الفهرس 
General Part
Synthesis of some selenium-containing five-membered ring systemsOnly 14 pages are availabe for public view
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Abstract
The aim of the present work is to design and synthesize novel analogues to the well-known organo-seleno drug, ebselen [2-phenyl-1,2-benzisoselenazol-3(2H)-one, (1)] and assessment of their glutathione peroxidase (GPx) like activity. Also functionalized benzoselenophenes are targeted as they are valuable bioactive compounds and interesting building blocks for construction of fused heterocyclic systems. Another main goal for this work is to synthesize novel chiral diselenides and hypervalent iodine reagents as they are highly desirable synthetic targets where such compounds are valuable reagents and catalysts for stereoselective chemical transformations such as stereoselective functionalization of olefins and stereoselective carbo- and heterocyclization reactions. The obtained results can be summarized as follow: 1. Nine novel chiral Ebselen analogues were synthesized and characterized using physical and spectroscopic techniques. 2. The GPx-like activity of ebselen 1 and the chiral ebselen analogues 9–17 was determined using two different methods one in the presence of thiophenol (PhSH) and the other in the presence of glutathione (GSH) using glutathione disulfide reductase, each with two different peroxides, hydrogen peroxide (H2O2) and cumene hydroperoxide (CumOOH) as the substrates. The results of GPx-like activity shows that most of the tested chiral ebselen analogues have quite similar activities to ebselen 1, only 16 stands out in showing a higher activity in the assays performed. 3. Some novel benzo[b]selenophene derivatives were synthesized and characterized using physical and spectroscopic techniques. 4. Novel chiral alcohol 45 and its O-methylated derivative 44 were obtained stereoselectively with more than 99.9% ee through the stereoselective reduction of the prochiral ketone 46 using a Ruthenium catalyst. 5. The absolute configuration of the alcohol 45 found to be (R) and it was determined via deiodination of 45 to 57 and comparing the optical rotation of 57 with literature. 6. Our trials to convert 44 to the novel chiral diselenide 41 were unsuccessful. On the other hand, it was easily converted into the novel hypervalent iodine reagent 56. 7. Two novel chiral amides 67 and 69 were synthesized in excellent yield and converted successfully to the corresponding chiral diselenides 43a and 43b.