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Identifier

000361764

Title

Κυκλοϊσομερισμοί ενυνίων καταλυόμενοι απο νανοσωματίδια Au/TiO2

Alternative Title

Cycloisomerization of enynes catalyzed by nanoparticles Au/TiO2

Author

Εφέ, Χριστίνα Α

Thesis advisor

Στρατάκης, Μανόλης

Abstract

In the current Thesis we studied for the first time the cycloisomerization of aryl propargyl ethers and [1,6]-enynes under heterogeneous conditions catalyzed by Au nanoparticles supported on titania (Au/TiO₂). The results can be summarized as follows: • Au nanoparticles supported on TiO₂ (Au/TiO₂) were used as a heterogeneous gold-based catalyst for the cycloisomerization of aryl propargyl ethers. Au/TiO₂ catalyze selectively the formation of 2Η-chromenes. The 2Η-chromenes are formed via a 6-endo-dig cyclization catalyzed by either Au(Ι) or Au(ΙΙΙ) ionic species on the titania surface. • During the Au nanoparticles-catalyzed cycloisomerization of aryl propargyl ethers, dimeric products were isolated resulting from a catalytic oxidative dimerization process. This pathway is catalyzed by Au(ΙΙΙ) and the role of oxidant is undertaken provided by the atmosperic oxygen. • Au/TiO₂ is an excellent catalyst in the cycloisomerization of [1,6]-enynes. The product distribution differs significantly from the corresponding Au(I)-catalyzed reaction under homogeneous conditions.

Language

Greek

Subject

2H-chromenes

2H-χρωμένια

Aryl propargyl ethers

Gold nanoparticles

Heterogeneous catalysis

Oxidative dimerization

[1,6]-enynes

[1,6]-ενύνια

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