-

Umbreit,M.A.,Sharpless,K.B.

, p. 5526 - 5528 (1977)

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Quinn

, p. 389 (1964)

Rearrangement of α-pinene oxide to campholenic aldehyde over the trimesate metal-organic frameworks MIL-100, MIL-110 and MIL-96

Timofeeva, Maria N.,Panchenko, Valentina N.,Abel, Anna A.,Khan, Nazmul Abedin,Ahmed, Imteaz,Ayupov, Artem B.,Volcho, Konstantin P.,Jhung, Sung Hwa

, p. 114 - 120 (2014)

The catalytic performance of porous metal-benzenetricarboxylates, such as MIL-100(Al, Fe and Cr), MIL-110(Al) and MIL-96(Al), was investigated with a combination of physicochemical and catalytic approaches in the rearrangement of α-pinene oxide to campholenic aldehyde (CA). The investigation of Lewis acidity was done by EPR and IR spectroscopy using 2,2′,6,6′- tetramethyl-1-piperidinyoxyl radical and benzonitrile as the probe molecules, respectively. For Al-BTCs, both these methods showed a decrease in the amount of Lewis acid sites as follows: MIL-100 > MIL-110 > MIL-96. The reaction rate and selectivity toward CA also decreased in the same order. A relatively good correlation between selectivity toward CA and the electronegativity of the metal ion was found for isostructural MIL-100(Al, Fe and Cr). The selectivity toward CA decreased in the order: MIL-100(Al) > MIL-100(Fe) > MIL-100(Cr). The high selectivity toward CA in the presence of MIL-100 has been suggested to originate from the unique structure of this material, which favors shape selectivity.

Acid/vanadium-containing saponite for the conversion of propene into coke: Potential flame-retardant filler for nanocomposite materials

Ostinelli, Luca,Recchia, Sandro,Bisio, Chiara,Carniato, Fabio,Marchese, Leonardo,Guidotti, Matteo,Psaro, Rinaldo

, p. 2394 - 2402,9 (2012)

Vanadium-containing saponite samples were synthesized in a one-pot synthetic procedure with the aim of preparing samples for potential application as fillers for polymeric composites. These vanadium-modified materials were prepared from an acid support by adopting a synthetic strategy that allowed us to introduce isolated structural V species (H/V-SAP). The physicochemical properties of these materials were investigated by XRD analysis and by DR-UV/Vis and FTIR spectroscopy of CO that was adsorbed at 100 K; these data were compared to those of a V-modified saponite material that did not contain any Bronsted acid sites (Na/V-SAP). The surface-acid properties of both samples (together with the fully acidic H-SAP material and the Na-SAP solid) were studied in the catalytic isomerization of α-pinene oxide. The V-containing solids were tested in the oxidative dehydrogenation reaction of propene to evaluate their potential use as flame-retardant fillers for polymer composites. The effect of tuning the presence of Lewis/Bronsted acid sites was carefully studied. The V-containing saponite sample that contained a marked presence of Bronsted acid sites showed the most interesting performance in the oxidative dehydrogenation (ODH) reactions because they produced coke, even at 773 K. The catalytic data presented herein indicate that the H/V-SAP material is potentially active as a flame-retardant filler. In questo lavoro e stato sintetizzata tramite metodologia one-pot una saponite contenente in struttura vanadio, di interesse come additivo per compositi polimerici. La metodologia di sintesi adottata ha permesso di ottenere un solido acido contenente siti di vanadio strutturale isolati (H/V-SAP). Le proprieta chimico-fisiche di tale materiale sono state studiate tramite XRD, DR-UV-Vis e FT-IR di CO adsorbito a 100 K e confrontate con quelle di una V-saponite priva di acidita di Bronsted (Na/V-SAP). Le proprieta acide di entrambi i materiali (e di saponiti acidi H-SAP e sodica Na-SAP) sono state investigate sottoponendo i campioni ad un test catalitico di isomerizzazione dell' ossido di α-pinene. I campioni contenenti vanadio sono stati infine testati come catalizzatori per la reazione di deidrogenazione ossidativa del propene, con l'obiettivo di valutarne i loro potenziale uso come additivi ritardanti di fiamma per compositi polimerici. La saponite contenente vanadio strutturale e caratterizzata da una marcata acidita di Bronsted ha mostrato le migliori prestazioni catalitiche, producendo prodotti carboniosi anche ad alte temperature di esercizio (773 K). I dati catalitici qui mostrati indicano che il campione H/V-SAP e potenzialmente attivo come ritardante di fiamma per compositi polimerici. A hard day's saponite: An acid/vanadium-containing saponite (H/V-SAP) was synthesized and its physicochemical properties were compared to those of a V-modified saponite material that did not contain acid sites. Both samples were tested in the oxidative dehydrogenation (ODH) reaction of propene to study the capability of the samples to form coke species. H/V-SAP was the most interesting catalyst for the production of coke. Copyright

Homo- and heterogeneous α-pinene photooxidation using a protoporphyrin-derived amide

Trytek, Mariusz,Lipke, Agnieszka,Majdan, Marek,Pisarek, Sabina,Gryko, Dorota

, p. 1653 - 1658 (2013)

6,7-Bis[3-(NIμ-tert-butyloxycarbonyllysine methyl ester)]-1,3,5,8-tetramethyl-2,4-divinylporphyrin (3) was synthesized and successfully immobilized in a silica matrix by a sol-gel method. Protoporphyrin (PP)-derived amide 3 showed much higher photostability than its parent PP-IX. Its UV/Vis absorption, excitation, and fluorescence spectra as well as its ability to generate 1O2 were measured both in solution and in the matrix. Subsequently, free and immobilized porphyrins 3 were used as sensitizers in the photooxidation of α-pinene, and their photocatalytic properties were compared. Newly synthesized protoporphyrin (PP)-derived amide 3 is more photostable than PP-IX. Because it is able to generate 1O2, it could be used as a biomimetic catalyst for the oxidation of α-pinene under visible light. After successful immobilization in a silica matrix, a transparent organic-inorganic hybrid was obtained that shows intensive luminescence. Copyright

Katalytische Umlagerungen von α-Pinen-epoxid in Gegenwart von Aluminium-alkoxiden

Scheidl, Franz

, p. 728 (1982)

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TERPENOIDS FROM THE FRENCH LIVERWORT TARGIONIA HYPOPHYLLA

Asakawa, Yoshinori,Toyota, Masao,Cheminat, Annie

, p. 2555 - 2556 (1986)

Key Word Index - Targionia hypophylla; Targioniaceae; Hepaticae; cis- and trans-pinocarveyl acetates; mono-, sesqui- and diterpenoids.Two monoterpene acetates, cis- and trans-pinocarveyl acetates, which make up the characteristic aroma of the thalloid liverwort Targionia hypophylla were isolated, together with the previously known sesquiterpene alcohol, drimenol.

Catalytic isomerisation of α-pinene oxide in the presence of ETS-10 supported ferrocenium ions

Bruno, Sofia M.,Gomes, Ana C.,Coelho, Ana C.,Brand?o, Paula,Valente, Anabela A.,Pillinger, Martyn,Gon?alves, Isabel S.

, p. 66 - 71 (2015)

Ferrocenium ions, [Fc]+, have been immobilised in the microporous titanosilicate ETS-10 by ion exchange of Na+/K+ ions under hydrothermal conditions. The resultant hybrid inorganic-organometallic (ETS-10/[Fc]+) material was characterised by elemental analysis, diffuse reflectance UV-Vis spectroscopy, FT-IR spectroscopy, powder X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis. The ETS-10/[Fc]+ sample was tested as a catalyst for the isomerisation of α-pinene oxide (PinOx) at 35 C. With α, α, α-trifluorotoluene (TFT) as solvent, campholenic aldehyde (CPA) was the main product formed in 38% yield at 100% conversion and 30 min reaction. Other reaction products included trans-carveol, iso-pinocamphone and trans-pinocarveol. The same PinOx conversion and CPA yield could be reached within 1 min reaction time by increasing the reaction temperature (to 55 °C) and the Fe:PinOx molar ratio. Other solvents (hexane, CH3CN, toluene) led to poorer results than TFT. Characterisation of the used catalyst, together with an analysis of the catalytic activity of the liquid phase obtained after contact of ETS-10/[Fc]+ with TFT, indicated that the ETS-10/[Fc]+ sample was resistant toward leaching of iron-containing active species. When the recovered solid was reused in a second batch run, catalytic activity was lower than in the first run, while selectivity to CPA was higher.

Phosphonate functionalized carbon spheres as Br?nsted acid catalysts for the valorization of bio-renewable a-pinene oxide totrans-carveol

Advani, Jacky H.,Biradar, Ankush V.,Singh, Amravati S.

, p. 7210 - 7217 (2020/06/04)

Herein, we report a simple route for the synthesis of phosphonate functionalized Br?nsted solid acid carbon spheres as heterogeneous catalyst for the valorization of bio-derived a-pinene oxide. The Br?nsted acidity was generatedviatwo steps; hydrothermal carbonization of sugar to produce carbon microspheres followed by PCl3treatment to form phosphonate functionalized carbon. The presence of phosphonate was confirmed by CP-MAS31P and13C NMR. In addition, the presence of the P-C, O-P-C and HO-P?O bonds of the phosphonate group was confirmed by FT-IR,31P NMR, and XPS. SEM-EDAX analysis revealed the presence of a phosphorus content of ~1.71 wt% on the surface of the catalyst while elemental mapping showed a uniform dispersion of phosphorus over the carbon spheres. The as-synthesized Br?nsted solid acid catalyst was used for the isomerization of a-pinene oxide which gave 100% conversion with 67%trans-carveol selectivity in highly polar basic solvent in 1 h reaction time. Also, the catalyst showed good recyclable activity even after five cycles.

Selective Allylic Oxidation of Terpenic Olefins Using Co-Ag Supported on SiO2 as a Novel, Efficient, and Recyclable Catalyst

Aberkouks, Abderrazak,Mekkaoui, Ayoub Abdelkader,Ait Ali, Mustapha,El Firdoussi, Larbi,El Houssame, Soufiane

, (2020/02/15)

Co-Ag supported on the SiO2 catalyst was synthesized by the sol-gel method and characterized using XRD, FT-IR, TG-DTG, BET, CV, and SEM/EDX analysis. The catalytic performance of the resulting catalyst was examined by the oxidation of mono and sesquiterpenic olefins using hydrogen peroxide and tert-butyl peroxide as oxidant agents. Various parameters such as catalyst amount, temperature, and solvents have been studied. The Co-Ag supported on the SiO2 catalyst showed a high activity, selectivity, and recyclability for the selected oxidation reaction.

Synthesis of bimetallic Zr(Ti)-naphthalendicarboxylate MOFs and their properties as Lewis acid catalysis

Rasero-Almansa, Antonia M.,Iglesias, Marta,Sánchez, Félix

, p. 106790 - 106797 (2016/11/23)

Bimetallic Zr(Ti)-NDC based metal-organic frameworks (MOFs) have been prepared by incorporation of titanium(iv) into zirconium(iv)-NDC-MOFs (UiO family). The resulting materials maintain thermal (up to 500 °C), chemical and structural stability with respect to parent Zr-MOFs as can be deduced from XRD, N2 adsorption, FTIR and thermal analysis. The materials have been studied in Lewis acid catalyzed reactions, such as, domino Meerwein-Ponndorf-Verley (MPV) reduction-etherification of p-methoxybenzaldehyde with butanol, isomerization of α-pinene oxide and cyclization of citronellal.