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Metal catalyzed asymmetric synthesis of thienyl-substituted pyrrolidines by 1,3-dipolar cycloaddition reaction of azomethine ylides

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2019
Bulut, Merve
Pyrrolidines are structurally and biologically important heterocyclic compounds. One of the efficient methods for the synthesis of these compounds is 1,3-dipolar cycloaddition (1,3-DC) reaction of azomethine ylides with electron deficient dipolarophiles. Asymmetric synthesis of these compounds has been studied by many groups by using 1,3-DC reactions with chiral transition metal catalysts. In all these studies aryl-substituted pyrrolidines were synthesized mainly. In this thesis, heteroaryl-substituted pyrrolidines which were not explored in the literature will be synthesized by using chiral metal catalysts developed in our group. Chiral metal catalysts are composed of a metal and a chiral ligand. As the metal source, Cu-, Zn-, and Ag-salts were used with FAM (ferrocenyl aziridinyl methanol) chiral ligands. Besides the known FAM ligands, a new derivative, CFAM (cyclohexyl ferrocenyl aziridinyl methanol), was also synthesized for the first time in this thesis. With the CFAM chiral ligands, total of twelve chiral ligands (PFAM1-4, CFAM1-4, and 1-NFAM1-4) were screened for the synthesis of thienyl-substituted pyrrolidines. After optimizing all the reaction parameters (temperature, concentration, solvent, etc.), Ag-PFAM1 catalyst system found to be the better one by forming thienyl-substituted pyrrolidines in 85% ee and 64% yield with N-methylmaleimide.