Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Palladium Catalyzed Cross Coupling Reactions of Alkenyl Epoxides and Organoboronic Acid Esters(Izmir Institute of Technology, 2018) Eren, Ahmet; Artok, LeventIn organic chemistry, it is a useful method to form a new allylic compounds as a result of 1-3 substitution reactions of allylic compounds which have a good leaving group. These reactions usually require a metal catalyst but one of the most challenging aspects of these applications is the process regio and stereo selectivity for a wide variety of substrate types. Other compounds such as alkenyl epoxides are also useful for 1-3 substitution reactions. An advantage of using alkenyl oxirane compounds is that the oxirane ring is opened in the substitution step to form a hydroxyl group and resulted in the formation of allylic alcohols which are important intermediate product. Metal catalysed and regioselective reactions of terminal alkenyl epoxides with organoborons have been reported in the literature. However, there is no successful method for internal alkenyl oxiranes. Thus, in this study, 1-3 substitution reactions of alkenyl oxiranes were successfully applied, which yielded allylic alcohols with high regio- and stereoselectivity.Master Thesis Palladium-Catalyzed Stereo-Selective 1.2-Addition Reactions of ?,?-Epoxy Esters With Organoborons(Izmir Institute of Technology, 2018) Bilgi, Yasemin; Artok, LeventTransition metal-catalyzed SN2-type addition reactions of allylic compounds having good leaving groups is a valuable reaction procedure in organic chemistry. Vinyl epoxides, as a derivative of allylic compounds, are suitable reagents for substitution reactions with their high reactivity due to the presence of an epoxide ring tensions and a conjugated C-C double bond attached to this ring. The occurrence of a substitution reaction of such reagents over the allylic position allows synthesis of homoallylated alcohols, one of the key building blocks in the synthesis of natural compounds. Organoborans are stable against moisture and air and environmentally friendly compounds and are thought by us to be suitable nucleophiles in these reactions. Within the context of this research, Pd-catalyzed stereo-selective SN2-addition type arylation reactions of γ,δ-epoxy-α,β-unsaturated esters with organoborons were investigated. The reaction mechanism proceeds through formation of π-allylpalladium complex with the help of Pd-AsPh3 combination. The method has enabled to formation of γ-Aryl-δ-hydroxy-α,β-unsaturated esters with high regio- and stereo- selectivity.