Doctoral theses
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Identifier |
000353150 |
Title |
Μετασχηματισμός πολυενικών τερπενίων και εποξειδίων ετερογενώς καταλυόμενοι από το ζεόλιθο Μ-Υ και από νανοσωματίδια Au/TiO2 |
Alternative Title |
Heterogeneous transformations of polyene terpenes and epoxides catalyzed by zeolite M-Y and gold nanoparticles supported on TiO2 |
Author
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Ράπτης, Χρήστος Νικολάου
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Thesis advisor
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Στρατάκης, Μανώλης
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Abstract |
In the present Thesis, the cycloisomerization of terpenes and epoxy terpenes under heterogeneous conditions was studied, catalyzed by acidic porous materials
such as zeolite HY (Al/Si=1/30) and gold nanoparticles supported on TiO2. The
results can be summarized as follows:
• Zeolite HY (Al/Si=1/30) is an effective and recyclable catalyst for the
cyclization of terpenoids and a promising catalyst for the cyclization of 1,6-dienes .
• The mechanism for the acid-catalyzed cyclization of geranyl acetate and
farnesyl acetate was examined through stereoisotopic studies and β-secondary
isotope effects under homogeneous and heterogeneous conditions. The results are consonant with a concerted mechanism through two competing, boat-like and chair-like, transition states.
• The acidic porous material, MOF Cu3(btc)2 (btc = benzenetricarboxylate),
catalyzes effectively the isomerization of epoxy terpenes in good yield but in low product selectivity.
• Gold nanoparticles supported on TiO2 catalyze the selective isomerization of
epoxides to allylic alcohols. The reaction proceeds in high yields and the product selectivity is often remarkable. It is proposed that the reaction occurs through a concerted mechanism,which includes coordination with the epoxide functionality to the ionic gold species and the simultaneous abstraction of an allylic proton by an oxygen of the TiO2.
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Language |
Greek |
Subject |
allylic alcohols |
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concerted mechanism |
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epoxides |
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gold nanoparticles |
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heterogeneous catalysis |
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terpenes |
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zeolite |
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αλλυλικές αλκοόλες |
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εποξείδια |
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ετερογενής κατάλυση |
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ζεόλιθος |
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νανοσωματίδια χρυσού |
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σύγχρονος μηχανισμός |
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τερπένια |
Issue date |
2009-12-16 |
Collection
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School/Department--School of Sciences and Engineering--Department of Materials Science and Technology--Doctoral theses
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Type of Work--Doctoral theses
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Permanent Link |
https://elocus.lib.uoc.gr//dlib/6/e/c/metadata-dlib-d714a3c291c77eebb838b1c428961f35_1264489121.tkl
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Views |
443 |