Ruthenium-catalyzed [2 + 2+ 2] cycloaddition of three different alkynes

Ura, Yasuyuki; Sato, Yoshitaka; Tsujita, Hiroshi; Kondo, Teruyuki; Imachi, Misako; Mitsudo, Take‐aki

doi:10.1016/j.molcata.2005.06.009

Cited by 34 publications

(12 citation statements)

References 17 publications

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“…However, such transformations have been accomplished in only a few examples because of the difficulty in achieving high chemo‐ and regioselectivities. For examples of the cross‐cyclotrimerization of three different alkynes,2 Ikeda and co‐workers reported a nickel‐catalyzed reaction2a and Kondoh and co‐workers reported a ruthenium‐catalyzed reaction 2b. For examples of the cross‐cyclotrimerization of two different alkynes with alkenes,3–10 Ikeda and co‐workers reported the nickel‐catalyzed reaction3 and Obora and co‐workers reported the niobium‐catalyzed reaction 4.…”

Section: Methodsmentioning

confidence: 99%

Carbon‐Nanotubes‐Supported Pd Nanoparticles for Alcohol Oxidations in Fuel Cells: Effect of Number of Nanotube Walls on Activity

Zhang

Xiang

et al. 2015

ChemSusChem

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Carbon nanotubes (CNTs) are well known electrocatalyst supports due to their high electrical conductivity, structural stability, and high surface area. Here, we demonstrate that the number of inner tubes or walls of CNTs also have a significant promotion effect on the activity of supported Pd nanoparticles (NPs) for alcohol oxidation reactions of direct alcohol fuel cells (DAFCs). Pd NPs with similar particle size (2.1-2.8 nm) were uniformly assembled on CNTs with different number of walls. The results indicate that Pd NPs supported on triple-walled CNTs (TWNTs) have the highest mass activity and stability for methanol, ethanol, and ethylene glycol oxidation reactions, as compared to Pd NPs supported on single-walled and multi-walled CNTs. Such a specific promotion effect of TWNTs on the electrocatalytic activity of Pd NPs is not related to the contribution of metal impurities in CNTs, oxygen-functional groups of CNTs or surface area of CNTs and Pd NPs. A facile charge transfer mechanism via electron tunneling between the outer wall and inner tubes of CNTs under electrochemical driving force is proposed for the significant promotion effect of TWNTs for the alcohol oxidation reactions in alkaline solutions.

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Section: Methodsmentioning

confidence: 99%

Carbon‐Nanotubes‐Supported Pd Nanoparticles for Alcohol Oxidations in Fuel Cells: Effect of Number of Nanotube Walls on Activity

Zhang

Xiang

et al. 2015

ChemSusChem

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“…In the course of our continuous investigations, we found that the same ruthenium catalyst, Cp*RuCl(cod), could be applied to the three-component coupling reaction and successfully achieved the chemoselective [2+2+2] cocyclization of three different alkynes, by controlling the molar ratio of the substrates. 42 The reaction of DMAD (2g, 1.0 equivalent), 1-decyne (11b, 6.0 equivalents), and 3-hexyne (2h, 40 equivalents) was carried out in toluene under reflux for 24 h in the presence of a catalytic amount (5.0 mol%) of Cp*RuCl(cod) to give a single regioisomer of three-component coupling products, dimethyl 3,4-diethyl-5-n-octyl-o-phthalate (14b) in 57% yield based on 2g. The only byproduct is 5,6-diethyl-1,2,3,4-benzenetetracarboxylate (<20%).…”

Section: Scheme 8 Ru-catalyzed Synthesis Of O-phthalates By Intermolecular [2+2+2] Cycloaddition Of Terminal Alkynes and Dmadmentioning

confidence: 99%

On Inventing Catalytic Reactions via Ruthena- or Rhodacyclic Intermediates for Atom Economy

Kondo¹

2008

Synlett

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Novel catalytic reactions via ruthena-or rhodacyclic intermediates have been developed by our research group. We initiated our study from (1) ruthenium-catalyzed [2+2] cycloaddition of alkynes with alkenes, followed by developing (2) intramolecular Pauson-Khand-type reaction of 1,6-enynes, (3) hydroquinone synthesis, (4) cyclocotrimerization reactions, and (5) codimerization of styrenes with ethylene. Another approach to construct novel functional monomers, such as cyclopentenones, pyranopyrandiones, and substituted phenols, involves cleavage of carbon-carbon bonds in cyclobutenediones, cyclopropenones, and cyclobutenones. All reactions may proceed with high atom-efficiency via ruthena-or rhodacyclic intermediates, represented by ruthenacyclopentene, (maleoyl)ruthenium, and rhodacyclopentenone intermediates. In addition, rhodium-catalyzed [2+2+2] cocyclization of alkynes with isocyanates as well as novel ruthenium-catalyzed [2+2+1] cocyclization of alkynes, isocyanates, and carbon monoxide have been disclosed. Regio-and Stereoselective Dimerization of Styrenes and Linear Codimerization of Styrenes with Ethylene 3 Ruthenium-and Rhodium-Catalyzed Cleavage of C-C Bonds Leading to Reconstructive Synthesis of Novel Functional Monomers 3.1 Ru-Catalyzed Selective Monodecarbonylative Coupling of Cyclobutenediones with Alkenes to Cyclopentenones 3.2 Ru-Catalyzed Carbonylative Dimerization of Cyclopropenones and Cross-Carbonylation of Cyclopropenones with Alkynes to Pyranopyrandiones 3.3 Ru-and Rh-Catalyzed Ring-Opening Reactions of Cyclobutenones 3.4 Rh-Catalyzed Direct Synthesis of Substituted Phenols from Cyclobutenones and Electron-Deficient Alkenes 4 Ruthenium-and Rhodium-Catalyzed Cocyclization of Alkynes and Isocyanates 4.1 Rh-Catalyzed Cyclocotrimerization of Alkynes and Isocyanates to 2-Pyridones or Pyrimidine-2,4-diones 4.2 Ru-Catalyzed [2+2+1] Cocyclization of Alkynes, Isocyanates, and Carbon Monoxide 5 Summary

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“…A successful solution to minimize the chemo- and regioselectivity problems includes temporary connections of two or three different monoynes with disposable tether groups, such as boron and silyl groups. A practical solution to control both chemo- and regioselectivity in the completely intermolecular cross-cyclotrimerization of alkynes without the use of tether groups is the use of two or three different alkynes possessing different electronic properties. − For example, our research group reported the highly chemo- and regioselective cross-cyclotrimerization of nonactivated terminal alkynes and electron-deficient internal alkynes (dialkyl acetylenedicarboxylates) to produce 3,6-disubstituted phthalates, catalyzed by a cationic rhodium(I)/H 8 -BINAP complex at room temperature (Scheme , top). , This method has been successfully applied to the synthesis of paracyclophanes including cycloparaphenylenes . However, the chemo- and regioselective cross-cyclotrimerization without employing an electronically biased combination of alkynes has not been reported to date.…”

Section: Introductionmentioning

confidence: 99%

Rhodium-Catalyzed Chemo- and Regioselective Intermolecular Cross-Cyclotrimerization of Nonactivated Terminal and Internal Alkynes

2017

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It has been established that a cationic rhodium(I)/BIPHEP complex is able to catalyze the unprecedented intermolecular cross-cyclotrimerization of nonactivated terminal and internal alkynes at room temperature. In this transformation, the use of arylacetylenes as terminal alkynes and 1,4-butynediol derivatives as internal alkynes afforded the cross-cyclotrimerization products with good chemo- and regioselectivity. The present study clearly demonstrated that an electronically biased combination of nonactivated and electron-deficient alkynes is not necessary to realize good chemo- and regioselectivity in the cationic rhodium(I) complex-catalyzed intermolecular cross-cyclotrimerization.

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Ruthenium-catalyzed [2 + 2+ 2] cycloaddition of three different alkynes

Cited by 34 publications

References 17 publications

Carbon‐Nanotubes‐Supported Pd Nanoparticles for Alcohol Oxidations in Fuel Cells: Effect of Number of Nanotube Walls on Activity

Carbon‐Nanotubes‐Supported Pd Nanoparticles for Alcohol Oxidations in Fuel Cells: Effect of Number of Nanotube Walls on Activity

On Inventing Catalytic Reactions via Ruthena- or Rhodacyclic Intermediates for Atom Economy

Rhodium-Catalyzed Chemo- and Regioselective Intermolecular Cross-Cyclotrimerization of Nonactivated Terminal and Internal Alkynes

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