Your browser does not support JavaScript!

Home    Μετασχηματισμός πολυενικών τερπενίων και εποξειδίων ετερογενώς καταλυόμενοι από το ζεόλιθο Μ-Υ και από νανοσωματίδια Au/TiO2  

Results - Details

Add to Basket
[Add to Basket]
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 Ράπτης, Χρήστος Νικολάου
Thesis advisor Στρατάκης, Μανώλης
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.
Language Greek
Subject allylic alcohols
concerted mechanism
epoxides
gold nanoparticles
heterogeneous catalysis
terpenes
zeolite
αλλυλικές αλκοόλες
εποξείδια
ετερογενής κατάλυση
ζεόλιθος
νανοσωματίδια χρυσού
σύγχρονος μηχανισμός
τερπένια
Issue date 2009-12-16
Collection   School/Department--School of Sciences and Engineering--Department of Materials Science and Technology--Doctoral theses
  Type of Work--Doctoral theses
Views 328

Digital Documents
No preview available

Download document
View document
Views : 16