- Palladium-Catalyzed Alkynylation and Concomitant ortho Alkylation of Aryl Iodides
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We report an efficient alkynylation reaction of aryl iodides with simultaneous ortho-alkylaton of aryl rings. The reaction between three simple reagents - aryl halides, alkynes, and alkyl halides - formed aryl-alkynyl bonds carrying hindered aryl rings in
- Lei, Chuanhu,Jin, Xiaojia,Zhou, Jianrong
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- Ethynylbenzene monolayers on gold: A metal-molecule binding motif derived from a hydrocarbon
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Exposure of a Au(111) surface to ethynylbenzene in solution leads to the formation of a bound monolayer. A chemisorption process occurs to give a stable layer consisting of oxygen-containing hydrocarbon species. Ethynylbenzene itself does not oxidize unde
- McDonagh, Andrew M.,Zareie, Hadi M.,Ford, Michael J.,Barton, Christopher S.,Ginic-Markovic, Milena,Matisons, Janis G.
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- The Reaction of Organic Molecules on Solid Surfaces. 2. An Efficient Method for the Preparation of Deuterated Alumina.
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The construction and use of simple and inexpensive device for the deuteration of alumina is described.Two methods are present for analyzing the extend of deuterating the solid: 1H NMR analysis of the water of dehydration and 1H NMR a
- Gaetano, Kevan,Pagni, Richard M.,Kabalka, George W.,Bridwell, Paula,Walsh, Elaine,et. al.
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- On the mechanism of the ruthenium-catalyzed reconstitutive condensation of allylic alcohols and terminal alkynes
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The ruthenium complex (η5C5H5)(PPh3)2RuCl (1) catalyzes the addition of allylic alcohols to terminal alkynes, yielding β,γ-unsaturated ketones. The intermediacy of a ruthenium vinylidene complex is in
- Trost, Barry M.,Kulawiec, Robert J.
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- Reaction of Organic Molecules on Solid Surfaces. 1. Facile Deuteration of Active Methylene Compounds with D2O-Treated Alumina
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A procedure has been developed for the preparation of deuterated alumina.Treatment of ketones, active methylene compounds and acidic hydrocarbons with this solid resulted in the deuteration of the compounds at acidic sites.Deuterated molecular sieves are
- Kabalka, George W.,Pagni, Richard M.,Bridwell, Paula,Walsh, Elaine,Hassaneen, Hamdi M.
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- Carbon-carbon bond forming reactions with tantalum diamidophosphine complexes that incorporate alkyne ligands
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The incorporation of o-phenylene-linked diamidophosphine ligands onto the readily available alkyne complexes Ta(alkyne)Cl3(DME) (where alkyne = hex-3-yne or 1,2-bis(trimethylsilylacetylene); DME = 1,2-dimethoxyethane) results in the formation o
- Parker, Kyle D.J.,Fryzuk, Michael D.
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- Nickel-Catalyzed Decarbonylative Cycloaddition of Benzofuran-2,3-diones with Alkynes to Flavones
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Using dppe as the ligand, the Nickel-catalyzed decarbonylative cycloaddition of benzofuran-2,3-diones with alkynes was established, and a variety of functional flavones were synthesized in 65–99% yields. Terminal alkynes with substituted phenyl groups and internal alkynes such as aryl acyl acetylenes and diphenylacetylenes are suitable for this reaction. The effects of bases on the reactions of different types of alkyne substrates were also investigated and discussed. (Figure presented.).
- Zhang, Yu-Yang,Li, Han,Jiang, Xiaoding,Subba Reddy, Chitreddy V,Liang, Hao,Zhang, Yaqi,Cao, Rihui,Sun, Raymond Wai-Yin,Tse, Man Kin,Qiu, Liqin
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p. 525 - 530
(2021/12/22)
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- Biocatalytic Site-Selective Hydrogen Isotope Exchange of Unsaturated Fragments with D2O
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Deuterated unsaturated fragments have gained increasing attention because of their roles in understanding reaction mechanisms and pharmaceutical potentials. Due to the difficulties of the existing synthetic methods, it is highly desirable to develop an ef
- Wang, Lanlan,Lou, Yujiao,Xu, Weihua,Chen, Zhichun,Xu, Jian,Wu, Qi
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p. 783 - 788
(2022/01/15)
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- Creating Dynamic Nanospaces in Solution by Cationic Cages as Multirole Catalytic Platform for Unconventional C(sp)?H Activation Beyond Enzyme Mimics
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Herein we demonstrate that, based on the creation of dynamic nanospaces in solution by highly charged positive coordination cage of [Pd6(RuL3)8]28+, multirole and multi-way cage-confined catalysis is accomplisha
- Li, Kang,Wu, Kai,Lu, Yu-Lin,Guo, Jing,Hu, Peng,Su, Cheng-Yong
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supporting information
(2021/12/14)
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- Selective Rhodium-Catalyzed Hydroformylation of Terminal Arylalkynes and Conjugated Enynes to (Poly)enals Enabled by a π-Acceptor Biphosphoramidite Ligand
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The hydroformylation of terminal arylalkynes and enynes offers a straightforward synthetic route to the valuable (poly)enals. However, the hydroformylation of terminal alkynes has remained a long-standing challenge. Herein, an efficient and selective Rh-catalyzed hydroformylation of terminal arylalkynes and conjugated enynes has been achieved by using a new stable biphosphoramidite ligand with strong π-acceptor capacity, which affords various important E-(poly)enals in good yields with excellent chemo- and regioselectivity at low temperatures and low syngas pressures.
- Zhao, Jiangui,Zheng, Xueli,Tao, Shaokun,Zhu, Yuxin,Yi, Jiwei,Tang, Songbai,Li, Ruixiang,Chen, Hua,Fu, Haiyan,Yuan, Maolin
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p. 6067 - 6072
(2021/08/16)
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- Iron(ii)-catalyzed intermolecular aziridination of alkenes employing hydroxylamine derivatives as clean nitrene sources
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The iron-catalyzed intermolecular aziridination of alkenes with hydroxylamine derivatives is described. Using simple iron(ii) sources and readily available ligands, the formal (2 + 1) cycloaddition process proved to be efficient on both styrenes and aliphatic alkenes, providing access to a wide range of aziridines. In these particularly sustainable reaction conditions, yields up to 89% could be obtained, with a catalyst loading which could be lowered to 5 mol% when the reaction was performed on large scale. Preliminary mechanistic studies suggest that both concerted and stepwise pathways are operating in this transformation. This journal is
- Berhal, Farouk,Grimaud, Laurence,Kirby, Georgina,Prestat, Guillaume,Vitale, Maxime R.
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supporting information
p. 9428 - 9432
(2021/12/09)
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- Cobalt-Catalyzed Hydroalkynylation of Vinylaziridines
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Transition metal-catalyzed hydroalkynylation reactions are efficient transformations allowing the straightforward formation of functionalized alkynes. Therein, we disclose the cobalt-catalyzed hydroalkynylation of vinylaziridines giving rise to both linea
- Biletskyi, Bohdan,Kong, Lingyu,Tenaglia, Alphonse,Clavier, Hervé
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p. 2578 - 2585
(2021/03/18)
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- B(C6F5)3-Catalyzed Sequential Additions of Terminal Alkynes to para-Substituted Phenols: Selective Construction of Congested Phenol-Substituted Quaternary Carbons
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We have developed a borane-catalyzed sequential addition of terminal alkynes to para-substituted phenols, which affords a wide range of ortho-propargylic alkylated phenols bearing congested quaternary carbons. Control experiments combined with DFT calcula
- Chen, Hui,Gao, Liuzhou,Li, Shuhua,Ni, Zhigang,Wang, Guoqiang,Yang, Mo,Zou, Jingxiang
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supporting information
p. 5533 - 5538
(2021/07/31)
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- Photoinduced catalyst-free deborylation-deuteration of arylboronic acids with D2O
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Herein, novel photoinduced catalyst-free deborylation-deuteration of arylboronic acids with D2O is reported. The protocol was compatible with a variety of functionalities, including halogen, alkoxy, cyano, sulfonyl, trimethylsilyl, trifluoromethoxy, alkyl, hydroxyl, free acid, amide, and heteroaromatic rings. A wide range of deuterated products were obtained in good yields with a high level of deuteration. This method provides a green and practical pathway to synthesize deuterium labelled compounds under mild conditions.
- Lang, Yatao,Li, Chao-Jun,Peng, Xiangjun,Zeng, Huiying
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supporting information
p. 6323 - 6327
(2020/11/09)
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- AuI-Catalyzed Hydroalkynylation of Haloalkynes
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The AuI-catalyzed reaction between terminal alkynes and aromatic haloalkynes proceeds through divergent pathways depending on the nature of the catalyst counteranion. Thus, cationic complexes containing strongly basic NHC ligands and noncoordinating anions such as BArF4 catalyze the cis haloalkynylation of the terminal alkyne, whereas introduction of a weakly basic triflate counteranion results in the stereoselective hydroalkynylation of the haloalkyne, yielding haloenyne products in good yields and complete trans selectivity. Experimental and computational studies suggest that the hydroalkynylation reaction takes place via nucleophilic attack of the terminal alkyne to the C2 carbon of the activated haloalkyne, assisted by a concerted proton abstraction by the triflate, and that the protodeauration is the turnover-limiting step, in agreement with an observed primary kinetic isotope effect.
- Diéz, Elena,Fernández, Rosario,Gómez-Bengoa, Enrique,Garciá-Fernández, Pedro D.,Iglesias-Sigu?nza, Javier,Lassaletta, José M.,Rivero-Jerez, Paula S.
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p. 16082 - 16089
(2020/10/18)
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- Iron-Promoted Domino Dehydrogenative Annulation of Deoxybenzoins and Alkynes Leading to β-Aryl-α-Naphthols
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A strategy for synthesis of β-aryl-α-naphthols has been established through an iron-promoted domino C(sp3)?H/C(sp)?H and C(sp2)?H/C(sp)?H dehydrogenative coupling of deoxybenzoins and alkynes. The synthesis uses inexpensive materials
- Zhu, Xue-Qing,Guo, Rui-Li,Zhang, Xing-Long,Gao, Ya-Ru,Jia, Qiong,Wang, Yong-Qiang
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supporting information
p. 3190 - 3201
(2020/07/13)
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- Zinc(ii)-catalyzed intramolecular hydroarylation-redox cross-dehydrogenative coupling of N -propargylanilines with diverse carbon pronucleophiles: Facile access to functionalized tetrahydroquinolines
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Zinc(ii)-catalyzed intramolecular hydroarylation-redox cross-dehydrogenative coupling of N-propargylanilines with two types of carbon pronucleophiles (nitromethane as a sp3 carbon pronucleophile and phenylacetylenes as sp carbon pronucleophiles) proceeded to give the 2-substituted tetrahydroquinolines in good yields with 100percent atomic utilization without any additional external oxidants.
- Li, Guangzhe,Wang, Chengdong,Li, Yueqing,Shao, Kun,Yu, Guo,Wang, Shisheng,Guo, Xiuhan,Zhao, Weijie,Nakamura, Hiroyuki
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supporting information
p. 7333 - 7336
(2020/07/23)
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- Pd-Catalyzed Annulation of β-Iodovinyl Sulfones with 2-Halophenols: A General Route for the Synthesis of 3-Sulfonyl Benzofuran Derivatives
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The palladium-catalyzed annulation between β-iodovinyl sulfones and 2-halophenols or 1-bromo-2-naphthol or 2-bromo-3-pyridinol is presented. The annulation process involving oxa-Michael addition-elimination and intramolecular Heck reaction leading to form
- Krishna, Gamidi Rama,Kumar, Jangam Jagadesh,Kumari, Arram Haritha,Reddy, Raju Jannapu
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supporting information
(2020/03/04)
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- Pyridine Wingtip in [Pd(Py-tzNHC)2]2+ Complex Is a Proton Shuttle in the Catalytic Hydroamination of Alkynes
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The cationic palladium(II) complex 1 of pyridyl-mesoionic carbene ligand catalyzes Markovnikov-selective intermolecular hydroamination between anilines and terminal alkynes into the corresponding imines. The reaction proceeds at room temperature, in the a
- Virant, Miha,Mihela?, Mateja,Gazvoda, Martin,Cotman, Andrej E.,Frantar, Anja,Pinter, Balazs,Ko?mrlj, Janez
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supporting information
p. 2157 - 2161
(2020/02/13)
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- Dehydrogenative Coupling of Terminal Alkynes with O/N-Based Monohydrosilanes Catalyzed by Rare-Earth Metal Complexes
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Newly synthesized rare-earth metal alkyl complexes bearing a tripyrrolyl ligand act as excellent precatalysts for the cross-dehydrogenative coupling between various terminal alkynes and O/N-based monohydrosilanes of HSi(OEt)3/HSi(NMe2)3, leading to the formation of a variety of alkoxysilylalkyne and aminosilylalkyne derivatives in good to high yields. The precatalysts LRE(CH2SiMe3)(thf)2 (RE = Y(1a), Er(1b), Yb(1c), L = 2,5-[(2-C4H3N)CPh2]2(C4H2NMe), thf = tetrahydrofuran) were easily prepared in high yields via the reactions of RE(CH2SiMe3)3(thf)2 with the proligand H2L in a single step. Mechanistic studies reveal that treatment of 1 with phenylacetylene could generate the active catalytic species: dinuclear rare-earth metal alkynides (L(thf)n[RE(μ-CCPh)]2L) (RE = Y(5a), n = 1; Yb(5c), n = 0), which could react with HSi(OEt)3 to produce the coupling product 4aa and the dinuclear rare-earth metal hydrides (L (thf)[RE(μ-H)]2L) (RE = Y(6a); Yb(6c)). By contrast, prior treatment of 1c with HSi(OEt)3 proceeds via cleavage of the Si-O bond to produce the dinuclear ytterbium alkoxide (LYb(μ-OEt))2 7c, which is inert in the dehydrogenative coupling reaction. The results of the mechanistic studies are consistent with the observation that the reaction is greatly influenced by the addition sequence of precatalyst/alkynes/silanes.
- Guo, Dianjun,Huang, Zeming,Pan, Mengke,Sheng, Tian,Wang, Shaowu,Zha, Ling,Zhou, Shuangliu,Zhu, Xiancui
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supporting information
p. 14152 - 14161
(2020/10/09)
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- An unexpected coupling-reduction tandem reaction for the synthesis of alkenyl-substituted BODIPYs
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We report an unexpected coupling-reduction tandem reaction as a general and efficient one-pot synthesis of alkenyl-substituted boron dipyrromethene (BODIPY) from chlorinated-BODIPY and alkyne. This unique synthesis combined the Sonogashira coupling reaction and reduction reaction without adding an additional reagent, which shows higher yields, broader substrate scope and faster reaction rate compared with the conventional methods of the Knoevenagel reaction and Heck coupling reaction.
- Teng, Kun-Xu,Niu, Li-Ya,Li, Jie,Jia, Lu,Yang, Qing-Zheng
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supporting information
p. 13761 - 13764
(2019/11/19)
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- Alkylation of Terminal Alkynes under Zinc Lewis Acid Catalysis and Its Mechanistic Studies
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With a zinc Lewis acid catalyst and proton sponge in toluene, terminal alkynes were found to undergo the alkylation by alkyl triflates to provide unsymmetrical internal alkynes. This is the first example that a simple alkyl chain other than benzylic and norbornyl units can be introduced onto the alkynyl carbon atom under Lewis acid catalysis. Mechanistic studies revealed that the activation of the alkyne by the zinc Lewis acid and proton sponge is the trigger of the reaction to give a monoalkynylzinc species, which successively reacts with the alkyl triflate to afford the internal alkyne. A radical pathway is unlikely in this system. (Figure presented.).
- Osano, Mana,Kida, Takeru,Yonekura, Kyohei,Tsuchimoto, Teruhisa
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supporting information
p. 2825 - 2831
(2019/04/13)
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- Self-assembly of catalytically active supramolecular coordination compounds within metal?organic frameworks
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Supramolecular coordination compounds (SCCs) represent the power of coordination chemistry methodologies to self-assemble discrete architectures with targeted properties. SCCs are generally synthesized in solution, with isolated fully coordinated metal atoms as structural nodes, thus severely limited as metal-based catalysts. Metal?organic frameworks (MOFs) show unique features to act as chemical nanoreactors for the in situ synthesis and stabilization of otherwise not accessible functional species. Here, we present the self-assembly of PdII SCCs within the confined space of a pre-formed MOF (SCCs@MOF) and its post-assembly metalation to give a PdII?AuIII supramolecular assembly, crystallography underpinned. These SCCs@MOFs catalyze the coupling of boronic acids and/or alkynes, representative multi-site metal-catalyzed reactions in which traditional SCCs tend to decompose, and retain their structural integrity as a consequence of the synergetic hybridization between SCCs and MOFs. These results open new avenues in both the synthesis of novel SCCs and their use in heterogeneous metal-based supramolecular catalysis.
- Adam, Rosa,Mon, Marta,Greco, Rossella,Kalinke, Lucas H.G.,Vidal-Moya, Alejandro,Fernandez, Antonio,Winpenny, Richard E.P.,Domenech-Carbo, Antonio,Leyva-Perez, Antonio,Armentano, Donatella,Pardo, Emilio,Ferrando-Soria, Jesus
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supporting information
p. 10350 - 10360
(2019/08/20)
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- Self-Assembly of Catalytically Active Supramolecular Coordination Compounds within Metal-Organic Frameworks
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Supramolecular coordination compounds (SCCs) represent the power of coordination chemistry methodologies to self-assemble discrete architectures with targeted properties. SCCs are generally synthesized in solution, with isolated fully coordinated metal atoms as structural nodes, thus severely limited as metal-based catalysts. Metal-organic frameworks (MOFs) show unique features to act as chemical nanoreactors for the in situ synthesis and stabilization of otherwise not accessible functional species. Here, we present the self-assembly of PdII SCCs within the confined space of a pre-formed MOF (SCCs?MOF) and its post-assembly metalation to give a PdII-AuIII supramolecular assembly, crystallography underpinned. These SCCs?MOFs catalyze the coupling of boronic acids and/or alkynes, representative multi-site metal-catalyzed reactions in which traditional SCCs tend to decompose, and retain their structural integrity as a consequence of the synergetic hybridization between SCCs and MOFs. These results open new avenues in both the synthesis of novel SCCs and their use in heterogeneous metal-based supramolecular catalysis.
- Adam, Rosa,Mon, Marta,Greco, Rossella,Kalinke, Lucas H. G.,Vidal-Moya, Alejandro,Fernandez, Antonio,Winpenny, Richard E. P.,Doménech-Carbó, Antonio,Leyva-Pérez, Antonio,Armentano, Donatella,Pardo, Emilio,Ferrando-Soria, Jesús
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supporting information
p. 10350 - 10360
(2019/08/27)
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- Mechanistic Insight into Catalytic Redox-Neutral C-H Bond Activation Involving Manganese(I) Carbonyls: Catalyst Activation, Turnover, and Deactivation Pathways Reveal an Intricate Network of Steps
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Manganese(I) carbonyl-catalyzed C-H bond functionalization of 2-phenylpyridine and related compounds containing suitable metal directing groups has recently emerged as a potentially useful synthetic methodology for the introduction of various groups to th
- Hammarback, L. Anders,Robinson, Alan,Lynam, Jason M.,Fairlamb, Ian J.S.
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p. 2316 - 2328
(2019/03/02)
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- Organoiron- And Fluoride-Catalyzed Phosphinidene Transfer to Styrenic Olefins in a Stereoselective Synthesis of Unprotected Phosphiranes
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Catalytic phosphiranation has been achieved, allowing preparation of trans-1-R-2-phenylphosphiranes (R = t-Bu: 1-t-Bu; i-Pr: 1-i-Pr) from the corresponding dibenzo-7-(R)-7-phospha-norbornadiene (RPA, A = C14H10, anthracene) and styre
- Geeson, Michael B.,Transue, Wesley J.,Cummins, Christopher C.
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supporting information
p. 13336 - 13340
(2019/09/10)
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- Substrate-Controlled Divergent Synthesis of Enaminones and Pyrroles from Indolizines and Nitroso Compounds
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It is imperative to learn new synthetic transformations to succeed in drug discovery and development. We report the substrate-driven synthesis of β-enaminones and N-aryl pyrroles from indolizines and nitrosoarenes; aryl-substituted indolizines lead to β-enaminones in a regio- and diastereoselective manner, whereas alkyl-substituted indolizines produce tetrasubstituted pyrroles. All products contain a pyridine unit, the second most abundant ring (after phenyl) in the FDA Orange Book. In both cases, the reactions proceed at room temperature without any catalyst. Moreover, both types of products can be obtained in one pot from commercial materials as well as at a gram scale. It is worthy of note that the regioselectivity of the β-enaminones is inaccessible by the standard literature methods and their utility has been exemplified in the synthesis of diverse heterocycles. We have made every endeavor to put forward the corresponding reaction mechanisms based on thorough experimental work. (Figure presented.).
- González-Soria, María José,Alonso, Francisco
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p. 5005 - 5017
(2019/11/03)
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- Hydrogen-Bond-Promoted Metal-Free Hydroamination of Alkynes
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An original metal-free regio- A nd stereoselective intermolecular hydroamination of alkynes is described. Various (E)-enamines were obtained from arylacetylenes and aliphatic secondary amines in the presence of ethylene glycol as a solvent. The latter is
- Bahri, Janet,Monnier, Florian,Ollevier, Thierry,Taillefer, Marc,Tanbouza, Nour
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supporting information
p. 2086 - 2090
(2019/11/05)
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- Cyclopropanations via Heme Carbenes: Basic Mechanism and Effects of Carbene Substituent, Protein Axial Ligand, and Porphyrin Substitution
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Catalytic carbene transfer to olefins is a useful approach to synthesize cyclopropanes, which are key structural motifs in many drugs and biologically active natural products. While catalytic methods for olefin cyclopropanation have largely relied on rare transition-metal-based catalysts, recent studies have demonstrated the promise and synthetic value of iron-based heme-containing proteins for promoting these reactions with excellent catalytic activity and selectivity. Despite this progress, the mechanism of iron-porphyrin and hemoprotein-catalyzed olefin cyclopropanation has remained largely unknown. Using a combination of quantum chemical calculations and experimental mechanistic analyses, the present study shows for the first time that the increasingly useful C-C functionalizations mediated by heme carbenes feature an FeII-based, nonradical, concerted nonsynchronous mechanism, with early transition state character. This mechanism differs from the FeIV-based, radical, stepwise mechanism of heme-dependent monooxygenases. Furthermore, the effects of the carbene substituent, metal coordinating axial ligand, and porphyrin substituent on the reactivity of the heme carbenes was systematically investigated, providing a basis for explaining experimental reactivity results and defining strategies for future catalyst development. Our results especially suggest the potential value of electron-deficient porphyrin ligands for increasing the electrophilicity and thus the reactivity of the heme carbene. Metal-free reactions were also studied to reveal temperature and carbene substituent effects on catalytic vs noncatalytic reactions. This study sheds new light into the mechanism of iron-porphyrin and hemoprotein-catalyzed cyclopropanation reactions and it is expected to facilitate future efforts toward sustainable carbene transfer catalysis using these systems.
- Wei, Yang,Tinoco, Antonio,Steck, Viktoria,Fasan, Rudi,Zhang, Yong
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p. 1649 - 1662
(2018/02/17)
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- Cobalt(II)-based Metalloradical Activation of 2-(Diazomethyl)pyridines for Radical Transannulation and Cyclopropanation
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A new catalytic method for the denitrogenative transannulation/cyclopropanation of in-situ-generated 2-(diazomethyl)pyridines is described using a cobalt-catalyzed radical-activation mechanism. The method takes advantage of the inherent properties of a CoIII-carbene radical intermediate and is the first report of denitrogenative transannulation/cyclopropanation by a radical-activation mechanism, which is supported by various control experiments. The synthetic benefits of the metalloradical approach are showcased with a short total synthesis of (±)-monomorine.
- Roy, Satyajit,Das, Sandip Kumar,Chattopadhyay, Buddhadeb
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supporting information
p. 2238 - 2243
(2018/02/19)
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- Z-Selective Addition of Diaryl Phosphine Oxides to Alkynes via Photoredox Catalysis
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Radical addition to alkynes is known to predominantly yield thermodynamically more stable E-alkenes. Control of stereoselectivity in these reactions, and the isolation of the higher-energy Z-alkenes, remain an important challenge in chemical synthesis. Herein, direct synthesis of Z-alkenylphosphine oxides via visible-light-induced radical addition to alkynes in water is reported. This protocol was effective with various terminal and internal alkynes, affording products with high Z-stereoselectivity. Moreover, this transformation was demonstrated on gram scale. Mechanistic studies support the following conclusions: (1) the reaction proceeds via free-radical addition; (2) the choice of K2CO3 as aqueous base is crucial to the transformation; and (3) π-π stacking interaction greatly improves Z-selectivity.
- Wang, Huamin,Li, Yongli,Tang, Zilu,Wang, Shengchun,Zhang, Heng,Cong, Hengjiang,Lei, Aiwen
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p. 10599 - 10605
(2018/10/25)
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- Transition-Metal-Free Catalytic Formal Hydroacylation of Terminal Alkynes
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Although hydroacylation is a very useful reaction for producing ketones from aldehydes with 100% atom efficiency, classical Rh-catalyzed hydroacylation presents several problems, including the need for transition metal catalysts, unwanted decarbonylation of aldehydes, and difficulty in regioselectivity control. However, formal hydroacylation utilizing the nucleophilicity of terminal alkynes can avoid these problems. In this work, we have achieved transition-metal-free formal hydroacylation of terminal alkynes using an Mg3Al-CO3-layered double hydroxide as a heterogeneous catalyst. This system was applicable to the efficient synthesis of α,β-unsaturated ketones with various substituents, and the catalyst can be reused without a significant loss of catalytic performance.
- Yatabe, Takafumi,Mizuno, Noritaka,Yamaguchi, Kazuya
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p. 11564 - 11569
(2018/11/23)
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- T-BuOK-mediated reductive addition of P(O)-H compounds to terminal alkynes forming β-arylphosphine oxides
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A novel and efficient t-BuOK-mediated reductive addition of P(O)-H compounds to terminal alkynes was developed. A variety of β-arylphosphine oxides including the valuable β-heteroarylphosphine oxides were produced in moderate to high yields under mild reaction conditions. This reaction may proceed via a tandem process involving regio-selective double addition and subsequent transfer hydrogenation.
- Zhang, Ji-Shu,Zhang, Jian-Qiu,Chen, Tieqiao,Han, Li-Biao
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supporting information
p. 5462 - 5467
(2017/07/12)
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- Organocatalytic Imidazolium Ionic Liquids H/D Exchange Catalysts
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Simple 1,2,3-trialkylimidazolium cation associated with basic anions, such as hydrogen carbonate, prolinate, and imidazolate, is an active catalyst for the H/D exchange reaction of various substrates using CDCl3 as D source, without the addition of any extra bases or metal. High deuterium incorporation (up to 49%) in acidic C-H bonds of ketone and alkyne substrates (pKa from 18.7 to 28.8) was found at room temperature. The reaction proceeds through the fast and reversible deuteration of the 2-methyl H of the imidazolium cation followed by D transfer to the substrate. The IL acts as a neutral base catalyst in which the contact ion pair is maintained in the course of the reaction. The basic active site is due to the presence of a remote basic site in the anion namely, OH of bicarbonate, NH of prolinate, and activated water in the imidazolate anion. Detailed kinetic experiments demonstrate that the reaction is first order on the substrate and pseudozero order relative to the ionic liquid, due to the fast reversible reaction involving the deuteration of the ionic liquid by the solvent.
- Zanatta, Marcileia,Dos Santos, Francisco P.,Biehl, Cristina,Marin, Graciane,Ebeling, Gunter,Netz, Paulo A.,Dupont, Jairton
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supporting information
p. 2622 - 2629
(2017/03/14)
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- Isolation and characterization of hydrocarbon soluble NHC copper(I) phosphoranimide complex and catalytic application for alkyne hydroboration reaction
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Novel NHC copper(I) phosphoranimide complexes have been isolated and characterized by NMR and X-ray crystallography studies. The feature of this hydrocarbon soluble mononuclear copper complex as effective hydroboration catalyst could be attributed to the
- Bai, Tao,Yang, Yanhui,Han, Chao
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supporting information
p. 1523 - 1527
(2017/03/23)
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- DNA-supported palladium nanoparticles as a reusable catalyst for the copper- and ligand-free Sonogashira reaction
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DNA nanotechnology has recently emerged as a powerful discipline with diverse applications. However, studies focused on the combination of DNA and metal nanoparticles for catalyst design are scanty. We have prepared a catalyst composed of palladium nanoparticles supported on DNA which has been characterised by TEM, SEM, EDX, UV, FTIR and XPS. The catalyst, mainly composed of Pd(ii) and Pd(iv) species in the form of oxides, has been effectual in the copper- and ligand-free Sonogashira-Hagihara coupling of aryl iodides with terminal aromatic and aliphatic alkynes. The products are obtained in 54-86% isolated yields using low catalyst loading (0.5 mol%) under mild conditions (65 °C) in methanol without air exclusion. Moreover, the catalyst can be easily recovered and reused in five cycles and shows better performance than an array of commercial palladium catalysts. The mechanistic aspects of the reaction are also tackled in detail.
- Camacho, Ana Silvia,Martín-García, Iris,Contreras-Celedón, Claudia,Chacón-García, Luis,Alonso, Francisco
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p. 2262 - 2273
(2017/07/24)
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- Transition-Metal-Free Terminal Alkyne Addition to Isatins
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A 'direct' alkynylation of isatins, which uses potassium tert-butoxide to provide the desired 3-hydroxy-3-ethynyl-2-oxindoles in good to high yields, is reported. This protocol proceeds smoothly for both electron-rich and electron-deficient alkynes in com
- Dhara, Kalyan,Kapat, Ajoy,Ghosh, Tridev,Dash, Jyotirmayee
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p. 4226 - 4268
(2016/11/26)
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- Copper-Catalyzed anti-Markovnikov Hydroindolation of Terminal Alkynes: Regioselective Synthesis of Bis(indolyl)alkanes
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An efficient copper-catalyzed intermolecular hydroindolation reaction of terminal aryl alkynes to expeditiously synthesize bis(indolyl)alkanes in moderate to high yields is described. The double nucleophilic addition of two molecules of indole to one mole
- Srivastava, Ananya,Patel, Shyam Sunder,Chandna, Nisha,Jain, Nidhi
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p. 11664 - 11670
(2016/12/09)
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- Hypervalent iodine(III)-mediated benzannulation of enamines with alkynes: An efficient synthesis of substituted aminonaphthoic acid derivatives
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An intermolecular two C-C bond formation procedure for the synthesis of carbocycles mediated by hypervalent iodine(III) reagents was developed. This metal free protocol provided a new approach for the synthesis of useful substituted 1-amino-2-naphthoic ac
- Gao, Peng,Fan, Mingjin,Bai, Zijing,Wei, Yunyang
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supporting information
p. 479 - 485
(2015/04/22)
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- A stable N-heterocyclic carbene organocatalyst for hydrogen/deuterium exchange reactions between pseudoacids and deuterated chloroform
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It was observed that the stable and commercially available N-heterocyclic carbene (NHC) 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, the so-called IDipp, catalyzes hydrogen/deuterium exchange reactions between pseudoacids and chloroform-d1
- Perez, Fabien,Ren, Yajun,Boddaert, Thomas,Rodriguez, Jean,Coquerel, Yoann
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p. 1092 - 1097
(2015/01/30)
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- RhII-catalyzed [3+2] cycloaddition of 2 H-azirines with N-sulfonyl-1,2,3-triazoles
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RhII-catalyzed intermolecular [3+2] cycloaddition of 2 H-azirines with N-sulfonyl-1,2,3-triazoles is disclosed, in which a series of fully functionalized pyrroles is produced via rhodium azavinyl carbene intermediates. A distinct feature of this reaction is that the azavinyl carbene serves as a [2 C] equivalent, instead of as [1 C] or aza-[3 C] synthons, which have been reported previously in cyclopropanations and [3 + n] cycloadditions. Moreover, this methodology has also been successfully applied in the total synthesis of URB447 as well as the formal synthesis of Atorvastatin (Lipitor).
- Zhao, Yun-Zhou,Yang, Hai-Bin,Tang, Xiang-Ying,Shi, Min
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supporting information
p. 3562 - 3566
(2015/03/04)
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- Characterization and phenylacetylene-assisted cyclometalation of an isolable hydrido-selenolato PtII complex having phosphite ligands, cis-[PtH(SeTrip){P(OPh)3}2]#
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A hydridoselenolato PtII complex having P(OPh)3 ligands, cis-[PtH(SeTrip){P(OPh)3}2] (Trip: 9-triptycyl), was synthesized by the reaction of TripSeH with [Pt{P(OPh)3} 2]. The structure was characterized by NMR spectroscopy and X-ray crystallography in comparison with the corresponding PPh3 complex, cis-[PtH(SeTrip)(PPh3)2], indicating the stronger coordination of P(OPh)3 to the Pt center than that of PPh 3. On heating at 130 °C in xylene for 17 h, cis-[PtH(SeTrip)- {P(OPh)3}2] was converted to the corresponding 1,2-selenaplatinacycle (SP-42)-[Pt(kC1,kSe9-TripSe(2-)) {P(OPh)3}2] through an intramolecular cyclization (cyclometalation). The reaction with dimethyl acetylenedicarboxylate (DMAD) gave a mixture of hydroselenation products (E)- and (Z)-(MeO2C)CH= C(SeTrip)CO2Me non-stereoselectively together with 1H-2-benzoselenin, dimethyl 7H-7,11b[1',2']-benzenoanthra[9,1-bc]selenin-2,3-dicarboxylate. In the reaction with phenylacetylene in toluene at 110 °C, phenylacetylene served as a hydrogen acceptor to form the 1,2-selenaplatinacycle and styrene. Based on the results of controlled experiments using cis-[PtD(SeTrip){P(OPh) 3}2] and phenylacetylene-d, the mechanism of the cyclometalation was proposed as the 1,2- (major) and 2,1- (minor) insertions of phenylacetylene into the Pt-H bond followed by cyclometalation between the Pt center and the triptycyl group. The reaction with phenylacetylene in the presence of excess P(OPh)3 furnished a 1,2,3-oxaphosphaplatinacycle, (SP-4-2)-[Pt{kC,kP-(Z)-CH=C(Ph)-OP(OPh)2}(SeTrip){P(OPh) 3}], as a minor product, together with the 1,2-selenaplatinacycle in a decreased yield.
- Kamon, Hitomi,Aoki, Yutaro,Nakata, Norio,Ishii, Akihiko
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p. 274 - 282
(2014/03/21)
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- Palladium-catalyzed carbonylative addition of aryl bromides to arylalkynes: A simple and efficient method for chalcone synthesis
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Palladium-catalyzed carbonylative addition of aryl bromides to terminal arylalkynes was carried out to produce chalcones in satisfactory to excellent yields. The unprecedented carbonylation reaction proceeded smoothly under mild conditions in the presence
- Zhang, Sheng,Wang, Liangguang,Feng, Xiujuan,Bao, Ming
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supporting information
p. 7233 - 7237
(2014/11/07)
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- Synthesis and reactivity of a terminal scandium imido complex
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Preparation of a terminal scandium imido complex, 2·DMAP, was accomplished through thermolysis of an arylamido methyl complex, 1, stabilized by a bulky β-diketiminato ligand in the presence of 4-N,N- dimethylaminopyridine (DMAP). Mechanistic studies revealed that the reaction proceeds by initial metalation of 1, followed by rapid DMAP-promoted alkane elimination to generate the scandium imido complex. Kinetic studies of the reaction between separately synthesized metalate 3 and DMAP under pseudo-first-order conditions yielded activation parameters of ΔH a = 73.5(2) kJ mol-1 and ΔS a = -70.4(5) J K-1 mol-1. The reaction of 2·DMAP with tert-butyl amine or phenylacetylene resulted in addition of the N-H or C-H bond across the scandium imide linkage, respectively, to furnish complexes endo-/exo-4 and endo-5. These compounds were fully characterized, including via structural analysis, providing further evidence for the terminal scandium imido derivative 2·DMAP.
- Chu, Terry,Piers, Warren E.,Dutton, Jason L.,Parvez, Masood
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p. 1159 - 1165
(2013/05/09)
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- Mild reaction conditions for the terminal deuteration of alkynes
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Routinely employed syntheses of terminally deuterated alkynes often utilize strong bases (i.e., LDA, n-BuLi, or Grignard reagents) or low (i.e., -78 °C) or elevated (i.e., 56 °C) reaction temperatures; furthermore many of these procedures afford average y
- Bew, Sean P.,Hiatt-Gipson, Glyn D.,Lovell, Jenny. A.,Poullain, Christophe
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supporting information; experimental part
p. 456 - 459
(2012/03/26)
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- Stereodefined construction of trisubstituted alkenes by direct coupling reaction of allylating agents, alkynes, and organoboranes
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Stereo-defined construction of trisubstituted alkenes by direct coupling reaction of allylating agents, alkynes, and organoboranes was reported. A two-necked round-bottomed flask equipped with a rubber septum and an air condenser, at the top of which was
- Fukushima, Masahiro,Takushima, Daiki,Satomura, Hideaki,Onodera, Gen,Kimura, Masanari
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supporting information; experimental part
p. 8019 - 8023
(2012/08/27)
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- Gold-catalysed oxyarylation of styrenes and mono- and gem-disubstituted olefins facilitated by an iodine(III) oxidant
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1-Hydroxy-1,2-benziodoxol-3(1H)-one (IBA) is an efficient terminal oxidant for gold-catalysed, three-component oxyarylation reactions. The use of this iodine(III) reagent expands the scope of oxyarylation to include styrenes and gem-disubstituted olefins, substrates that are incompatible with the previously reported Selectfluor-based methodology. Diverse arylsilane coupling partners can be employed, and in benzotrifluoride, homocoupling is substantially reduced. In addition, the IBA-derived co-products can be recovered and recycled. The I's have it: The unprecedented use of an iodine(III) reagent as the terminal oxidant for gold-catalysed oxyarylation allows the substrate scope to be significantly expanded; in addition to monosubstituted olefins, styrenes and gem-disubstituted olefins are well tolerated (see scheme). With benzotrifluoride as solvent, unproductive homodimerisation of the arylsilane coupling partner is effectively suppressed. Copyright
- Ball, Liam T.,Lloyd-Jones, Guy C.,Russell, Christopher A.
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supporting information; experimental part
p. 2931 - 2937
(2012/04/23)
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- General and selective head-to-head dimerization of terminal alkynes proceeding via hydropalladation pathway
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A general highly regio- and stereoselective palladium-catalyzed head-to-head dimerization reaction of terminal acetylenes is presented. This methodology allows for the efficient synthesis of a variety of 1,4-enynes as single E stereoisomers. Computational studies reveal that this dimerization reaction proceeds via the hydropalladation pathway.
- Jahier, Claire,Zatolochnaya, Olga V.,Zvyagintsev, Nickolay V.,Ananikov, Valentine P.,Gevorgyan, Vladimir
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supporting information; experimental part
p. 2846 - 2849
(2012/07/17)
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- Zinc(II)-catalyzed redox cross-dehydrogenative coupling of propargylic amines and terminal alkynes for synthesis of N-tethered 1,6-enynes
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The zinc(II)-catalyzed redox cross-dehydrogenative coupling (CDC) of propargylic amines and terminal alkynes proceeds to afford N-tethered 1,6-enynes. In the current CDC reaction, a C(sp)-C(sp3) bond is formed between the carbon adjacent to the nitrogen atom in the propargylic amine and the terminal carbon of the alkyne with reduction of the C-C triple bond of the propargylic amine, which acts as an internal oxidant.
- Sugiishi, Tsuyuka,Nakamura, Hiroyuki
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supporting information; experimental part
p. 2504 - 2507
(2012/03/27)
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- Three-component coupling of aldehydes, amines, and alkynes catalyzed by oxidized copper nanoparticles on titania
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Copper nanoparticles (mainly as Cu2O) on titania have been shown to catalyze the multicomponent synthesis of propargylamines from aldehydes, amines, and alkynes (A3 coupling) effectively at 70 °C under solvent-free conditions. Both aromatic and aliphatic aldehydes and alkynes have been combined with secondary amines to provide a wide range of propargylamines in moderate to excellent yields. Two examples of ketone/amine/alkyne (KA 2) coupling are also included. The catalyst is easy to prepare, reusable at a low copper loading (0.5 mol-%), and exhibits higher catalytic activity than some commercially available copper sources. Some mechanistic aspects of the reaction have also been examined, which have unveiled the participation of copper(I) acetylides in a heterogeneous process. Copyright
- Albaladejo, Maria Jose,Alonso, Francisco,Moglie, Yanina,Yus, Miguel
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experimental part
p. 3093 - 3104
(2012/06/30)
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- Organoactinide-, Organolanthanide-, and OrganoGroup-4-Mediated Hydrothiolation of Terminal Alkynes with Aliphatic, Aromatic and Benzylic Thiols
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An efficient and highly Markovnikov selective organoactinide-, organolanthanide-, and organozirconium-catalyzed addition of aryl, benzyl, and aliphatic thiols to terminal alkynes is described. The corresponding vinyl sulfides are produced with little or n
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Page/Page column 12
(2011/04/14)
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- Amphoteric α-boryl aldehydes
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A new class of stable molecules, α-boryl aldehydes, has been prepared from oxiranyl N-methyliminodiacetyl boronates by a 1,2-boryl migration with concomitant epoxide scission. A range of boryl imines, alkenes, alcohols, acids, enol ethers, enamides, and other functionalized boronic acid derivatives that are difficult or impossible to prepare using established protocols can be accessed from α-boryl aldehydes. The chemoselective transformations of these building blocks, including the facile synthesis of functionalized unnatural amino acids from silyloxy and amido vinyl boronates, attest to the potential of α-boryl aldehydes in chemical synthesis.
- He, Zhi,Yudin, Andrei K.
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supporting information; experimental part
p. 13770 - 13773
(2011/10/05)
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- Multicomponent click synthesis of 1,2,3-triazoles from epoxides in water catalyzed by copper nanoparticles on activated carbon
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Copper nanoparticles on activated carbon have been found to effectively catalyze the multicomponent synthesis of Β-hydroxy-1,2,3-triazoles from a variety of epoxides and alkynes in water. The catalyst is easy to prepare, reusable at a low copper loading (
- Alonso, Francisco,Moglie, Yanina,Radivoy, Gabriel,Yus, Miguel
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scheme or table
p. 8394 - 8405
(2011/12/04)
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- Indium(III)-catalyzed coupling between alkynes and aldehydes to α,β-unsaturated ketones
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The combined use of a catalytic amount of InX3 (X = OTf and NTf2) and 1-butanol was found to be effective in formal alkynealdehyde metathesis. With this catalytic system, aromatic alkynes reacted with aromatic aldehydes to give chalcones in moderate to good yields. Alkynals were efficiently converted into 5- to 7-membered cyclic compounds by intramolecular alkyne-aldehyde coupling.
- Miura, Katsukiyo,Yamamoto, Kiyomi,Yamanobe, Aya,Ito, Keisuke,Kinoshita, Hidenori,Ichikawa, Junji,Hosomi, Akira
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supporting information; experimental part
p. 766 - 767
(2011/01/09)
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