- Method for preparing 3-alkynyl indole compound by using gold complex
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The invention relates to a method for preparing a 3-alkynyl indole compound by using a gold complex, which comprises the following steps of: by taking indole and terminal alkyne as raw materials, a gold complex containing ortho-carborane Schiff base ligand as a catalyst and air as an oxidant, carrying out oxidative coupling reaction at room temperature to obtain the 3-alkynyl indole compound. Compared with the prior art, the method has the advantages that the gold complex containing the ortho-carborane Schiff base ligand is used as the catalyst, indole and terminal alkyne can be catalyzed to react under the condition that air is used as an oxidizing agent to prepare the 3-alkynyl indole compound, the usage amount of the catalyst is low, the reaction condition is mild, the reaction atom economy is high, waste emission is little, the substrate is high in universality, the raw materials are cheap and easy to obtain, the product yield is high, and the method has a wide application prospect in industry.
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Paragraph 0048-0059
(2021/07/17)
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- Highly regioselective synthesis of 2,4,5-(hetero)aryl substituted oxazoles by intermolecular [3+2]-cycloaddition of unsymmetrical internal alkynes
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A robust N-nucleophilic 1,3-N,O-dipole equivalent reacts with unsymmetrical internal alkynes under gold catalysis. Conjugation from a remote nitrogen lone pair enables and controls this convergent and highly regioselective process.
- Chatzopoulou, Elli,Davies, Paul W.
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supporting information
p. 8617 - 8619
(2013/09/23)
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- Arylsulfonylacetylenes as alkynylating reagents
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The unexpected anti-Michael addition of RLi to β-substituted sulfonylacetylenes, followed by in situ elimination of the ion sulfinate, allows the alkynylation of C(sp2) and C(sp3). Aryl and heteroaryl acetylenes, enynes, and mono and dialkyl alkynes can be obtained in very high yields under very mild conditions, avoiding the use of transition metals as catalysts and, in many cases, haloderivatives as starting materials. Furthermore, the use of lithium 2-p-tolylsulfinyl benzylcarbanions as nucleophiles of these reactions allows their stereocontrolled alkynylation, affording enantiomerically pure alkynes or enantioenriched allenes depending on the protonating agent (NH4Cl or H2O).
- Marzo, Leyre,Aleman, Jose,Garcia Ruano, Jose Luis
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p. 403 - 407
(2013/07/26)
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- Arylsulfonylacetylenes as alkynylating reagents of C sp 2 -H bonds activated with lithium bases
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Chameleon: A new strategy for the synthesis of a wide variety of alkynyl derivatives by the reaction of substituted arylsulfonylacetylenes with organolithium species is described (see scheme). The high yields, the simplicity of the experimental procedure, the broad scope of this reaction, and the formation of Csp-C sp 2 bonds without using transition metals are the main features of this methodology. Copyright
- Garcia Ruano, Jose Luis,Aleman, Jose,Marzo, Leyre,Alvarado, Cuauhtemoc,Tortosa, Mariola,Diaz-Tendero, Sergio,Fraile, Alberto
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supporting information; experimental part
p. 2712 - 2716
(2012/04/17)
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- Expanding the scope of arylsulfonylacetylenes as alkynylating reagents and mechanistic insights in the formation of Csp2-Csp and Csp 3-Csp bonds from organolithiums
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We describe the unexpected behavior of the arylsulfonylacetylenes, which suffer an "anti-Michael" addition of organolithiums producing their alkynylation under very mild conditions. The broad scope, excellent yields, and simplicity of the experimental procedure are the main features of this methodology. A rational explanation of all these results can be achieved by theoretical calculations, which suggest that the association of the organolithiums to the electrophile is a previous step of their intramolecular attack and is responsible for the unexpected "anti-Michael" reactions observed for substituted sulfonylacetylenes. A calculated conclusion: A new transition-metal-free strategy for the synthesis of any kind of alkynyl derivatives in high yields in the reaction of organolithium species with arylsulfonylacetylenes is presented (see scheme). Theoretical calculations provide a rational explanation and suggest that association of the organolithium to the electrophile is a previous step of their intramolecular attack and is responsible for the "anti-Michael" reaction. Copyright
- Garcia Ruano, Jose Luis,Aleman, Jose,Marzo, Leyre,Alvarado, Cuauhtemoc,Tortosa, Mariola,Diaz-Tendero, Sergio,Fraile, Alberto
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supporting information; experimental part
p. 8414 - 8422
(2012/07/27)
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- Ethynyl benziodoxolones for the direct alkynylation of heterocycles: Structural requirement, improved procedure for pyrroles, and insights into the mechanism
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This report describes a full study of the gold-catalyzed direct alkynylation of indoles, pyrroles, and thiophenes using alkynyl hypervalent iodine reagents, especially the study of the structural requirements of alkynyl benziodoxolones for an efficient acetylene transfer to heterocycles. An improved procedure for the alkynylation of pyrroles using pyridine as additive is also reported. Nineteen alkynyl benziodoxol(on)es were synthesized and evaluated in the direct alkynylation of indoles and/or thiophenes. Bulky silyl groups as acetylene substituents were optimal. Nevertheless, transfer of aromatic acetylenes to thiophene was achieved for the first time. An accelerating effect of a methyl substituent in both the 3-and 6-position of triisopropylsilylethynyl-1,2-benziodoxol-3(1H)-one (TIPS-EBX) on the reaction rate was observed. Competitive experiments between substrates of different nucleophilicity, deuterium labeling experiments, as well as the regioselectivity observed are all in agreement with electrophilic aromatic substitution. Gold(III) 2-pyridinecarboxylate dichloride was also an efficient catalyst for the reaction. Investigations indicated that gold(III) could be eventually reduced to gold(I) during the process. As a result of these investigations, a π activation or an oxidative mechanism are most probable for the alkynylation reaction.
- Brand, Jonathan P.,Chevalley, Clara,Scopelliti, Rosario,Waser, Jerome
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p. 5655 - 5666
(2012/06/01)
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- Direct palladium-catalyzed C-3 alkynylation of indoles
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The direct palladium-catalyzed coupling reaction of indoles with alkynyl bromides was described in this paper. In the presence of catalytic amount of PdCl2(PPh3)2 and 2.0 equiv. NaOAc, the coupling reaction of indoles with
- Gu, Yonghong,Wang, Xue-min
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experimental part
p. 763 - 766
(2009/05/07)
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- SYNTHESIS AND CERTAIN PROPERTIES OF ACETYLENYLINDOLES
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A group of new acetylenic derivatives of indole was synthesized by condensation of 2- and 3-iodoindoles with terminal acetylenes. 3-Iodoindole unsubstituted at the heteroatom is distinguished by an increased tendency to undergo deiodination under the reac
- Prikhod'ko, T. A.,Kurilenko, V. M.,Khlienko, Zh. N.,Vasilevskii, S. F.,Shvartsberg, M. S.
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p. 120 - 127
(2007/10/02)
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- SYNTHESIS OF INDOLE ANALOGS OF TOLAN
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A method for the preparation of indole analogs of tolan, viz., indolylphenylacetylene and diindolylacetylene, from indolyl benzyl ketone and indolyl skatyl ketone, respectively, by reaction with a Vilsmeier-Haack reagent was developed.The synthesis of ind
- Kamenskii, A. B.,Smushkevich, Yu. I.,Livshits, A. I.,Suvorov, N. N.
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p. 741 - 743
(2007/10/02)
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