- Heptalene Synthesis by Addition of Aryl Acetylenes to Azulenes
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Abstract: Aryl acetylenes bearing electron-withdrawing groups have been found that canadd to azulenes and yield 1,2-substituted heptalenes. Theoretical studies of thereaction mechanism helped to design the candidate molecules that have then beentested in
- Briling, K. R.,Laikov, D. N.
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- Zeolitic imidazolate frameworks-67 (ZIF-67) supported PdCu nanoparticles for enhanced catalytic activity in Sonogashira-Hagihara and nitro group reduction under mild conditions
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A bimetallic PdCu supported on amine functionalized ZIF-67 is shown to be efficient catalyst in Sonogashira-Hagihara coupling reaction of aryl iodides at room temperature and aryl bromides at 40 oC. In addition, the catalyst is used in the reduction of 4-
- Gholinejad, Mohammad,Naghshbandi, Zhwan,Sansano, Jose M.
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- Rip It off: Nitro to Nitroso Reduction by Iron Half-Sandwich Complexes
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Activation of [FeCl(dppe)Cp] (1) by chloride abstraction with Na[BArX4] (X = F, [B(3,5-(CF3)2-C6H3)4]; X = Cl, [B(3,5-Cl2-C6H3)4]) permits reactions with a range of nitro aromatics, RC6H4NO2 (R = halogen, Me, OMe, NO2 or NMe2), to give the cationic iron nitroso complexes [Fe{N(O)-C6H4R}(dppe)Cp][BArX4]) ([3][BArX4]). Similar reactions of 1 and Na[BArX4] with [Fe(NCC6H4NO2)(dppe)Cp][BArX4] gave bimetallic [{Fe(dppe)Cp}2{μ-NCC6H4N(O)}][BArF4]2. However, reactions of 1 and Na[BArX4] with 4-nitrophenol gave the first example of the bench-stable iron half-sandwich phenolate complex [Fe(OC6H4NO2)(dppe)Cp]+ rather than NO2 activation. The formation of complexes [3]+ likely proceeds via the unusual blue bimetallic species [{Fe(dppe)Cp}2{μ,κ2O,O′-O2NAr}]2+. This compound undergoes N-O bond cleavage, resulting in [3]+ and a FeIV=O species, which reacts via an internal C-H activation of the dppe ligand to give [FeIII(κ3O,P,P′-P(2-O-C6H4)(Ph)-C2H4-PPh2)Cp]+. Complexes [3]+ are stable under ambient conditions, are readily purified by column chromatography and can be isolated in up to 50% yield, considering that 0.5 equiv of 1 is required as the oxygen acceptor.
- Korb, Marcus,Hosseini Ghazvini, Seyed Mohammad Bagher,Moggach, Stephen A.,Meunier, Jean-Fran?ois,Bousseksou, Azzedine,Low, Paul J.
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p. 4986 - 4995
(2021/04/06)
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- Copper-Catalyzed Cross-Nucleophile Coupling of β-Allenyl Silanes with Tertiary C-H Bonds: A Radical Approach to Branched 1,3-Dienes
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Described herein is a distinctive approach to branched 1,3-dienes through oxidative coupling of two nucleophilic substrates, β-allenyl silanes, and hydrocarbons appending latent functionality by copper catalysis. Notably, C(sp3)-H dienylation proceeded in a regiospecific manner, even in the presence of competitive C-H bonds that are capable of occurring hydrogen atom transfer process, such as those located at benzylic and other tertiary sites, or adjacent to an oxygen atom. Control experiments support the intermediacy of functionalized alkyl radicals.
- Shan, Qi-Chao,Hu, Lu-Min,Qin, Wei,Hu, Xu-Hong
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p. 6041 - 6045
(2021/08/03)
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- Transition-metal-free and facile synthesis of 3-alkynylpyrrole-2,4-dicarboxylates from methylene isocyanides and propiolaldehyde
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A transition-metal-free, facile and efficient method for the synthesis of 3-alkynylpyrrole-2,4-dicarboxylates from methylene isocyanides and propiolaldehyde with moderate to good yields has been developed. The direct transformation process and good tolerance of various substituents make it an alternative approach to previous protocols, and potential applications of these investigated compounds are expected with or without post-modifications.
- Chen, Xiaojuan,Fu, Liping,Huo, Xiaoli,Shao, Jiaan,Yu, Liya,Zeng, Linghui,Zhang, Chong,Zhang, Jiankang,Zhu, Huajian
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p. 16430 - 16433
(2021/10/01)
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- Chemo- And regioselective click reactions through nickel-catalyzed azide-alkyne cycloaddition
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Metal-catalyzed cycloaddition is an expeditious synthetic route to functionalized heterocyclic frameworks. However, achieving reactivity-controlled metal-catalyzed azide-alkyne cycloadditions from competing internal alkynes has been challenging. Herein, we report a nickel-catalyzed [3 + 2] cycloaddition of unsymmetrical alkynes with organic azides to afford functionalized 1,2,3-triazoles with excellent regio- and chemoselectivity control. Terminal alkynes and cyanoalkynes afford 1,5-disubstituted triazoles and 1,4,5-trisubstituted triazoles bearing a 4-cyano substituent, respectively. Thioalkynes and ynamides exhibit inverse regioselectivity compared with terminal alkynes and cyanoalkynes, affording 1,4,5-trisubstituted triazoles with 5-thiol and 5-amide substituents, respectively. Density functional theory calculations are performed for the elucidation of the reaction mechanism. The computed mechanism suggests that a nickellacyclopropene intermediate is generated by the oxidative addition of the alkyne substrate to the Ni(0)-Xantphos catalyst, and the subsequent C-N coupling of this intermediate with an azide is responsible for the chemo- and regioselectivity.
- Baek, Seung-Yeol,Baik, Mu-Hyun,Choe, Wonyoung,Hong, Sung You,Jeon, Ji Hwan,Jeong, Seo Yeong,Kim, Woo Gyum,Nam, Dongsik
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supporting information
p. 3374 - 3381
(2020/05/14)
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- HighlyZ-selective synthesis of 1,3-oxathiol-2-ylidenes and 4-methylene-oxazolidine-2-thionesviaatom-specific 5-exo-digcyclization of propargyl alcohol with isothiocyanate
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DBU mediated 5-exo-digcyclization of isothiocyanate and propargyl alcohol leading to valuable heterocyclic compounds has been accomplished. The different modes of nucleophilicity (eitherS-selective orN-selective) of isothiocyanates were found to depend on
- Antony Savarimuthu, S.,Augustine Thomas, S.,Bera, Mrinal K.,Gandhi, Thirumanavelan,Leo Prakash, D. G.
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p. 3552 - 3562
(2020/05/25)
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- Catalytic Access to Functionalized Allylic gem-Difluorides via Fluorinative Meyer–Schuster-Like Rearrangement
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An unprecedented approach for efficient synthesis of functionalized allylic gem-difluorides via catalytic fluorinative Meyer–Schuster-like rearrangement is disclosed. This transformation proceeded with readily accessible propargylic fluorides, and low-cost B–F reagents and electrophilic reagents by sulfide catalysis. A series of iodinated, brominated, and trifluoromethylthiolated allylic gem-difluorides that were difficult to access by other methods were facilely produced with a wide range of functional groups. Importantly, the obtained iodinated products could be incorporated into different drugs and natural products, and could be expediently converted into many other valuable gem-difluoroalkyl molecules as well. Mechanistic studies revealed that this reaction went through a regioselective fluorination of alkynes followed by a formal 1,3-fluorine migration under the assistance of the B–F reagents to give the desired products.
- An, Rui,Li, Huimin,Liao, Lihao,Wu, Jin-Ji,Xu, Yang,Zhao, Xiaodan
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supporting information
p. 11010 - 11019
(2020/05/18)
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- Pd(0) nanoparticles immobilized on multinitrogen functionalized halloysite for promoting Sonogashira reaction: studying the role of the number of surface nitrogens in catalytic performance
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Halloysite nanoclay, Hal, was amine-functionalized and subsequently reacted with 2,4,6-trichloro-1,3,5-triazine, TCT, and ethylenediamine, EDA, to provide multinitrogen containing functionality on the surface of Hal. The resulting surface-modified Hal, Ha
- Sadjadi, Samahe,Heravi, Majid M.,Masoumi, Baharak,Kazemi, Shaghayegh Sadat
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p. 119 - 134
(2019/01/30)
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- Pd@GO/Fe3O4/PAA/DCA: a novel magnetic heterogeneous catalyst for promoting the Sonogashira cross-coupling reaction
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A hybrid system involving graphene oxide (GO), magnetic oxide (Fe3O4), acrylamide and dicyandiamide was prepared via amine functionalization of GO/Fe3O4 by means of covalent bonding with acrylamide and subsequent reaction with dicyandiamide to provide a multinitrogen containing polymer on the surface of GO. This hybrid system was utilized as a heterogeneous catalyst support for immobilizing Pd nanoparticles to provide the hybrid, Pd@GO/Fe3O4/PAA/DCA. This nano-Pd composite was characterized using Fourier transform infrared, transmission electron microscopy, scanning electron microscopy, vibrating sample magnetometer, thermogravimetric analysis, X-ray diffraction, and ICP techniques and used for promoting Sonogashira cross-coupling under mild reaction conditions. This heterogeneous and magnetic catalyst was easily separated by external magnet and was reused in a model reaction, efficiently up to six times with slight loss of catalytic activity and Pd leaching, showing the suitability of GO/Fe3O4/PAA/DCA for embedding Pd nanoparticles. To check the effect of the number of surface nitrogens of the polymeric chain on the catalytic performance, the activity of the catalyst was compared with Pd@GO/Fe3O4/PAA; increased number of the surface nitrogens on the chain polymer leads to higher loading of Pd and lower the Pd leaching.
- Daraie, Mansoureh,Heravi, Majid M.,Kazemi, Shaghayegh Sadat
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p. 2279 - 2293
(2019/08/07)
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- Magnetic covalent hybrid of graphitic carbon nitride and graphene oxide as an efficient catalyst support for immobilization of Pd nanoparticles
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For the first time a magnetic carbon based hybrid catalyst, Pd@g-C3N4-Fe-GO, is prepared through covalent conjugation of magnetic graphitic carbon nitride and graphene oxide followed by incorporation of Pd nanoparticles. First, the formation of the catalyst was confirmed via XRD, TG, BET, TEM, FTIR, ICP and VSM analyses and then its catalytic activity for promoting Suzuki and Sonogashira coupling reactions under mild reaction condition was investigated. To elucidate whether hybridization of two carbon materials could improve the catalytic activity, the catalytic activity of the catalyst was compared with the control catalysts (Pd@g-C3N4 -GO, Pd@g-C3N4-Fe, Pd@ Fe-GO, Pd@g-C3N4, Pd@GO and the GO/g-C3N4 physical hybrid). Moreover, the role of magnetic nanoparticles in the catalytic performance was confirmed. Notably, the catalytic activities of the catalyst and the control sample prepared via physical hybridization of two carbon materials were compared to confirm the effect of covalent conjugation on the catalytic activity. Moreover, the study of the substituent effect of p-substituted phenyl iodides was considered by Hammett plot, which revealed a beneficial effect of electron-withdrawing side groups for the C–C coupling reaction. Finally, the recyclability of Pd@g-C3N4-Fe-GO as well as leaching of Pd and magnetic nanoparticles was studied.
- Sadjadi, Samahe,Malmir, Masoumeh,Heravi, Majid M.,Ghoreyshi Kahangi, Fatemeh
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- Synthesis of (: Z)-β-halo α,β-unsaturated carbonyl systems via the combination of halotrimethylsilane and tetrafluoroboric acid
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A convenient and broadly applicable method for the hydrohalogenation of ynones is described, by the combination of halotrimethylsilanes and tetrafluoroboric acid. Practically, one equivalent of HX (Br?nsted acid) and BF3 (Lewis acid) is smoothly generated, which activates the carbonyl compounds. Through this protocol, 42 examples of (Z)-β-halovinyl carbonyl compounds (Cl, Br and I) were obtained, in good yields and high stereoselectivity having 2-MeTHF as a solvent.
- Da Silva, Vitor A. F.,Da Silva, Gustavo P.,Matsuo, Bianca T.,Ali, Akbar,Davis, Rebecca L.,Zukerman-Schpector, Julio,Corrêa, Arlene G.,Paix?o, Márcio W.
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supporting information
p. 519 - 526
(2019/01/24)
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- Halloysite nanoclay decorated with 2-amino pyrimidine functionalized poly glycidyl methacrylate: An efficient support for the immobilization of Pd nanoparticles
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Taking advantage of the synergistic effects between polymer (P) and halloysite clay (Hal) as well as the capability of heteroatom-containing polymers for anchoring nanoparticles and suppressing their leaching, a novel support composed of Hal and 2-amino p
- Sadjadi, Samahe,Koohestani, Fatemeh,Bahri-Laleh, Naeimeh,Didehban, Khadijeh
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- Palladium-catalyzed Sonogashira coupling reactions in γ-valerolactone-based ionic liquids
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It was demonstrated that the γ-valerolactone-based ionic liquid, tetrabutylphosphonium 4-ethoxyvalerate as a partially bio-based solvent can be utilized as alternative reaction medium for copper- and auxiliary base-free Pd-catalyzed Sonogashira coupling reactions of aryl iodides and functionalized acetylenes under mild conditions. Twenty-two cross-coupling products were isolated with good to excellent yields (72–99%) and purity (>98%). These results represent an example which proves that biomass-derived safer solvents can be utilized efficiently in common, industrially important transformations exhibiting higher chemical and environmental efficiency.
- Orha, László,Tukacs, József M.,Kollár, László,Mika, László T.
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supporting information
p. 2907 - 2913
(2019/12/14)
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- Rhodium-Catalyzed 1,1-Hydroacylation of Thioacyl Carbenes with Alkynyl Aldehydes and Subsequent Cyclization
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A rhodium-catalyzed 1,1-hydroacylation of thioacyl carbenes with alkynyl and alkenyl aldehydes and subsequent 6-endo-trig/dig cyclization are realized, giving structurally diverse 4H-thiopyran-4-ones and 2,3-dihydro-4H-thiopyran-4-ones in moderate to good yields. The oxidative addition of Rh(I) to aldehydes is proposed to be the turnover-limiting step. Manipulations of estrones demonstrate the applications of our formal (3 + 3) transannulations in the structural modifications of natural products.
- Zhou, Bingnan,Wu, Qiuyue,Dong, Ziyang,Xu, Jiaxi,Yang, Zhanhui
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supporting information
p. 3594 - 3599
(2019/05/24)
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- Catalyst-Free Annulation of 2-Pyridylacetates and Ynals with Molecular Oxygen: An Access to 3-Acylated Indolizines
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A catalyst and additive-free annulation of 2-pyridylacetates and ynals under molecular oxygen was the first developed, affording 3-acylated indolizines in good to excellent yields. Molecular oxygen was used as the source of the carbonyl oxygen atom in indolizines. This approach was compatible with a wide range of functional groups, and especially it has been successfully extended to unsaturated double bonds and triple bonds, which were difficult to prepare by previous methods in a single step.
- Chen, Zhengwang,Liang, Pei,Ma, Xiaoyue,Luo, Haiqing,Xu, Guohai,Liu, Tanggao,Wen, Xiaowei,Zheng, Jing,Ye, Hui
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supporting information
p. 1630 - 1639
(2019/01/26)
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- Metal-free aminothiation of alkynes: Three-component tandem annulation toward indolizine thiones from 2-alkylpyridines, ynals, and elemental sulfur
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A metal-free three-component annulation reaction for the synthesis of indolizine thiones via tandem C-C/C-N/C-S bond formation was developed. Various 2-alkylpyridines with aromatic ynals and elemental sulfur proceeded smoothly under catalyst-free conditions, and the desired products were obtained in moderate to excellent yields.
- Chen, Zhengwang,Liang, Pei,Xu, Fan,Deng, Zhen,Long, Lipeng,Luo, Guotian,Ye, Min
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supporting information
p. 12639 - 12647
(2019/10/11)
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- Comparison between Conventional and Nonconventional Methods for the Synthesis of Some 2-Oxazolidinone Derivatives and Preliminary Investigation of Their Inhibitory Activity Against Certain Protein Kinases
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A series of propargyl and allyl carbamates were prepared directly from propargyl and allyl alcohols and phenyl or cyclohexyl isocyanate or indirectly by generating the isocyanates in situ from the corresponding Cbz-protected amines. The obtained carbamate
- Ziane,Mazari,Safer,Sad El Hachemi Amar,Ruchaud,Baratte,Bach
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p. 1061 - 1069
(2019/09/06)
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- Palladium-Catalyzed Nitrile-Assisted C(sp3)-Cl Bond Formation for Synthesis of Dichlorides
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A palladium-catalyzed coupling procedure of alkenes with alkynylnitriles has been demonstrated for the synthesis of dichlorides. The reaction is the first example of nitrile-assisted C(sp3)-Cl formation promoted by coordination of a cyano group with an alkylpalladium(II) complex. The construction of a five-membered cycle intermediate successfully inhibits the β-hydride abstraction, resulting in direct C-Cl bond reductive elimination of alkylpalladium(II) chloride.
- He, Dandan,Huang, Liangbin,Li, Jianxiao,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 8308 - 8311
(2019/10/16)
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- Metal-free hydroamination of alkynes: A mild and concise synthesis of thiazolo[3,2- a ]indoles and their cytotoxic activity
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A metal-free, mild and efficient method for the synthesis of thiazolo[3,2- a ]indoles has been developed starting from indoline-2-thiones. The reaction methodology involves first the formation of thermally labile 2-(prop-2-ynylthio)-1 H -indole intermedia
- Bhave, Vishakha S.,Hojo, Ryoga,Jha, Mukund,Rhodes, Steven,Short, Spencer
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supporting information
p. 4263 - 4270
(2019/11/13)
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- Bi(OTf)3 catalyzed synthesis of acyclic β-sulfanyl ketones via a tandem Meyer-Schuster rearrangement/conjugate addition reaction
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A new strategy to prepare acyclic β-carbonyl thioethers from propargyl alcohols and sulfur nucleophiles is reported. The investigation of the reaction substrates scope indicated that primary 3-aryl propargyl alcohols and thiols underwent the transformation smoothly. The reaction probably proceeded a Bi(OTf)3-catalyzed tandem Meyer-Schuster rearrangement of 3-aryl propargyl alcohol, followed by a thiol Michael conjugate addition of thiols to in situ generated α, β-unsaturated ketones. The method was 100% atom economic, high-yielding, and easy to handle, making it a valuable method for the construction of β-carbonyl sulfides.
- Wang, Yuan,Yin, Yan,Zhang, Qinglin,Pan, Wanyong,Guo, Huifeng,Pei, Keke
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supporting information
p. 2030 - 2034
(2019/07/03)
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- Efficient 1,3-Oxazolidin-2-one Synthesis through Heterogeneous PdII-Catalyzed Intramolecular Hydroamination of Propargylic Carbamates
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Herein, we present an operationally simple protocol for the cycloisomerization of propargylic carbamates in which a heterogeneous catalyst consisting of Pd species immobilized on amino-functionalized siliceous mesocellular foam (PdII-AmP-MCF) i
- Oschmann, Michael,Placais, Clotilde,Nagendiran, Anuja,B?ckvall, Jan-E.,Verho, Oscar
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supporting information
p. 6295 - 6299
(2019/05/08)
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- Palladium nanoparticles immobilized on cyclodextrin-decorated halloysite nanotubes: Efficient heterogeneous catalyst for promoting copper- and ligand-free Sonogashira reaction in water–ethanol mixture
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Combining the excellent features of halloysite nanoclay and cyclodextrin, a novel hybrid system was designed and synthesized based on covalent attachment of tosylated cyclodextrin to thiosemicarbazide-functionalized halloysite nanoclay and used for the im
- Sadjadi, Samahe
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- Nickel(II)-Catalyzed Asymmetric Propargyl [2,3] Wittig Rearrangement of Oxindole Derivatives: A Chiral Amplification Effect
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A highly enantioselective [2,3] Wittig rearrangement of oxindole derivatives was realized by using a chiral N,N′-dioxide/NiII complex as the catalyst under mild reaction conditions. A strong chiral amplification effect was observed, and allowed access to chiral 3-hydroxy 3-substituted oxindoles bearing allenyl groups in high yields and enantioselectivities (up to 92 % ee) by using a ligand with only 15 % ee. A reasonable explanation was given based on the experimental investigations and X-ray crystal structures of enantiomerically pure and racemic catalysts. Moreover, the first catalytic kinetic resolution of racemic oxindole derivatives by a [2,3] Wittig rearrangement was realized with high efficiency and stereoselectivity.
- Xu, Xi,Zhang, Jianlin,Dong, Shunxi,Lin, Lili,Lin, Xiaobin,Liu, Xiaohua,Feng, Xiaoming
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supporting information
p. 8734 - 8738
(2018/07/14)
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- Discovery of Potent Human Glutaminyl Cyclase Inhibitors as Anti-Alzheimer’s Agents Based on Rational Design
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Glutaminyl cyclase (QC) has been implicated in the formation of toxic amyloid plaques by generating the N-terminal pyroglutamate of β-amyloid peptides (pGlu-Aβ) and thus may participate in the pathogenesis of Alzheimer’s disease (AD). We designed a library of glutamyl cyclase (QC) inhibitors based on the proposed binding mode of the preferred substrate, Aβ3E?42. An in vitro structure-activity relationship study identified several excellent QC inhibitors demonstrating 5- to 40-fold increases in potency compared to a known QC inhibitor. When tested in mouse models of AD, compound 212 significantly reduced the brain concentrations of pyroform Aβ and total Aβ and restored cognitive functions. This potent Aβ-lowering effect was achieved by incorporating an additional binding region into our previously established pharmacophoric model, resulting in strong interactions with the carboxylate group of Glu327 in the QC binding site. Our study offers useful insights in designing novel QC inhibitors as a potential treatment option for AD.
- Hoang, Van-Hai,Tran, Phuong-Thao,Cui, Minghua,Ngo, Van T. H.,Ann, Jihyae,Park, Jongmi,Lee, Jiyoun,Choi, Kwanghyun,Cho, Hanyang,Kim, Hee,Ha, Hee-Jin,Hong, Hyun-Seok,Choi, Sun,Kim, Young-Ho,Lee, Jeewoo
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supporting information
p. 2573 - 2590
(2017/04/03)
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- Palladium-free and phosphine-free Sonogashira coupling reaction of aryl halides with terminal alkynes catalyzed by boehmite nanoparticle-anchored Cu(I) diethylenetriamine complex
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In this work, a novel diethylenetriamine-functionalized-boehmite nanoparticle-supported Cu(I) catalyst is synthesized. The catalyst prepared is then characterized by FT-IR spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray
- Bakherad, Mohammad,Doosti, Rahele,Mirzaee, Mahdi,Jadidi, Khosrow,Amin, Amir H.,Amiri, Omid
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p. 7347 - 7363
(2017/10/06)
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- Magnetic nanoparticle-supported tetrazole-functionalized palladium catalyst: synthesis, DFT study and application for Sonogashira and Heck cross-coupling reactions
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Abstract: A novel magnetic catalyst-immobilized nano-palladium was efficiently prepared via a (2?+?3) cycloaddition pathway and characterized with different analyses, including FT-IR, FE-SEM, EDS, XRD, TEM and VSM methods. Also, topological and NBO analysis of a simple model of the catalyst with the M06/6-311?g(d,p)-LANL2DZ model chemistry have been introduced. In addition, the catalytic pursuit of this novel magnetic nanocatalyst was successfully evaluated in Sonogashira and Heck cross-coupling reactions. Furthermore, the catalyst could be easily separated by a conventional method using a permanent magnet and reused repeatedly in the model reaction without noteworthy loss of its catalytic activity.
- Elhampour, Ali,Nemati, Firouzeh,Nahzomi, Hossein Taherpour,Mohagheghi, Vahid
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p. 6737 - 6761
(2017/10/06)
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- Development of new scaffolds as reversible tissue transglutaminase inhibitors, with improved potency or resistance to glutathione addition
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Previous studies within our group have yielded a class of cinnamoyl-based competitive reversible inhibitors for tissue transglutaminase (TG2), with Ki values as low as 1.0 μM (compound CP4d). However, due to the electrophilic nature of their al
- Apperley, Kim Y. P.,Roy, Isabelle,Saucier, Vincent,Brunet-Filion, Nicholas,Piscopo, Sara-Pier,Pardin, Christophe,De Francesco, élise,Hao, Catherine,Keillor, Jeffrey W.
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supporting information
p. 338 - 345
(2017/03/08)
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- Fe(OTf)3-catalyzed tandem Meyer-Schuster rearrangement/intermolecular hydroamination of 3-aryl propargyl alcohols for the synthesis of acyclic β-Aminoketones
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Fe(OTf)3-catalyzed synthesis of acyclic β-aminoketones from 3-aryl propargyl alcohols and nitrogen nucleophiles were investigated. Results showed that propargyl alcohols without bulky groups α to the hydroxyl group underwent the transformation smoothly. Sulphonamides exhibited the higher reactivity than amides as the nitrogen nucleophiles and the transformation of acyclic β-aminoketones were finished in shorter reaction time and higher yields. Finally, racemic fluoxetine was efficiently accessed with the present reaction as the first step. This novel synthesis of acyclic β-aminoketones probable proceeded a Fe(OTf)3-catalyzed Meyer-Schuster rearrangement of 3-aryl propargyl alcohols, followed by a intermolecular hydroamination between nitrogen nucleophiles and α, β-unsaturated ketones.
- Tao, Ruiheng,Yin, Yan,Duan, Yongbin,Sun, Yuxing,Sun, Yue,Cheng, Fengkai,Pan, Jinpeng,Lu, Cheng,Wang, Yuan
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p. 1762 - 1768
(2017/03/08)
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- Palladium supported on bis(indolyl)methane functionalized magnetite nanoparticles as an efficient catalyst for copper-free Sonogashira-Hagihara reaction
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A novel heterogeneous catalyst based on palladium nanoparticles supported on 3,3′-bisindolyl(4-hydroxyphenyl)methane functionalized magnetite (Fe3O4) nanoparticles was synthesized, characterized and used as catalyst for Sonogashira-Hagihara reaction. The alkynylation of a variety of aryl iodides and aryl bromides with terminal alkynes was carried out at 60?°C under copper and phosphane-free conditions using N,N-dimethyl acetamide as solvent, DABCO as base and low Pd loadings (0.18 mol%) under air. In the case of aryl chlorides, the reaction was carried out at 120?°C in the presence of tetra-n-butylammonium bromide (TBAB) and 0.36 mol% of Pd catalyst. The heterogeneous palladium catalyst introduced in this study is recoverable by an external magnet and it can be used for seven consecutive runs without a significant loss in catalytic activity.
- Gholinejad, Mohammad,Neshat, Abdollah,Zareh, Fatemeh,Nájera, Carmen,Razeghi, Mehran,Khoshnood, Abbas
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- Expedient synthesis of new cinnoline diones by Ru-catalyzed regioselective unexpected deoxygenation-oxidative annulation of propargyl alcohols with phthalazinones and pyridazinones
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Ruthenium-catalyzed simple, cascade and one-pot synthesis of cinnoline-fused diones has been carried out by the C-H activation of phthalazinones/pyridazinones accomplished by the unusual deoxygenation of propargyl alcohols. The bond selectivity is accredited to the traceless directing nature of the hydroxyl group of propargyl alcohol. A sequential C-H activation, insertion and deoxy-oxidative annulation has been proposed based on the preliminary mechanistic study.
- Rajkumar, Subramani,Antony Savarimuthu,Senthil Kumaran, Rajendran,Nagaraja,Gandhi, Thirumanavelan
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supporting information
p. 2509 - 2512
(2016/02/12)
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- Squaramide catalyzed enantioselective iodolactonization of allenoic acids
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An asymmetric iodolactonization reaction of allenoic acids has been extensively studied. Eight different chiral squaramides were prepared in a straightforward manner and investigated as organocatalysts. The reaction protocol is operationally simple to exe
- Kristianslund, Renate,Aursnes, Marius,Tungen, J?rn Eivind,Hansen, Trond Vidar
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supporting information
p. 5232 - 5236
(2016/11/13)
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- Assemblies of copper ferrite and palladium nanoparticles on silica microparticles as a magnetically recoverable catalyst for Sonogashira reaction under mild conditions
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Abstract Copper ferrite and palladium nanoparticles assembled on silica microparticles are prepared successfully and characterized by scanning electron microscopy, transmission electron microscopy, electron-dispersive X-ray analysis, X-ray diffraction, th
- Gholinejad, Mohammad,Ahmadi, Jahantab
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p. 973 - 979
(2015/06/08)
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- Facile and surfactant-free synthesis of Pd nanoparticles by the extract of the fruits of Piper longum and their catalytic performance for the Sonogashira coupling reaction in water under ligand- and copper-free conditions
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This work reports a facile synthesis of palladium nanoparticles (Pd NPs) by the extract of the fruits of Piper longum without any stabilizer or surfactant. The Pd NPs were found to be effective catalysts for the ligand-, amine- and copper-free Sonogashira
- Nasrollahzadeh, Mahmoud,Mohammad Sajadi,Maham, Mehdi,Ehsani, Ali
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p. 2562 - 2567
(2015/02/05)
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- Regioselective iodoazidation of alkynes: Synthesis of α,α-diazidoketones
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Aryl alkyl alkynes reacted with N-iodosuccinimide (NIS) and trimethylsilyl azide (TMSN3), leading to α,α-diazidoketones via the regioselective addition of IN3 to alkynes. Huisgen cyclization of α,α-diazidoketones generated bis-triazo
- Okamoto, Noriko,Sueda, Takuya,Minami, Hideki,Miwa, Yoshihisa,Yanada, Reiko
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supporting information
p. 1336 - 1339
(2015/03/14)
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- A novel 1,2,4-triazine-functionalized polystyrene resin-supported Pd(II) complex: A copper- and solvent-free highly efficient catalyst for Sonogashira coupling reactions
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A polystyrene-supported triazine palladium complex was prepared and characterized. The catalyst exhibits excellent catalytic activity and stability for the Sonogashira coupling reaction under ambient conditions. Various aryl halides were coupled with a number of terminal alkynes under air in the presence of 0.1 mol% of the catalyst to afford the corresponding coupled products in high yields. Furthermore, the heterogeneous catalyst can be readily recovered by simple filtration and reused for several times without a significant loss in its activity.
- Bakherad, Mohammad,Bahramian, Bahram,Jajarmi, Saeideh
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p. 405 - 409
(2013/12/04)
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- Poly(vinyl chloride)-supported Pd(II) complex as an efficient catalyst for Heck and Cu-free Sonogashira reactions under aerobic conditions
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A novel poly(vinyl chloride)-supported Pd complex was found to be a highly active catalyst for the Heck and Sonogashira reactions of aryl halides under aerobic conditions. The complex is thermally stable, and can be easily recovered and reused. The catalyst was recycled for the Heck and Sonogashira reactions for five runs without appreciable loss of its catalytic activity, and with negligible metal leaching.
- Bakherad, Mohammad,Keivanloo, Ali,Samangooei, Shahrzad
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p. 324 - 328
(2014/04/03)
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- Catalytic Asymmetric Synthesis of Alkynyl Aziridines: Both Enantiomers of cis-Aziridines from One Enantiomer of the Catalyst
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Alkynyl aziridines can be obtained from the catalytic asymmetric aziridination (AZ reaction) of alkynyl imines with diazo compounds in high yields and high asymmetric inductions mediated by a chiral boroxinate or BOROX catalyst. In contrast to the AZ reaction with aryl- and alkyl-substituted imines, alkynyl imines react to give cis-substituted aziridines with both diazo esters and diazo acetamides. Remarkably, however, the two diazo compounds give different enantiomers of the cis-aziridine from the same enantiomer of the catalyst. Theoretical considerations of the possible transition states for the enantiogenic step reveal that the switch in enantiomers results from a switch from Si-face to Re-face addition to the imine, which in turn is related to a switch from reaction with an E-imine in the former and a Z-isomer of the imine in the latter. The imine did it: The aziridination of alkynyl imines with diazo esters and diazo acetamides gives cis-aziridines with very high enantioselectivities. The absolute configuration of the cis-aziridine is reversed for the two diazo compounds even though the same enantiomer of the catalyst is used. The alkynyl imines can isomerize under the reaction conditions and the enantiomeric switch is proposed to result from the preferential reaction of E-imine with diazo esters and Z-imines with diazo acetamides.
- Guan, Yong,L?pez-Alberca, Maria P.,Lu, Zhenjie,Zhang, Yu,Desai, Aman A.,Patwardhan, Aniruddha P.,Dai, Yijing,Vetticatt, Mathew J.,Wulff, William D.
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supporting information
p. 13894 - 13900
(2016/02/18)
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- Green synthesis of water-dispersable palladium nanoparticles and their catalytic application in the ligand- and copper-free Sonogashira coupling reaction under aerobic conditions
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Pd nanoparticles were prepared from PdCl2 by green method and were characterized with UV-vis, XRD and TEM methods. Catalytic studies indicated that Pd nanoparticles exhibited high activity for ligand-, amine- and copper-free Sonogashira couplin
- Nasrollahzadeh, Mahmoud,Maham, Mehdi,Tohidi, Mohammad Mostafa
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- (BeDABCO)2Pd2Cl6 as an efficient homogeneous catalyst for copper-free Sonogashira cross-coupling reaction
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An efficient catalytic system using 1-benzyl-4-aza-1-azoniabicyclo[2.2.2] octane chloride and palladium chloride ((BeDABCO)2Pd 2Cl6) was developed for the Sonogashira reaction. In the presence of a catalytic amount of this efficient, stable homogeneous catalytic system that is non-sensitive to air and moisture, various aryl halides were efficiently coupled with phenylacetylene in good yields in H2O at 50C under copper-free conditions. Benzyl dabco as an efficient ligand and also a quaternary ammonium salt had an efficient stabilizing effect on the Pd(0) species. Copyright
- Hajipour, Abdol R.,Rafiee, Fatemeh
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p. 595 - 597
(2014/08/05)
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- Zinc-catalyzed [4+3] cycloaddition with concomitant furan annulation: Formation of cyclohepta[b]furans
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A convenient zinc-promoted [4+3] cycloaddition of a carbonyl ene-yne with simple dienes was first achieved. This reaction provided an efficient strategy to prepare various cyclohepta[b]furan rings by cascade cycloadditions. Additionally, a multicomponent reaction of dione, alkynal, and diene was also reported, which exhibited a novel strategy for selective creations of C-O bonds and C-C bonds. Go tandem! A first zinc-catalyzed tandem [4+3] cycloaddition is presented herein. Various substituted cyclohepta[b]furans were synthesized from carbonyl ene-yne and diene in moderate to good yield. Furan rings and seven-membered rings were prepared in one single step (see scheme; TBS=tert-butyldimethyl).
- Song, Bo,Li, Lian-Hua,Song, Xian-Rong,Qiu, Yi-Feng,Zhong, Mei-Jin,Zhou, Ping-Xin,Liang, Yong-Min
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supporting information
p. 5910 - 5913
(2014/05/20)
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- Original TDAE strategy using propargylic chloride: Rapid access to 1,4-diarylbut-3-ynol derivatives
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We report herein the first synthesis of propargylic alcohols using an organic reducing agent. Diarylbutynol derivatives are formed in moderate to good yields under mild conditions from the reaction of 1-(3-chloroprop-1-ynyl)-4- nitrobenzene with various aromatic aldehydes using tetrakis(dimethylamino) ethylene (TDAE) as reductant.
- Roche, Manon,Terme, Thierry,Vanelle, Patrice
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p. 1540 - 1548
(2013/04/10)
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- A dithizone-functionalized polystyrene resin-supported Pd(II) complex as an effective catalyst for Suzuki, Heck, and copper-free Sonogashira reactions under aerobic conditions in water
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A novel polystyrene-supported palladium(II) dithizone complex is found to be a highly active catalyst for the Suzuki, Heck, and Sonogashira reactions of aryl halides in water. By this protocol, aryl halides, coupled with phenyl boronic acid (Suzuki reaction), alkenes (Heck reaction) or terminal alkyne (Sonogashira reaction), smoothly affords the corresponding cross-coupling products in good to excellent yields. Furthermore, the catalyst shows good thermal stability and recyclability. The catalyst was recycled for the Suzuki, Heck, and Sonogashira reactions for five runs without appreciable loss of its catalytic activity and negligible metal leaching.
- Bakherad, Mohammad,Jajarmi, Saeideh
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p. 152 - 159
(2013/04/24)
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- Copper-And solvent-free sonogashira reaction catalyzed by polyvinyl chloride-supported palladium(ii) triazole complex
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A highly efficient method is described for the copper- and solvent-free coupling reaction of various aryl halides and terminal alkynes catalyzed by polyvinyl chloride-supported palladium (II) triazole complex. The heterogeneous catalyst used exhibits good
- Bakherad, Mohammad,Keivanloo, Ali,Bahramian, Bahram,Siavoshi, Maesoume
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p. 758 - 763
(2014/03/21)
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- Palladium nanoparticles in glycerol: A versatile catalytic system for C-X bond formation and hydrogenation processes
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Palladium nanoparticles stabilised by tris(3-sulfophenyl)phosphine trisodium salt in neat glycerol have been synthesised and fully characterised, starting from both Pd(II) and Pd(0) species. The versatility of this innovative catalytic colloidal solution has been proved by its efficient application in C-X bond formation processes (X=C, N, P, S) and C-C multiple bond hydrogenation reactions. The catalytic glycerol phase could be recycled more than ten times, preserving its activity and selectivity. The scope of each of these processes has demonstrated the power of the as-prepared catalyst, isolating the corresponding expected products in yields higher than 90%. The dual catalytic behaviour of this glycerol phase, associated to the metallic nanocatalysts used in wet medium (molecular- and surface-like behaviour), has allowed attractive applications in one-pot multi-step transformations catalysed by palladium, such as C-C coupling followed by hydrogenation, without isolation of intermediates using only one catalytic precursor. Copyright
- Chahdoura, Faouzi,Pradel, Christian,Gomez, Montserrat
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supporting information
p. 3648 - 3660
(2014/01/06)
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- Glycerol - A non-innocent solvent for Rh-catalysed Pauson-Khand carbocyclisations
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Rh-catalysed carbocyclisations of the 1,6-enynes 1-8 efficiently gave bicyclo[3.3.0]octenones in neat glycerol. Unexpectedly, ligand-free [Rh(μ-OMe)(cod)]2 was highly selective. Moreover, TPPTS [tris(3-sulfonatophenyl)phosphane trisodium salt]
- Chahdoura, Faouzi,Dubrulle, Laurent,Fourmy, Kevin,Durand, Jerome,Madec, David,Gomez, Montserrat
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p. 5138 - 5144
(2013/10/22)
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- Efficient one-pot preparation of methylthio arylbutadiynes by double elimination protocol
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A novel and efficient method for preparation of methylthio arylbutadiynes (Ar-C≡C-C≡C-SCH3) was described, and a series of compounds have been expediently obtained by the one-pot protocol starting from methylthiomethyl phenyl sulfone (MP-S) and arylpropargyl aldehydes. The mechanism was discussed on the basis of trapping and characterization of key intermediates. The results from experiments indicated that the reaction involved the initial nucleophilic addition of MP-S to arylpropargyl aldehydes to produce an intermediate carrying two leaving groups and subsequent double elimination reactions. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
- Su, Qiong,Yan, Hong,Gao, Shi-Chao,Xie, De-Xun,Cai, Qing-Yun,Shao, Guang,Peng, Zhi-Hong,An, De-Lie
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supporting information
p. 2648 - 2655
(2013/07/26)
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- First Long-Distance SRN1 on a propargylic chloride
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We report here the first example of a Long-Distance SRN1 (LD-SRN1) reaction on a propargylic chloride. The reaction of 1-(3-chloroprop-1-ynyl)-4-nitrobenzene (1) with nitronate anions led to both the formation of the C-alkylation product through an LD-SRN1 mechanism and the ethylenic compound resulting from nitrous acid elimination on the C-alkylation product 2. In contrast with previous work on LD-SRN1 reactivity, no O-alkylation product was observed. Only one original product 4 was isolated under phase transfer conditions, resulting from a nucleophilic attack by 2-nitropropane anion on the electrophilic alkyne. This LD-S RN1 reactivity did not extend to sulfinate anions; the reaction of 1 with sulfinate anions yielded original ethylenic disulfone compounds which were formed via an ionic process.
- Roche, Manon,Terme, Thierry,Vanelle, Patrice
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scheme or table
p. 4184 - 4187
(2012/08/29)
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- Solvent-free Heck and copper-free Sonogashira cross-coupling reactions catalyzed by a polystyrene-anchored Pd(II) phenyldithiocarbazate complex
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A new polystyrene-anchored Pd(II) phenyldithiocarbazate complex is synthesized and characterized. This Pd-complex behaves as an efficient heterogeneous catalyst in the Heck coupling and copper-free Sonogashira coupling reactions under aerobic conditions. Furthermore, the catalyst shows good thermal stability and recyclability.
- Bakherad, Mohammad,Keivanloo, Ali,Samangooei, Shahrzad
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p. 5773 - 5776
(2012/10/29)
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