13225-61-1Relevant articles and documents
Alumina-Mediated π-Activation of Alkynes
Akhmetov, Vladimir,Amsharov, Konstantin,Feofanov, Mikhail,Sharapa, Dmitry I.
supporting information, p. 15420 - 15426 (2021/09/30)
The ability to induce powerful atom-economic transformation of alkynes is the key feature of carbophilic π-Lewis acids such as gold- and platinum-based catalysts. The unique catalytic activity of these compounds in electrophilic activations of alkynes is explained through relativistic effects, enabling efficient orbital overlapping with π-systems. For this reason, it is believed that noble metals are indispensable components in the catalysis of such reactions. In this study, we report that thermally activated γ-Al2O3activates enynes, diynes, and arene-ynes in a manner enabling reactions that were typically assigned to the softest π-Lewis acids, while some were known to be triggered exclusively by gold catalysts. We demonstrate the scope of these transformations and suggest a qualitative explanation of this phenomenon based on the Dewar-Chatt-Duncanson model confirmed by density functional theory calculations.
Copper-Mediated Nucleophilic Addition/Cascade Cyclization of Aryl Diynes
Sinclair, Geoffrey S.,Yang, Tianyu,Wang, Sunmeng,Chen, Wei H.,Schipper, Derek J.
supporting information, p. 802 - 805 (2017/03/01)
Treatment of diyne substrates with sulfinate salts under the action of copper(II) triflate results in a cascade cyclization reaction. The reaction involves nucleophilic addition of the sulfinate and formation of two new C-C bonds with concomitant cleavage of an aryl C-H bond. The reaction proceeds in good yields with a range of diyne precursors and sulfinate salts. Preliminary mechanistic analysis reveals a rare example of an operative ionic mechanism in contrast to other related cyclizations.
A Ruthenium Complex-Catalyzed Cyclotrimerization of Halodiynes with Nitriles. Synthesis of 2- and 3-Halopyridines
Bedná?ová, Eva,Colacino, Evelina,Lamaty, Frédéric,Kotora, Martin
supporting information, p. 1916 - 1923 (2016/07/06)
Monohalo- and dihalodiynes efficiently undergo [2+2+2] cyclotrimerization with nitriles in the presence of a catalytic amount of the ruthenium complex Cp*RuCl(cod) (10 mol%) to afford the corresponding halopyridines under ambient conditions in good isolated yields (up to 90%). The halopyridines are formed as two separable regioisomers. This is the first example of a direct synthesis of halopyridines from haloalkynes and nitriles. (Figure presented.) .
Phosphine-promoted cyclization of dicyclopropenones
Yang, Jin-Ming,Tang, Xiang-Ying,Wei, Yin,Shi, Min
, p. 3545 - 3552 (2014/01/06)
A novel phosphine-promoted intramolecular cyclization of dicyclopropenones 1 has been described in this contribution. A variety of 2,3-dihydro-1H-indene-4, 6-diol derivatives 2 and hexahydropentalen-2-one derivatives 3 were obtained selectively in moderat
Bifunctional (cyclopentadienone)iron-tricarbonyl complexes: Synthesis, computational studies and application in reductive amination
Moulin, Solenne,Dentel, Helene,Pagnoux-Ozherelyeva, Anastassiya,Gaillard, Sylvain,Poater, Albert,Cavallo, Luigi,Lohier, Jean-Francois,Renaud, Jean-Luc
supporting information, p. 17881 - 17890 (2014/01/17)
Reductive amination under hydrogen pressure is a valuable process in organic chemistry to access amine derivatives from aldehydes or ketones. Knoelker's complex has been shown to be an efficient iron catalyst in this reaction. To determine the influence of the substituents on the cyclopentadienone ancillary ligand, a series of modified Knoelker's complexes was synthesised and fully characterised. These complexes were also transformed into their analogous acetonitrile iron-dicarbonyl complexes. Catalytic activities of these complexes were evaluated and compared in a model reaction. The scope of this reaction is also reported. For mechanistic insights, deuterium-labelling experiments and DFT calculations were undertaken and are also presented. Festival of amination: Two series of modified Knoelker's complexes were synthesised and applied in the reductive amination of various carbonyl derivatives with primary or secondary amines (see scheme, TIPS = triisopropylsilyl). For a mechanistic insight, deuterium-labelling experiments and DFT calculations were undertaken and are also presented. Copyright
Electrophilic chemistry of propargylic alcohols in imidazolium ionic liquids: Propargylation of arenes and synthesis of propargylic ethers catalyzed by metallic triflates [Bi(OTf)3, Sc(OTf)3, Yb(OTf) 3], TfOH, or B(C6F5)3
Aridoss, Gopalakrishnan,Sarca, Viorel D.,Ponder Jr, James F.,Crowe, Jessica,Laali, Kenneth K.
experimental part, p. 2518 - 2529 (2011/05/13)
Metallic triflates M(OTf)3 (M = Bi, Sc, Yb), immobilized in imidazolium ionic liquids [BMIM][BF4], [BMIM][PF6] and [BMIM][OTf] are efficient systems for one-pot reactions of propargylic alcohols 1,3-diphenyl-2-propyn-1-ol Ia, 1-methyl-3-phenyl-2-propyn-1-ol Ib, and 2-pentyn-1-ol Ic, with a wide range of arenes bearing activating substituents, under mild conditions. The [BMIM][PF6]/B(C6F 5)3 and [BMIM][PF6]/TfOH systems were superior in propargylation with Ib and Ic, while reaction of 3-phenyl-2-propyn-1-ol Id with activated aromatics resulted in the formation of diaryl-propanones instead. Propargylation of anisole with Ib under M(OTf)3 catalysis is highly para selective, but with TfOH or B(C6F5)3 as catalyst the ortho isomer was also formed. Steric influence of the propargylic moiety on substrate selectivity is reflected in the lack of ortho propargylation for phenol and ethylbenzene by using propargylic alcohol Ia, and notable formation of the ortho isomer employing alcohol Ib. In the later case para selectivity could be increased by running the reaction at r. t. for 10 h. The Bi(OTf)3-catalyzed reaction of 1,3-dimethoxybenzene with Ia led to minor formation of dipropargylated derivative, along with the monopropargyl product. Propargylation of the less reactive arenes (mesitylene, ethylbenzene, toluene), using Sc(OTf)3 as catalyst, led increasingly to the formation of dipropargylic ethers and propargyl ketones, with no ring propargylation product with toluene. Concomitant formation of dipropargylic ether was also observed in Yb(OTf)3-catalyzed propargylation of β-naphthol, whereas propargylation of 2-nitro and 4-nitro-aniline led to N-propargylation. The recycling/reuse of the IL was demonstrated in representative cases with no appreciable decrease in the conversions over 3 cycles. It was also shown that recycled IL could be used to propargylate a different aromatic compound. The efficacy of IL/M(OTf)3 and IL/TfOH systems for cross-breeding two propargylic alcohols or a propargylic alcohol with a non-propargylic alcohol and/or self-coupling, to form a wide variety of functionalized ethers is also demonstrated.
(Cyclopentadienone)iron shvo complexes: Synthesis and applications to hydrogen transfer reactions
Johnson, Tarn C.,Clarkson, Guy J.,Wills, Martin
, p. 1859 - 1868 (2011/05/14)
A series of (cyclopendienone)iron tricarbonyl complexes were prepared using an intramolecular cyclization strategy. These were applied to the catalysis of the oxidation of alcohols to aldehydes and ketones. When paraformaldehyde was used as the hydrogen acceptor, formate esters were obtained as coproducts and, in several cases, the major products.
Iridium- and rhodium-catalyzed [2+2+2] cycloadditions of diynes with maleimide: A new synthetic route to highly substituted phthalimides
Alvarez, Leonardo X.,Bessières, Bernard,Einhorn, Jacques
experimental part, p. 1376 - 1380 (2009/04/06)
The [2+2+2] cycloaddition of maleimide with α,ω-diynes in the presence of [IrCl(cod)]2 or [RhCl(cod)]2 and DPPE gives cyclohexadiene derivatives which are readily aromatized with DDQ or MnO 2. This two-step procedure gives
Intramolecular anionic Diels-Alder reactions of 1-aryl-4-oxahepta-1,6-diyne systems in DMSO
Kudoh, Takayuki,Mori, Tomoko,Shirahama, Mitsuhito,Yamada, Masashi,Ishikawa, Teruhiko,Saito, Seiki,Kobayashi, Hisayoshi
, p. 4939 - 4947 (2008/02/03)
Base-promoted cycloaddition reactions of 1-aryl- or 1-aryl-7-substituted-4- oxahepta-1,6-diyne systems in DMSO have proven to involve an anionic intramolecular Diels-Alder process taking place even at room temperature in spite of the reaction suffering from temporary disruption of aromaticity. Although initially formed α-arylallenide anion can be protonated by DMSO, it can be back to the allenide anion probably because of a small acidity difference between α-arylallene and DMSO. The α-arylallenide anion in combination with the α-aryl substituent can constitute an anionic diene structure that undergoes the intramolecular Diels-Alder reaction involving the C(6)-yne part, a very fast process probably because of the increased HOMO-1 level of the anionic diene, as shown by DFT calculations. Diversified substituted naphthalenes, benzofurans, phenanthrenes, and quinolines, including biaryl architectures, are available from 4-oxahepta-1,6-diynes in a highly expeditious way.