1197-07-5Relevant articles and documents
Arbuzov,B.A. et al.
, (1965)
Isomerization of α-pinene oxide using Fe-supported catalysts: Selective synthesis of campholenic aldehyde
Stekrova, Martina,Kumar, Narendra,Aho, Atte,Sinev, Ilia,Grünert, Wolfgang,Dahl, Johnny,Roine, Jorma,Arzumanov, Sergey S.,M?ki-Arvela, P?ivi,Murzin, Dmitry Yu.
, p. 162 - 176 (2014)
α-Pinene oxide, an oxygenated derivative of α-pinene, can be converted into various valuable substances useful as flavour, fragrance and pharmaceutical compounds. Campholenic aldehyde is one of the most desired products of α-pinene oxide isomerization being a valuable intermediate for the production of sandalwood-like fragrances. Iron modified zeolites Beta-75 and ZSM-5, mesoporous material MCM-41, silica and alumina were prepared by two methods (impregnation and solid-state ion exchange) and tested for selective preparation of campholenic aldehyde by isomerization of α-pinene oxide. The characterization of tested catalyst was carried out using scanning electron microscope analysis, nitrogen adsorption measurements, pyridine adsorption-desorption with FTIR, X-ray absorption spectroscopy measurements, XPS-analysis, 29Si MAS NMR and 27Al MAS NMR and X-ray diffraction. The isomerization of α-pinene oxide was carried out in toluene as a solvent at 70 C. The main properties influencing the activity and the selectivity are the acidic and structural properties of the tested catalysts. The highest selectivity of 66% was achieved at complete conversion of α-pinene oxide with Fe-MCM-41.
Tailoring Lewis/Br?nsted acid properties of MOF nodesviahydrothermal and solvothermal synthesis: simple approach with exceptional catalytic implications
Bohigues, Benjamin,Boronat, Mercedes,Corma, Avelino,Lopes, Christian W.,Meira, Débora M.,Moliner, Manuel,Rojas-Buzo, Sergio
, p. 10106 - 10115 (2021)
The Lewis/Br?nsted catalytic properties of the Metal-Organic Framework (MOF) nodes can be tuned by simply controlling the solvent employed in the synthetic procedure. In this work, we demonstrate that Hf-MOF-808 can be prepared from a material with a higher amount of Br?nsted acid sites,viamodulated hydrothermal synthesis, to a material with a higher proportion of unsaturated Hf Lewis acid sites,viamodulated solvothermal synthesis. The Lewis/Br?nsted acid properties of the resultant metallic clusters have been studied by different characterization techniques, including XAS, FTIR and NMR spectroscopies, combined with a DFT study. The different nature of the Hf-MOF-808 materials allows their application as selective catalysts in different target reactions requiring Lewis, Br?nsted or Lewis-Br?nsted acid pairs.
Heteropoly acid catalysts in upgrading of biorenewables: Synthesis of para-menthenic fragrance compounds from α-pinene oxide
Ribeiro, Cláudio J.A.,Pereira, Matheus M.,Kozhevnikova, Elena F.,Kozhevnikov, Ivan V.,Gusevskaya, Elena V.,da Silva Rocha, Kelly A.
, p. 166 - 170 (2020)
The isomerization of α-pinene oxide in the presence of Cs2.5H0.5PW12O40 (CsPW) heteropolysalt as solid acid catalyst is reported. The reactions were performed in various solvents, which allowed to obtain trans-carveol, trans-sobrerol and pinol in 60–80% yield each, which exceed the yields reported so far. The CsPW catalyst could be recovered and reused without loss of its activity and selectivity.
Chiral Imidazo[1,5- a]pyridine-Oxazolines: A Versatile Family of NHC Ligands for the Highly Enantioselective Hydrosilylation of Ketones
Chinna Ayya Swamy,Varenikov, Andrii,Ruiter, Graham De
supporting information, p. 247 - 257 (2020/02/04)
Herein we report the synthesis and application of a versatile class of N-heterocyclic carbene ligands based on an imidazo[1,5-a]pyridine-3-ylidine backbone that is fused to a chiral oxazoline auxiliary. The key step in the synthesis of these ligands involves the installation of the oxazoline functionality via a microwave-assisted condensation of a cyano-azolium salt with a wide variety of 2-amino alcohols. The resulting chiral bidentate NHC-oxazoline ligands form stable complexes with rhodium(I) that are efficient catalysts for the enantioselective hydrosilylation of structurally diverse ketones. The corresponding secondary alcohols are isolated in good yields (typically >90%) with good to excellent enantioselectivities (80-93% ee). The reported hydrosilylation occurs at ambient temperatures (40 °C), with excellent functional group tolerability. Even ketones bearing heterocyclic substituents (e.g., pyridine or thiophene) or complex organic architectures are hydrosilylated efficiently, which is discussed further in this report.
