xiao-Feng,Jiao, Haijun,Neumann, Helfried,Beller, Matthias
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p. 16177 - 16185
(2013/02/22)
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- Convenient and general palladium-catalyzed carbonylative sonogashira coupling of aryl amines
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Bar (alky)none: A general and efficient method for carbonylative Sonogashira coupling reactions of anilines to generate alkynones has been developed (see scheme; TFP=tri(2-furyl)phosphine). The reaction proceeds under mild conditions and no base is needed
- Wu, Xiao-Feng,Neumann, Helfried,Beller, Matthias
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experimental part
p. 11142 - 11146
(2012/02/03)
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- Palladium-catalyzed Sonogashira cross-coupling of organic tellurides with alkynes
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Alkyl aryl tellurides and a tellurol ester were used as coupling partners in Pd(0)-catalyzed Sonogashira reactions. Microwave-assisted reactions of alkyl aryl tellurides with alkynes in the presence of CuI and catalytic amounts of Pd(PPh3)4 produced alkynyl arenes. Similarly, a tellurol ester on reaction with alkynes afforded alkynyl phenyl ketones in the presence of CuI and a catalytic amount of Pd(PPh3)4 at room temperature.
- Kawaguchi, Shin-Ichi,Srivastava, Puneet,Engman, Lars
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experimental part
p. 4120 - 4122
(2011/09/19)
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- Pd-catalyzed carbonylative reactions of aryl iodides and alkynyl carboxylic acids via decarboxylative couplings
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Alkynyl carboxylic acids reacted with aryl iodides under a CO atmosphere in the presence of a palladium catalyst to produce α,β-alkynyl aryl ketones in good yields. The maximum turnover number was 16 800. The desired carbonylative coupling was formed from phenyl propiolic acid without any formation of a noncarbonylative coupling product in the absence of CuI. However, the reaction with alkyl-substituted alkynyl carboxylic acids required CuI as a cocatalyst for high yield.(Figure Presented)
- Park, Ahbyeol,Park, Kyungho,Kim, Yong,Lee, Sunwoo
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supporting information; experimental part
p. 944 - 947
(2011/04/24)
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- Synthesis of benzophenones from geminal biaryl ethenes using m-chloroperbenzoic acid
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The oxidation of geminal biaryl ethenes 3 and 1,3-enynes 5 using m-chloroperbenzoic acid in dichloromethane at room temperature presents a catalyst-free approach for the synthesis of functionalized benzophenones 4 and ynones 6, respectively.
- Singh, Fateh V.,Milagre, Humberto M.S.,Eberlin, Marcos N.,Stefani, Helio A.
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experimental part
p. 2312 - 2316
(2009/09/06)
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- Si-based benzylic 1,4-rearrangement/cyclization reaction
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(Chemical Equation Presented) The trans-selective hydrosilylation of ynones (1) yields ss-silylated enones (2) that undergo a benzylic 1,4-rearrangement/cyclization reaction in the presence of base, yielding 2,5-dihydro-1,2-oxasiloles (3).
- Trost, Barry M.,Bertogg, Andreas
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supporting information; experimental part
p. 511 - 513
(2009/07/10)
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- 3-Aroylindoles via copper-catalyzed cyclization of N-(2-iodoaryl)enaminones
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3-Aroylindoles have been prepared via copper-catalyzed cyclization of N-(2-iodoaryl)enaminones, readily available from 2-iodoanilines and α,β-ynones. The reaction tolerates a variety of useful functionalities including ether, keto, cyano, bromo, and chlor
- Bernini, Roberta,Cacchi, Sandro,Fabrizi, Giancarlo,Filisti, Eleonora,Sferrazza, Alessio
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body text
p. 1480 - 1484
(2009/10/17)
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- N-propargylic β-enaminones: Common intermediates for the synthesis of polysubstituted pyrroles and pyridines
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N-Propargylic β-enaminones have been used as common intermediates for the synthesis of polysubstituted pyrroles and pyridines. Best results have been obtained using DMSO as solvent. In the presence of Cs2CO3 N-propargylic β-enaminone
- Cacchi, Sandro,Fabrizi, Giancarlo,Filisti, Eleonora
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supporting information
p. 2629 - 2632
(2013/08/23)
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- A straightforward synthesis of Ynones by reaction of dimethylalkynylaluminum reagents with acid chlorides
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Alkynyldimethylaluminum reagents react with various aromatic and aliphatic acid chlorides in a fast and efficient way. This reaction provides a simple entry to numerous ynones, using readily available, inexpensive, and nontoxic metalating agent, and does not require any transition metal as a catalyst.
- Wang, Baomin,Bonin, Martine,Micouin, Laurent
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p. 6126 - 6128
(2007/10/03)
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- Polymer-supported selenol esters as useful acylating reagents. Application to α, β-acetylenic ketones synthesis
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Three novel polystyrene supported selenol esters were synthesized and used as acyl transfer agents to prepare α, β-acetylenic ketones by reaction with alkynylcoppers.
- Qian,Shao,Huang
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p. 1571 - 1572
(2007/10/03)
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- New synthetic applications of organotin compounds: Synthesis of stereodefined 2-iodo-2-alkenones, 2-substituted (E)-2-alkenones and 2-methyl-2-cycloalkenones
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Stereoisomeric mixtures of 3-iodo-3-nonen-2-one, 8a, 2-iodo-1-phenyl-2-octen-1-one, 8b, 2-iodo-1,3-diphenyl-2-propen-1-one, 8c, as well as (Z)-3-iodo-4-phenyl-3-buten-2-one, 8d, have been efficiently synthesized by a reaction sequence involving a Pd-catalyzed reaction between the corresponding 1-alkynyl ketones, 10, and Bu3SnH followed by iododestannylation. Stereomutation experiments carried out in the presence of daylight and using catalytic amounts of I2 showed that the Z stereoisomers of 8a, 8b and 8c, which could be separated by MPLC on silica gel from the corresponding E stereoisomers, as well as compound (Z)-8d were more stable than their E stereoisomers. Compounds 8a-d underwent Pd-catalyzed cross-coupling reactions with C6H5SnMe3, CH2=CH-SnBu3 and SnMe4 providing an efficient route to the corresponding 2-substituted 2-alkenones, 13. However, the Pd-catalyzed reaction between (Z)-8c and PhSnMe3 afforded a mixture of the expected cross-coupled product, (E)-13f with the compound derived from methyl transfer, (E)-13e. The couplings involving (Z)-8a, (Z)-8b, (Z)-8c and (Z)-8d proceeded with clean retention of stereochemistry, but the Pd-catalyzed reaction between (E)-8c and SnMe4 afforded a stereoisomeric mixture of 13e. On the contrary, the coupling between (E)/(Z)-8b and SnMe4 produced stereoisomerically pure (E)-13c. Two 2-iodo-2-cycloalkenones, i.e. compounds 18a and 18b, also reacted with SnMe4, in the presence of a Pd catalyst, to give the corresponding 2-methyl-2-cycloalkenones, 19a and 19b, respectively, in satisfactory yields. Compound 19b represents a very useful precursor to methylenomycin B, 9.
- Bellina, Fabio,Carpita, Adriano,Ciucci, Donatella,De Santis, Massimo,Rossi, Renzo
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p. 4677 - 4698
(2007/10/02)
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- PALLADIUM-CATALYZED ACYLATION OF ORGANOZINCS AND OTHER ORGANOMETALLICS AS A CONVENIENT ROUTE TO KETONES
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The reaction of organozincs with acyl chlorides catalyzed by palladium-phosphine complexes, e.g., Pd(PPh3)4, provides a highly general and convinient route to ketones.
- Negishi, Ei-ichi,Bagheri, Vahid,Chatterjee, Sugata,Luo, Fen-Tair,Miller, Joseph A.,Stoll, A. Timothy
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p. 5181 - 5184
(2007/10/02)
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