825-25-2

Usage

Uses

Used in Pharmaceutical Industry:
2-Cyclopentylidenecyclopent-2-enone is used as a key intermediate in the synthesis of peptidase IV inhibitors, which are important for the treatment of type 2 diabetes. Its unique structure allows for the development of novel therapeutic agents that can effectively manage blood sugar levels in diabetic patients.
Used in Organic Synthesis:
2-Cyclopentylidenecyclopent-2-enone is also used as a building block in the synthesis of various simple and complex organic compounds. Its versatile structure makes it a valuable component in the creation of new molecules with potential applications in various industries, such as pharmaceuticals, agrochemicals, and materials science.

InChI:InChI=1/C10H14O/c11-10-7-3-6-9(10)8-4-1-2-5-8/h1-7H2

Upstream product

• 110-89-4 piperidine 
• 120-92-3 cyclopentanone 
• 13388-94-8 spiro[4.5]decan-6-one 
• 141-52-6 sodium ethanolate 
• 141-97-9 ethyl acetoacetate 
• 18850-78-7 calcium monohydrate adipate 
• 60-29-7 diethyl ether 
• 677-22-5 tert-butylmagnesium chloride 
• 16424-32-1 2-Buthylidenecyclopentenone 
• 631-61-8 ammonium acetate 
• 1003-03-8 Cyclopentamine 
• 17522-30-4 Cyclodec-5-ynone 
• 50555-86-7 4-aza-9-diazo-9H-fluorene 
• 137265-69-1 2-(4'-Iodobutyl)-3-tributylstannylcyclohex-2-enone 

Downstream Products

• 24071-97-4 5-Cyclopentyl-5-oxo-valeriansaeure-aethylester 
• 97790-43-7 1-Phenyl-2--cyclopenten-(1) 
• 934-02-1 bicyclopentyl-1,1'-diene 
• 98470-84-9 1-Benzyl-2--cyclopenten-(1) 
• 74542-37-3 1-<1-(5-Oxo-1-Cyclopentenyl)cyclopentyl>-4-phenyl-1,2,4-triazolidine-3,5-dione 
• 74542-36-2 1-<1-(1-Cyclopentenyl)-2-oxocyclopentyl>-4-phenyl-1,2,4-triazolidine-3,5-dione 
• 85554-06-9 2-cyclopent-1-enyl-2-<2-(phenylsulfinyl)-1-ethyl>cyclopentanone 
• 104703-62-0 (E)-trisylhydrazone de la cyclopentylidene-2 cyclopentanone-1 
• 542-28-9 3,4,5,6-tetrahydro-2H-pyran-2-one 
• 2866-71-9 (1,1'-bicyclopentyl)-2-one 
• 117712-77-3 (1'S,1''S)-[1,2';1',1'';2'',1''']Quatercyclopentane-1',1''-diol 
• 103225-42-9 1,1'-Difluoro-bicyclopentyl-2-one 
• 94041-91-5 2-(1-cyclopentenyl)-2-cinnamylcyclopentanone 
• 22354-35-4 2-cyclopentylcyclopent-2-en-1-one 

Relevant academic research and scientific papers

Diatomite Stabilized KOH: An Efficient Heterogeneous Catalyst for Cyclopentanone Self-condensation

Aldol condensation of cyclopentanone is an attractive reaction for bio-jet fuel production. KOH is an efficient homogeneous catalyst for aldol condensation but suffering the problem of separation. In this paper, a heterogeneous catalyst, diatomite stabilized KOH (KOH/diatomite) was prepared in a simple way (dry-mixed impregnation process), and exhibited good activity (overall yield: 85.0 %) and reusability. To clarify the support effect of diatomite, KOH/SiO2 catalyst was also prepared. According to characterizations of these two catalysts, we suggest that the excellent catalytic activity of KOH/diatomite can be attributed to the formation of K?O?Si bond. In addition, the impurity elements existed in diatomite (e. g. CaO, Na2O, Al2O3) and higher BET surface areas may also benefit to this reaction. This study provides a new possibility for converting homogeneous catalyst (KOH) to heterogeneous catalyst (KOH/diatomite). In this way, KOH/diatomite performed excellent catalytic activity and exhibited stable reusability, which can avoid the problem of separation and pollution.

Fine-Bubble-Slug-Flow Hydrogenation of Multiple Bonds and Phenols

We describe a promising method for the continuous hydrogenation of alkenes or alkynes by using a newly developed fine-bubble generator. The fine-bubble-containing slug-flow system was up to 1.4 times more efficient than a conventional slug-flow method. When applied in the hydrogenation of phenols to the corresponding cyclohexanones, the fine bubble-slug-flow method suppressed over-reduction. As this method does not require the use of excess gas, it is expected to be widely applicable in improving the efficiency of gas-mediated flow reactions.

Highly efficient Nb2O5 catalyst for aldol condensation of biomass-derived carbonyl molecules to fuel precursors

Aldol condensation is of significant importance for the production of fuel precursors from biomass-derived chemicals and has received increasing attention. Here we report a Nb2O5 catalyst with excellent activity and stability in the aldol condensation of biomass-derived carbonyl molecules. It is found that in the aldol condensation of furfural with 4-heptanone, Nb2O5 has obviously superior activity, which is not only better than that of other common solid acid catalysts (ZrO2 and Al2O3), more importantly, but also better than that of solid base catalysts (MgO, CaO, and magnesium-aluminum hydrotalcite). The detailed characterizations by N2 sorption/desorption, NH3-TPD, Py-FTIR and DRIFTS study of acetone adsorption reveal that Nb2O5 has a strong ability to activate the C=O bond in carbonyl molecules, which helps to generate a metal enolate intermediate and undergo the nucleophilic addition to form a new C–C bond. Furthermore, the applicability of Nb2O5 to aldol condensation is extended to other biomass-derived carbonyl molecules and high yields of target fuel precursors are obtained. Finally, a multifunctional Pd/Nb2O5 catalyst is prepared and successfully used in the one-pot synthesis of liquid alkanes from biomass-derived carbonyl molecules by combining the aldol condensation with the sequential hydrodeoxygenation.

Synthesis of Unsaturated Spiroacetals, Cyclopentanone Derivatives, in the Presence of Natural Aluminosilicate Modified with Zirconium Cations

Abstract: Conditions for the condensation of cyclopentanone and n-valeric aldehyde to 2-pentylidenecyclopentanone in the presence of an alcoholic solution of piperidine have been developed. The isomerization of the latter in a continuous-flow system over γ-Al2O3 yields 2-pentylcyclopent-2-en-1-one. The condensation of the obtained unsaturated ketones with ethane-1,2-diol in the presence of a heterogeneous catalyst, a natural aluminosilicate (perlite) modified with zirconyl sulfate, has been studied. The optimum conditions for the preparation of the corresponding unsaturated spiroacetals have been found. The synthesized compounds can be used as synthetic fragrances for different purposes.

Morphology-Tuned Activity of Ru/Nb2O5 Catalysts for Ketone Reductive Amination

Amines are important compounds in natural products and medicines. Specifically, cyclopentylamine is one of the value-added chemicals widely used in the production of pesticides, cosmetics and medicines. In this work, three Ru/Nb2O5 catalysts with different Nb2O5 morphologies were used in the reductive amination of cyclopentanone under mild reaction conditions (90 °C, 2 MPa H2), among which 1 %Ru/Nb2O5?L catalyst exhibits best performance with the yield of cyclopentylamine reaching 84 %. This catalytic system is stable and has not significant deactivation even after 5 runs in the durability test. In addition, this catalyst can be extended to a series of aldehydes/ketones. Further comprehensive characterizations (XPS analysis and CO-adsorption DRIFT) reveal that the electronic effect of Ru species can be ruled out; instead, the activity of the catalyst is strongly influenced by the geometric effect. Layered Nb2O5 material possesses the highest surface area, resulting in the highest Ru dispersion, and therefore shows the highest catalytic activity. The in-situ DRIFT-MS technique was also used to reveal and understand the reaction mechanism. It is found that Ru species play a key role in activating carbonyl groups. This study illustrates a promising application of Ru/Nb2O5-Layer catalyst in the synthesis of amine and provides an understanding to the reaction mechanism.

Thermal Degradation of Aviation Synthetic Lubricating Base Oil

The thermal degradation, under oxidative pyrolysis conditions, of two synthetic lubricating base oils, poly-α-olefin (PAO) and di-ester (DE), was investigated. The main objective of the study was to characterize their behavior in simulated “areo-engine” conditions, i.e. compared the thermal stability and identified the products of thermal decomposition as a function of exposure temperature. Detailed characterizations of products were performed with Fourier transform infrared spectrometry (FTIR), gas chromatography/ mass spectrometry (GC/MS), viscosity experiments and four-ball tests. The results showed that PAO had the lower thermal stability, being degraded at 200°C different from 300°C for DE. The degradation also effected the tribological properties of lubricating oil. Several by-products were identified during the thermal degradation of two lubricants. The majority of PAO products consisted of alkanes and olefins, while more oxygen-containing organic compounds were detected in DE samples according to the observation of GC/MS analysis. The related reaction mechanisms were discussed according to the experimental results.

Simultaneous Upgrading of Furanics and Phenolics through Hydroxyalkylation/Aldol Condensation Reactions

The simultaneous conversion of cyclopentanone and m-cresol has been investigated on a series of solid-acid catalysts. Both compounds are representative of biomass-derived streams. Cyclopentanone can be readily obtained from sugar-derived furfurals through Piancatelli rearrangement under reducing conditions. Cresol represents a family of phenolic compounds, typically obtained from the depolymerization of lignin. In the first biomass conversion strategy proposed here, furfural is converted in high yields and selectivity to cyclopentanone (CPO) over metal catalysts such as Pd-Fe/SiO2 at 600 psi (～4.14 MPa) H2 and 150 °C. Subsequently, CPO and cresol are further converted through acid-catalyzed hydroxyalkylation. This C?C coupling reaction may be used to generate products in the molecular weight range that is appropriate for transportation fuels. As molecules beyond this range may be undesirable for fuel production, a catalyst with a suitable porous structure may be advantageous for controlling the product distribution in the desirable range. If Amberlyst resins were used as a catalyst, C12–C24 products were obtained whereas when zeolites with smaller pore sizes were used, they selectively produced C10 products. Alternatively, CPO can undergo the acid-catalyzed self-aldol condensation to form C10 bicyclic adducts. As an illustration of the potential for practical implementation of this strategy for biofuel production, the long-chain oxygenates obtained from hydroxyalkylation/aldol condensation were successfully upgraded through hydrodeoxygenation to a mixture of linear alkanes and saturated cyclic hydrocarbons, which in practice would be direct drop-in components for transportation fuels. Aqueous acidic environments, which are typically encountered during the liquid-phase upgrading of bio-oils, would inhibit the efficiency of base-catalyzed processes. Therefore, the proposed acid-catalyzed upgrading strategy is advantageous for biomass conversion in terms of process simplicity.

Controllable self-aldol condensation of cyclopentanone over MgO-ZrO2 mixed oxides: Origin of activity & selectivity

Mesoporous MgO-ZrO2 mixed oxides with different Mg/Zr ratios have been synthesized by a coprecipitation method and employed to catalyze self-aldol condensation of cyclopentanone in a solvent-free condition under atmospheric pressure. Effects of temperature, reaction time, catalyst amount and Mg/Zr ratio on the reaction have been investigated. Remarkable raise in catalytic activity and selectivity has been found on MgO-ZrO2 mixed oxides as compared with pure MgO or ZrO2. Characterization including XRD, XPS, BET and CO2- TPD has been carried out to figure out the relationship between catalyst properties and their catalytic activity.

Direct conversion of carboxylic acids (Cn) to alkenes (C2n - 1) over titanium oxide in absence of noble metals

Carbon-carbon bond formations and deoxygenation reactions are important for biomass up-grading. The classical ketonic decarboxylation of carboxylic acids provides symmetrical ketones with 2n + 1 carbon atoms and eliminates three oxygen atoms. Herein, this reaction is carried out with titanium oxide at 400°C, and an olefin with 2n + 1 carbon atoms is obtained instead of the ketone. For olefin formation hydrogen transfer reactions are required from suitable precursors to form aromatics and coke. Additional aldol condensation reactions increase further molecular weight in the product mixture. Hence, a combination of titanium oxide with a hydrodeoxygenation bed provides double amount of diesel fuel as the combination with zirconium oxide when reacting hexose-derived pentanoic acid.

Base-promoted ring expansion of 3-aminopyrimidine-2-thiones into 1,2,4-triazepine-3-thiones

A base-promoted ring expansion of 3-amino-4-hydroxyhexahydropyrimidine-2-thiones into 2,4,5,6-tetrahydro-3H-1,2,4-triazepine-3-thiones has been developed. Experimental data and DFT calculations showed that the reaction proceeded through fast formation of intermediate acyclic isomers of pyrimidines followed by their slow cyclization into triazepines. The starting hydroxypyrimidines were prepared by reaction of α,β-unsaturated ketones or β-alkoxy ketones with HNCS followed by treatment of the obtained β-isothiocyanato ketones with hydrazine. Triazepine-3-thiones were transformed into their 3-oxo analogs by oxidation with H2O2 under basic conditions.