- Optimized synthesis of 7-azaindazole by a diels-alder cascade and associated process safety
-
Although pyrimidines are not among the most reactive partners in intramolecular inverse-electron-demand [4πs + 2πs] reactions with alkynes, they can be activated under mild and practical conditions, leading to fused nitrogen-containing heterocycles. We report an optimized synthesis of a 5-iodo-7-azaindazole by a one-pot Diels-Alder cascade that starts from a pyrimidine substituted at the 2-position by an (alkynyl)hydrazone. The safety of the process and the environmental impact were thoroughly evaluated. Eventually, a selection of cross-coupling reactions of 17 were studied and found to allow the introduction of carbon- and nitrogen-based nucleophiles at the 5-position in good to excellent yields.
- Bailly, Corinne,Bizet, Vincent,Blanchard, Nicolas,Brach, Nicolas,Gallou, Fabrice,Hoehn, Pascale,Lanz, Marian,Le Fouler, Vincent,Parmentier, Michael
-
-
Read Online
- Mechanism of acylation of lithium phenylacetylide with a Weinreb amide
-
Additions of lithium phenylacetylide to a Weinreb amide are described. Dimeric lithium acetylide reacts via a monosolvated monomer-based transition structure. The robust tetrahedral intermediate forms sequentially a C 1 2:2 mixed tetramer with
- Qu, Bo,Collum, David B.
-
-
Read Online
- Indium-mediated formation of propargyl ketones from aldehydes or acyl chlorides
-
Propargyl ketones were prepared from aldehydes via an indium-mediated alkynylation reaction followed by an indium-mediated Oppenauer oxidation. They were also obtained via an indium-mediated alkynylation of the relevant acyl chlorides.
- Augé, Jacques,Lubin-Germain, Nadège,Seghrouchni, Latifa
-
-
Read Online
- Trifluoromethyl 1-radical-mediated carbonylation of alkanes leading to ethynyl ketones
-
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
-
-
Read Online
- Ynonylation of Acyl Radicals by Electroinduced Homolysis of 4-Acyl-1,4-dihydropyridines
-
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
-
p. 4960 - 4965
(2021/07/20)
-
- Synthesis of Isoselenazoles and Isothiazoles from Demethoxylative Cycloaddition of Alkynyl Oxime Ethers
-
A general method for the synthesis of isoselenazoles and isothiazoles has been developed by the base-promoted demethoxylative cycloaddition of alkynyl oxime ethers using the cheap and inactive Se powder and Na2S as selenium and sulfur sources. This transformation features the direct construction of N-, Se-, and S-containing heterocycles through the formation of N-Se/S and C-Se/S bonds in one-pot reactions with excellent functional group tolerance.
- Zhang, Zhu-Zhu,Chen, Rong,Zhang, Xiao-Hong,Zhang, Xing-Guo
-
p. 632 - 642
(2020/12/22)
-
- Synthesis of 2-isoxazolyl-2,3-dihydrobenzofuransviapalladium-catalyzed cascade cyclization of alkenyl ethers
-
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
-
supporting information
p. 4799 - 4802
(2021/05/25)
-
- Bifunctional Borane Catalysis of a Hydride Transfer/Enantioselective [2+2] Cycloaddition Cascade
-
Herein, we present a mild and efficient method for synthesizing enantioenriched tetrahydroquinoline-fused cyclobutenes through a cascade reaction between 1,2-dihydroquinolines and alkynones with catalysis by chiral spiro-bicyclic bisboranes. The bisborane
- Zhang, Ming,Wang, Xiao-Chen
-
supporting information
p. 17185 - 17190
(2021/07/06)
-
- Methylation Alkynylation of Terminal Alkenes via 1,2-Alkynyl Migration Using Dicumyl Peroxide as the Methyl Source
-
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
-
p. 4700 - 4708
(2021/08/31)
-
- Selective Thiocyanation and Aromatic Amination to Achieve Organized Annulation of Enaminone with Thiocyanate
-
A tandem insertion of thiocyanate to enamine was performed for the regioselective synthesis of multisubstituted benzoimidazo[2,1-b]thiazoles. This method was shown to be effective in addressing the issue of isomerization encountered in common strategies. With a change made to the leading group on the aniline fragment of enamine, the reaction achieved different transformations, thus enabling multisubstituted benzo[4,5]imidazo[2,1-b]thiazoles and thiazoles in satisfactory yields.
- Feng, Xukai,Leng, Xin,Li, Jianli,Li, Yao,Liu, Hua,Liu, Lang,Liu, Ping,She, Mengyao,Zhang, Jun,Zhang, Shengyong,Zheng, Tingting
-
supporting information
p. 8396 - 8401
(2021/11/17)
-
- General Synthesis of α-Alkyl Ynones from Morpholine Amides and 1-Copper(I) Alkynes Promoted by Triflic Anhydride
-
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
-
p. 8296 - 8301
(2020/11/03)
-
- Copper-catalyzed method for preparing aldehyde or ketone compound by oxidizing alcohol with oxygen as oxidizing agent and application
-
The invention discloses a copper-catalyzed method for preparing an aldehyde or ketone compound by oxidizing alcohol with oxygen as an oxidizing agent. Reaction is performed in an organic solvent for 4-48 hours at room temperature by using copper salt and nitroxide free radicals as catalysts and oxygen or air as an oxidizing agent to efficiently oxidize an alcohol compound into the corresponding aldehyde or ketone compound. The method is simple to operate, free of chlorides corrosive to equipment, available in raw materials and reagents, mild in reaction conditions, wide in substrate universality, good in functional group compatibility, convenient in separation and purification, environmentally friendly in the whole process and free of pollution, and is a method suitable for industrial production.
- -
-
Paragraph 0028-0030; 0118-0123
(2020/08/18)
-
- Practical synthesis of α,β-Alkynyl ketones by oxidative alkynylation of aldehydes with hypervalent alkynyliodine reagents
-
A practical, metal-free carbonyl C(sp2)H oxidative alkynylation of aldehydes with hypervalent alkynyliodine reagents without the use of any catalysts is described for the synthesis of various α,β-alkynyl ketones. Here, two different methods have been developed where limiting reagents or substrates can be switched, and adopted according to the valuableness of aldehyde substrates or hypervalent alkynyliodine reagents. These reactions proceed with a broad substrate scope and high functional-group compatibility.
- Tsuzuki, Saori,Sakamoto, Ryu,Maruoka, Keiji
-
supporting information
p. 633 - 636
(2020/10/08)
-
- Activating Pyrimidines by Pre-distortion for the General Synthesis of 7-Aza-indazoles from 2-Hydrazonylpyrimidines via Intramolecular Diels-Alder Reactions
-
Pyrimidines are almost unreactive partners in Diels-Alder cycloadditions with alkenes and alkynes, and only reactions under drastic conditions have previously been reported. We describe how 2-hydrazonylpyrimidines, easily obtained in two steps from commercially available 2-halopyrimidines, can be exceptionally activated by trifluoroacetylation. This allows a Diels-Alder cycloaddition under very mild reaction conditions, leading to a large diversity of aza-indazoles, a ubiquitous scaffold in medicinal chemistry. This reaction is general and scalable and has an excellent functional group tolerance. A straightforward synthesis of a key intermediate of Bayer's Vericiguat illustrates the potential of this cycloaddition strategy. Quantum mechanical calculations show how the simple N-trifluoroacetylation of 2-hydrazonylpyrimidines distorts the substrate into a transition-state-like geometry that readily undergoes the intramolecular Diels-Alder cycloaddition.
- Le Fouler, Vincent,Chen, Yu,Gandon, Vincent,Bizet, Vincent,Salomé, Christophe,Fessard, Thomas,Liu, Fang,Houk,Blanchard, Nicolas
-
supporting information
p. 15901 - 15909
(2019/10/22)
-
- Metal-Free Promoted CF2/CF3-Difunctionalization of Unactivated Alkenes
-
An operationally simple radical difluoroalkylation/trifluoromethylation and alkynylation of unactivated alkenes under mild conditions has been developed. Through this protocol, a series of CF2/CF3- substituted linear alkynyl ketones
- Li, Ming,Zhu, Xin-Yu,Qiu, Yi-Feng,Han, Ya-Ping,Xia, Yu,Wang, Cui-Tian,Li, Xue-Song,Wei, Wan-Xu,Liang, Yong-Min
-
supporting information
p. 2945 - 2950
(2019/04/27)
-
- Palladium-Catalyzed Cascade Annulation/Allylation of Alkynyl Oxime Ethers with Allyl Halides: Rapid Access to Fully Substituted Isoxazoles
-
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
-
p. 11958 - 11970
(2019/10/11)
-
- One-pot regioselective synthesis of substituted pyrazoles and isoxazoles in PEG-400/water medium by Cu-free nano-Pd catalyzed sequential acyl Sonogashira coupling-intramolecular cyclization
-
Catalyst efficacy of in situ generated Pd-nanoparticles (PdNPs) in the regioselective one-pot synthesis of 3,5-di & 3,4,5-trisubstituted pyrazoles and 3,5-disubstituted isoxazoles in environmentally benign PEG-400/H2O medium, which involves the sequential (i) Cu-free acyl-Sonogashira coupling (ASC) and (ii) intramolecular ynone-amine cyclization under PTC conditions was described. The results of controlled experiments support the operation of two sequential catalytic cycles (ASC/cyclization) and achievement of complementary/opposite regioselectivity via ynone-bound palladium in a one-pot approach. Moreover, the in situ PdNPs recovered after the first catalytic cycle of the one-pot reaction sequence have been reused again five times successively. Besides, prior to the above studies, the efficacy of some common Pd-N-heterocyclic carbene (Pd-NHC) complexes in catalyzing the same one-pot two-step reaction sequence (Cu-free ASC/cyclization) both in water and organic solvents was also optimized. In situ generation of PdNPs from above Pd-NHCs in water was also identified, but they are not reusable due to their large size distribution.
- Thirukovela, Narasimha Swamy,Balaboina, Ramesh,Botla, Vinayak,Vadde, Ravinder,Jonnalagadda, Sreekantha Babu,Vasam, Chandra Sekhar
-
p. 6471 - 6481
(2019/11/20)
-
- An easy access towards quinazolines via an improved protocol for ynones
-
A simple and convenient method has been developed to accomplish Pt/2,2'-bipyridyl catalyzed acyl Sonagashira coupling for the efficient synthesis of ynones. The reaction display significant tolerance to various functional groups and the methodology has be
- Ghosh, Subhadeep,Das, Asish R.
-
p. 1249 - 1258
(2020/06/27)
-
- Phosphine-mediated partial reduction of alkynes to form both (E)- and (Z)-alkenes
-
A mild, phosphine-mediated partial reduction of alkynyl carbonyls to the corresponding alkenes was developed. Tuning of the reaction conditions led to either the (E)- or (Z)-diastereomer with high selectivity. A range of alkynyl esters, amides, and ketones were reduced to form alkenes in good to high yields and with excellent functional group tolerance.
- Pierce, Brett M.,Simpson, Brittany F.,Ferguson, Kane H.,Whittaker, Rachel E.
-
supporting information
p. 6659 - 6662
(2018/09/29)
-
- Enolizable β-Fluoroenones: Synthesis and Asymmetric 1,2-Reduction
-
The hydrofluorination of enolizable ynones with AgF in t-BuOH/DMF is reported. The formation of furans as side products can be suppressed using 2,2′-biphenol. The corresponding β-fluoroenones were obtained with good Z-selectivity. A variety of functional groups are tolerated. β-Fluoroenones are vinylogous acid fluorides whose hydrolysis to vinylogous acids can be avoided under the reported reaction conditions. The asymmetric 1,2-reduction of β-fluoroenones to 3-fluoroallylic alcohols is possible with pinacolborane and a Ni(0) catalyst prepared from a pyrimidyloxazoline ligand.
- Zygalski, Lukas,Middel, Christoph,Harms, Klaus,Koert, Ulrich
-
p. 5071 - 5074
(2018/08/24)
-
- Base-Promoted Tandem Reaction towards Conjugated Dienone or Chromone Derivatives with a Cyano Group: Insertion of Alkynes into C–C σ-Bonds of 3-Oxopropanenitriles
-
Base-promoted insertion reactions of alkynes into the C–C σ-bonds of α-cyano ketones were established to construct highly functionalized conjugated olefins or chromone derivatives via transition metal-free tandem reactions. These reactions are initialized through the nucleophilic attack of α-cyano ketones to alkynones followed by intramolecular nucleophilic addition/ring-opening to furnish the cyano-containing alkenes. In the cases of alkynones bearing an ortho-halide-substituted aryl ring, a further C–O bond coupling reaction occurs to afford chromone derivatives in good to high yields. Various alkynones bearing alkyl or aryl substituents were compatible in the reaction. This reaction has the potential to become a general synthetic protocol for the preparation of cyano-substituted olefins and chromones due to the abundance of easily accessible starting materials possessing diverse substituent groups. (Figure presented.).
- Yao, Qiyi,Kong, Lingkai,Zhang, Fangfang,Tao, Xianghua,Li, Yanzhong
-
supporting information
p. 3079 - 3084
(2017/09/13)
-
- Alkynylation of Csp2 (O)–H Bonds Enabled by Photoredox-Mediated Hydrogen-Atom Transfer
-
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
-
p. 14723 - 14726
(2017/10/18)
-
- A highly efficient heterogeneous palladium-catalyzed cascade three-component reaction of acid chlorides, terminal alkynes and hydrazines leading to pyrazoles
-
In the presence of 0.5 mol% of 3-(2-aminoethylamino)propyl-functionalized MCM-41-immobilized palladium(II) complex [MCM-41-2N-Pd(OAc)2] and 1.0 mol% of CuI, acid chlorides were coupled with terminal alkynes in Et3N at 50 °C to give α,β-unsaturated ynones, which were converted in situ into pyrazoles by the cycloaddition of hydrazines at room temperature with acetonitrile as cosolvent. The cascade reactions generated a variety of pyrazole derivatives in moderate to good yields, and this heterogeneous palladium catalyst exhibited higher catalytic activity than PdCl2(PPh3)2 and could be recovered and reused for at least 10 consecutive trials without any decreases in activity.
- Chen, Qiurong,Yao, Fang,Yin, Lin,Cai, Mingzhong
-
p. 108 - 113
(2016/01/15)
-
- Synthesis of Iron Oxide Palladium Nanoparticles and Their Catalytic Applications for Direct Coupling of Acyl Chlorides with Alkynes
-
A new, magnetic, silica-based, palladium nanocatalyst has been synthesized and employed for the first time in the direct coupling of acyl chlorides with terminal alkynes to prepare a variety of ynones. The synthesized nanocomposite is an excellent heterog
- Sharma, Rakesh K.,Yadav, Manavi,Gaur, Rashmi,Gupta, Radhika,Adholeya, Alok,Gawande, Manoj B.
-
p. 1312 - 1319
(2016/12/09)
-
- Decarboxylative Alkynylation and Carbonylative Alkynylation of Carboxylic Acids Enabled by Visible-Light Photoredox Catalysis
-
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)
-
- Direct synthesis of pyrazoles from esters using tert-butoxide-assisted C-(C=O) coupling
-
This paper describes the direct synthesis of pyrazoles from esters that comprises two sequential reactions: tert-butoxide-assisted C-C(=O) coupling reaction to yield β-ketonitrile or α,β-alkynone intermediates, and condensation by hydrazine addition. The method reported allows for easy control of the regioselectivity and structure of substituents at N-1, C-3, C-4 and/or C-5 positions.
- Kim, Bo Ram,Sung, Gi Hyeon,Ryu, Ki Eun,Lee, Sang-Gyeong,Yoon, Hyo Jae,Shin, Dong-Soo,Yoon, Yong-Jin
-
supporting information
p. 9201 - 9204
(2015/06/08)
-
- Synthesis of 3,5-disubstituted-1H-pyrazoles from acid chlorides, alkynes, and hydrazine in the presence of silica-supported-zinc bromide
-
An efficient one-pot palladium- And copper-free procedure has been developed for a convenient synthesis of 3,5-disubstituted-1H-pyrazoles from various acid chlorides, terminal alkynes and hydrazine by a coupling reaction and cyclocondensation sequence. Acid chlorides react with terminal alkynes in the presence of silica-supported-zinc bromide to give α,β-unsaturated ynones, and in situ conversion into pyrazoles by the hydrazine cyclocondensation.
- Keivanloo, Ali,Bakherad, Mohammad,Samangooei, Shahrzad
-
p. 484 - 486
(2015/11/03)
-
- Dual-immobilized copper catalyst: Carbon nitride-supported copper nanoparticles catalyzed oxidation of propargylic alcohols
-
Copper nanoparticles were supported and modified by carbon nitride, which was utilized as support and might work as a kind of immobilized N-donor ligand. The modified nanoparticle catalyst was evaluated with the oxidation of propargylic alcohols and showed highly catalytic efficiency as well as significant ligand or support effect in the reaction. The dual-immobilized nanoparticle catalyst could be recycled for 3 times at least without an obvious decrease in catalytic activities.
- Lv, Wei,Tian, Jing,Deng, Nan,Wang, Yan,Zhu, Xiaoshu,Yao, Xiaoquan
-
supporting information
p. 1312 - 1316
(2015/03/04)
-
- Selective oxidation of benzylic, allylic and propargylic alcohols using dirhodium(II) tetraamidinate as catalyst and aqueous tert-butyl hydroperoxide as oxidant
-
We show that the dirhodium(II) tetraamidinate complex Rh2(Msip)4 efficiently catalyzes the oxidation of activated secondary alcohols at only 0.1 mol% loading. In this approach, we oxidized various benzylic, allylic and propargylic alcohols to the corresponding carbonyl compounds under mild aqueous conditions using the inexpensive oxidant T-HYDRO (70 wt% aqueous tert-butyl hydroperoxide).
- Wusiman, Abudureheman,Lu, Chong-Dao
-
p. 254 - 258
(2015/03/30)
-
- Radical-induced metal-free alkynylation of aldehydes by direct C-H activation
-
A direct C(sp2)-H alkynylation of aldehyde C(O)-H bonds with hypervalent iodine alkynylation reagents provides ynones under metal-free conditions. In this method, 1-[(triisopropylsilyl)ethynyl]-1,2-benziodoxol-3(1H)-one (TIPS-EBX) constitutes a
- Liu, Xuesong,Yu, Linqian,Luo, Mupeng,Zhu, Jidong,Wei, Wanguo
-
supporting information
p. 8745 - 8749
(2015/06/08)
-
- Palladium- and solvent-free synthesis of ynones by copper(I)-catalyzed acylation of terminal alkynes with acyl chlorides under aerobic conditions
-
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
-
-
- Synthesis of 3-carbonyl pyrazole-5-phosphonates via 1,3-dipolar cycloaddition of Bestmann-Ohira reagent with ynones
-
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
-
p. 5214 - 5220
(2014/07/08)
-
- Synthesis of 3-carbonyl pyrazole-5-phosphonates via 1,3-dipolar cycloaddition of Bestmann-Ohira reagent with ynones
-
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
-
p. 5214 - 5220
(2014/12/10)
-
- One-pot three-component synthesis of 3,5-disubstituted isoxazoles by a coupling-cyclocondensation sequence
-
A convenient one-pot procedure for the synthesis of 3,5-disubstituted isoxazoles from acid chloride, terminal alkyne, and hydroxylamine hydrochloride catalyzed by Pd(PPh3)2Cl2/CuI has been developed. The coupling of acid c
- Liu, Hai-Ling,Geng, Zhu-Feng,Zhang, Si-Yu,Han, Jie
-
p. 1221 - 1227
(2014/05/20)
-
- Metal-free synthesis of ynones from acyl chlorides and potassium alkynyltrifluoroborate salts
-
A straightforward method for the preparation of ynones from acyl chlorides and potassium alkynyltrifluoroborate salts has been developed. The one-pot reaction proceeds rapidly in the presence of a Lewis acid without exclusion of air and moisture.
- Taylor, Cassandra,Bolshan, Yuri
-
supporting information
p. 488 - 491
(2014/04/03)
-
- Preparation of 3,5-disubstituted pyrazoles and isoxazoles from terminal alkynes, aldehydes, hydrazines, and hydroxylamine
-
The reaction of terminal alkynes with n-BuLi, and then with aldehydes, followed by the treatment with molecular iodine, and subsequently hydrazines or hydroxylamine provided the corresponding 3,5-disubstituted pyrazoles or isoxazoles in good yields with high regioselectivity, through the formations of propargyl secondary alkoxides and α-alkynyl ketones. The present reactions are one-pot preparation of 3,5-disubstituted pyrazoles from terminal alkynes, aldehydes, molecular iodine, and hydrazines, and 3,5-disubstituted isoxazoles from terminal alkynes, aldehydes, molecular iodine, and hydroxylamine.
- Harigae, Ryo,Moriyama, Katsuhiko,Togo, Hideo
-
p. 2049 - 2058
(2014/04/03)
-
- Palladium chloride-cryptand-22 complex: An efficient catalyst for the copper-, phosphorus-, and solvent-free synthesis of ynones
-
The palladium chloride-cryptand-22 complex was found to be an efficient catalyst for the copper-, phosphorus-, and solvent-free coupling reaction of terminal alkynes with different acyl chlorides in the presence of triethylamine as base, at room temperatu
- Navidi, Mozhgan,Movassagh, Barahman
-
p. 1363 - 1367
(2013/10/01)
-
- Highly efficient copper- and palladium-free one-pot coupling of alkynes with sodium carboxylate salts using cyanuric and magnesium chlorides
-
A facile and highly efficient copper- and palladium-free procedure for the one-pot synthesis of ynones via coupling of sodium carboxylate salts with alkynes is described. In this method, cross-coupling of terminal alkynes with a mixture of structurally diverse sodium carboxylate salts, cyanuric chloride and triethylamine in the presence of magnesium chloride furnishes the corresponding ynones in good to excellent yields at room temperature. Georg Thieme Verlag Stuttgart · New York.
- Soltanirad, Mohammad Navid,Behrouz, Somayeh
-
experimental part
p. 2562 - 2566
(2011/12/04)
-
- Silica-supported zinc bromide (ZnBr2/SiO2): A highly efficient heterogeneous catalyst for coupling acid chlorides with terminal alkynes
-
Silica-supported zinc bromide (ZnBr2/SiO2) is an efficient heterogeneous catalyst for the rapid synthesis of ynones by cross-coupling of acid chlorides with terminal alkynes in good to excellent yields under solvent-free conditions a
- Keivanloo, Ali,Bakherad, Mohammad,Bahramian, Bahram,Baratnia, Samaneh
-
experimental part
p. 1498 - 1502
(2011/05/16)
-
- Synthesis of ynones via recyclable polystyrene-supported palladium(0) complex catalyzed acylation of terminal alkynes with acyl chlorides under copper- and solvent-free conditions
-
Herein, a highly efficient method for the copper- and solvent-free coupling reaction of acyl chlorides and terminal alkynes catalyzed by 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone-functionalized polystyrene resin-supported Pd(0) complex is descri
- Bakherad, Mohammad,Keivanloo, Ali,Bahramian, Bahram,Jajarmi, Saeideh
-
experimental part
p. 311 - 314
(2011/04/12)
-
- Coupling reaction of acid chlorides with terminal alkynes catalyzed by diatomite-supported palladium(II) salophen complex
-
A highly-efficient method for the copper- and solvent-free coupling reaction of acid chlorides and terminal alkynes catalyzed by diatomite-supported palladium(II) salophen complex is described. Acid chlorides are easily coupled with terminal alkynes, givi
- Bakherad, Mohammad,Keivanloo, Ali,Bahramian, Bahram,Kalantar, Zahra,Ashrafi, Faezeh N.
-
experimental part
p. 364 - 367
(2012/05/31)
-
- Ligand-promoted, copper nanoparticles catalyzed oxidation of propargylic alcohols with TBHP or Air as Oxidant
-
A highly efficient oxidation of propargylic alcohols to ynones was catalyzed by copper nanoparticles (Cu Nps) with TBHP as an oxidant at room temperature. With bipyridine as the ligand, the reaction was accelerated significantly and led in good to excellent yields to a variety of propargylic alcohols. Furthermore, with Cu Nps as the catalyst, molecular oxygen in air could be utilized as oxidant effectively in the presence of bpy ligand. Georg Thieme Verlag Stuttgart - New York.
- Han, Chengyan,Yu, Min,Sun, Weijiang,Yao, Xiaoquan
-
experimental part
p. 2363 - 2368
(2011/10/30)
-
- Using Pd-salen complex as an efficient catalyst for the copper- and solvent-free coupling of acyl chlorides with terminal alkynes under aerobic conditions
-
The palladium-salen complex palladium(II) N,N′-bis{[5-(triphenylphosphonium)-methyl]salicylidene}-1,2-ethanediamine chloride was found to be a highly active catalyst for the copper- and solvent-free coupling reaction of terminal alkynes with different acy
- Bakherad, Mohammad,Amin, Amir Hossein,Keivanloo, Ali,Bahramian, Bahram,Raessi, Mersad
-
experimental part
p. 656 - 660
(2011/10/31)
-
- Synthesis of alkyl alkynyl ketones by Pd/light-induced three-component coupling reactions of iodoalkanes, CO, and 1-alkynes
-
Under photoirradiation conditions using xenon light, in the presence of a catalytic amount of PdCl2(PPh3)2 with triethylamine as a base, a three-component coupling reaction of iodoalkanes, carbon monoxide, and terminal alkynes proceeded to give alkyl alkynyl ketones in good yields.
- Fusano, Akira,Fukuyama, Takahide,Nishitani, Satoshi,Inouye, Takaya,Ryu, Ilhyong
-
supporting information; experimental part
p. 2410 - 2413
(2010/07/17)
-
- Highly-efficient and recyclable nanosized MCM-41 anchored palladium bipyridyl complex-catalyzed coupling of acyl chlorides and terminal alkynes for the formation of ynones
-
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
-
experimental part
p. 10134 - 10141
(2010/02/28)
-
- L-Proline-catalyzed synthesis of highly functionalized multisubstituted 1,4-dihydropyridines
-
Highly functionalized multisubstituted 1,4-dihydropyridines 5 have been concisely synthesized in moderate to good yields vial-proline-catalyzed one-pot multicomponent reactions (MCRs) of alkynoates or alkynones 1, amines 2, β-dicarbonyl compounds 3 and aldehydes 4 under mild conditions. The MCR process involves hydroamination/Knoevenagel condensation/Michael-type addition/intramolecular cyclization processes and leads to the formation of 1,4-dihydropyridines 5. The molecular structure of 5ckaa was confirmed by single-crystal X-ray diffraction. This method is energy saving and environmentally friendly, providing easy access to diverse multisubstituted polyfunctional 1,4-dihydropyridines. The Royal Society of Chemistry 2009.
- Jiang, Huanfeng,Mai, Ronghuan,Cao, Hua,Zhu, Qiuhua,Liu, Xiaohang
-
experimental part
p. 4943 - 4953
(2010/02/16)
-
- Copper-free Sonogashira coupling of acid chlorides with terminal alkynes in the presence of a reusable palladium catalyst: An improved synthesis of 3-iodochromenones (= 3-iodo-4H-1-benzopyran-4-ones)
-
Pd/C is used as an efficient catalyst for the copper-free Sonogashira coupling of acid chlorides and terminal alkynes to afford ynones in high yields (Tables 1 and 3). Cyclization of (2-methoxyaryl)-substituted ynones induced by I2/ammonium cer
- Likhar, Pravin R.,Subhas,Roy, Moumita,Roy, Sarabindu,Kantam, M. Lakshmi
-
experimental part
p. 259 - 264
(2009/02/07)
-
- One-pot three-component synthesis of pyrazoles through a tandem coupling-cyclocondensation sequence
-
An efficient and general one-pot procedure for the synthesis of pyrazoles from acid chlorides, terminal alkynes and hydrazines was described via a coupling and cyclocondensation sequence. Acid chlorides coupled with terminal alkynes to give α,β-unsaturated ynones, and in situ converted into pyrazoles by the cycloaddition of hydrazines. The desired pyrazoles were obtained with 15-85% isolated yields.
- Liu, Hai-Ling,Jiang, Huan-Feng,Zhang, Min,Yao, Wen-Juan,Zhu, Qiu-Hua,Tang, Zhou
-
p. 3805 - 3809
(2008/09/21)
-
- Cobalt(III) complex catalyzed aerobic oxidation of propargylic alcohols
-
An o-phenylenebis(N′-methyloxamidate) cobalt(III) complex works as an efficient catalyst for the oxidation of propargylic alcohols to the corresponding α,β-acetylenic carbonyl compounds, in the presence of pivalaldehyde, under an atmospheric pressure of m
- Blay, Gonzalo,Cardona, Luz,Fernandez, Isabel,Pedro, Jose R.
-
p. 3329 - 3332
(2008/09/21)
-
- Copper-, ligand- and solvent-free synthesis of ynones by coupling acid chlorides with terminal alkynes
-
A general and efficient copper-, ligand- and solvent-free synthesis of ynones by coupling of a wide range of acid chlorides with terminal alkynes catalyzed by palladium(II) acetate at room temperature is reported.
- Palimkar, Sanjay S.,Kumar, P. Harish,Jogdand, Nivrutti R.,Daniel, Thomas,Lahoti, Rajgopal J.,Srinivasan, Kumar V.
-
p. 5527 - 5530
(2007/10/03)
-