Grubbs Katalizörlerinin Amin Fonksiyonlu Polistiren Desteğe İmmobilizasyonu ve Olefin Metatez Tepkimelerindeki Aktivitelerinin ve Etkinliklerinin Karşılaştırmalı Olarak İncelenmesi
Özet
The targeted reaction's activation energy can be lowered by metal catalysts, which play a role in controlling the mechanism of product formation. The recovery of these catalysts through isolation from the product mixture with high conversion efficiency, allowing for their reusability, is of significant importance in terms of sustainability, adherence to the principles of green chemistry, and cost considerations. Notably, the presence of residual metal catalysts in the reaction mixture after the completion of the reaction may increase the steps of purification of the product and pose a risk of reducing product yield indirectly. Additionally, this can pose problems in using the product/product mixture containing metal catalysts in subsequent reaction steps or storing the product/product mixture.
The presented thesis study aims to investigate the in-situ immobilization of commercially available Grubbs first-generation (Grubbs-1) and Grubbs second-generation (Grubbs-2) catalysts, belonging to the ruthenium-based catalyst class which is increasingly popular in recent years due to their high activity and functional group tolerance in olefin metathesis reactions and tungsten aryloxide catalyst complexes as a reference catalyst in targeted metathesis reactions on amine-functionalized polystyrene-based crosslinked microsphere-shaped polymer support synthesized in laboratory conditions. The activity of the target catalysts, in the self-metathesis reactions of non-cyclic olefin samples (1-octene and trans-2-octene) and in the ring-opening metathesis polymerization (ROMP) reaction of norbornene with ring-strain, will be thoroughly evaluated under different reaction parameters and the removal of the catalyst systems from the reaction environment will also be examined.
In this regard, the substrate type, reaction time, reaction temperature, olefin/catalyst ratio, and amine-functionalized poly(styren-co-divinylbenzen) (PS-DVB) support for Grubbs-1 and Grubbs-2 metathesis catalysts have been thoroughly investigated in order to determine the optimum reaction conditions for the targeted metathesis reactions. The final products and reaction yield obtained by metathesis of 1-octene or trans-2-octene as the starting material was determined by GC-MS analysis. Additionally, the analysis of the polymeric products obtained by the ring-opening reaction of norbornene was carried out by FT-IR, 1H NMR, and 13C NMR methods. Our research group has previously conducted metathesis reactions of 1-octene, trans-2-octene, and norbornene compounds in the presence of a tungsten aryloxide catalyst complex. The experimental data obtained from these reactions will be used in the present thesis to evaluate the activity and product selectivity parameters of Grubbs-1 and Grubbs-2 catalysts, by comparing the results obtained from metathesis reactions using the same starting materials with the same catalysts.
