Fam-zinc catalyzed asymmetric 1,3-dipolar cycloaddition reactions of azomethine ylides and

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2007

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Koyuncu, Hasan

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In the first part of this study, four new chiral ligands (FAM) were synthesized and used in catalytic amounts in asymmetric 1,3-dipolar cycloaddition reactions of azomethine ylides. This method leads to the synthesis of chiral pyrrolidines, which are found in the structure of many biologically active natural compounds and drugs. It was found that using 10 mol% of one of these chiral ligands with different dipolarophiles (dimethyl maleate, dimethyl fumarate, methyl acrylate, tert-butyl acrylate, and Nmethylmaleimide), pyrrolidine derivatives could be synthesized in up to 94% yield and 95% ee. In the second part of the study, the catalytic activity of these chiral ligands were tested with titanium in asymmetric alkynylzinc addition reactions to aldehydes. By this method, chiral propargylic alcohols, which are important precursors for the natural products and pharmaceuticals can be synthesized. Using our catalyst, chiral propargylic alcohols were obtained in up to 96% yield and 98% ee. Although, most of the catalyst systems in the literature worked only with aromatic or aliphatic aldehydes and phenylacetylene, the catalyst system developed in this study worked with four different types of aldehydes (aromatic, aliphatic, heteroaromatic and a,b-unsaturated) and two different aliphatic acetylenes very successfully. Additionally, chiral ligand can be recovered in more than 90% yield and reused without losing its activity.

Subject Keywords

Chemistry, Organic

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http://etd.lib.metu.edu.tr/upload/2/12608783/index.pdf
https://hdl.handle.net/11511/17280

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Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

H. Koyuncu, “Fam-zinc catalyzed asymmetric 1,3-dipolar cycloaddition reactions of azomethine ylides and,” Ph.D. - Doctoral Program, Middle East Technical University, 2007.