Asymmetric diethylzinc addition to N-sulphonyl and N-phosphinoyl arylaldimines

Download

index.pdf

Date

2013

Author

Çağlı, Eda

Metadata

Show full item record

Item Usage Stats

186
views

82
downloads

Design of new chiral ligands for asymmetric synthesis is important. The ligand should be economical and efficient in enantioselective transformations. For the synthesis of some natural products and biologically active compounds, optically active amines are used as important intermediates. For this reason, it is significant to develop new catalyst system which can produce optically active amines in an economical and efficient way. Our group developed PFAM ligands and used successfully for the enantioselective synthesis of organic compounds. In this work, these ligands were tested as chiral catalysts for enantioselective synthesis of amines. N-sulphonyl and N-phosphinoyl imines synthesized from aromatic aldehydes were used as the starting material for enantioselective diethylzinc addition reaction in the presence of copper salt and PFAM ligands. By improving the known procedure, N-benzylidine sulphonylaldimine was obtained in excellent yield (98%). Asymmetric diethylzinc addition reaction to N-sulphonyl and N-phosphinoyl aryaldimines provided chiral amines in up to 81% enantioselectivity and 99% yield.

Subject Keywords

Asymmetric synthesis., Chirality., Arylation., Asymmetry (Chemistry)., Organic compounds

URI

http://etd.lib.metu.edu.tr/upload/12615394/index.pdf
https://hdl.handle.net/11511/22430

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Asymmetric synthesis of norbornene based 1,4-Aminoalcohol derivatives and applications in asymmetric diethylzinc reactions Erdem, Mine; Tanyeli, Cihangir; Department of Chemistry (2007) The asymmetric synthesis of chiral norbornene based 1,4-aminoalcohols and their applications in asymmetric diethylzinc addition reactions was perfomed starting from meso-anhydride 50. The desymmetrization of this meso-anhydride 50 was done by the usage of quinine or quinidine cinchona alkaloids with very high enantiomeric excess values (up to 98% ee) and chemical yields. The Quinidine-mediated desymmetrization of meso-anhydride 50 with methanol gave (2R,3S)-(+)-cis-monoester 51. The amination of this result...
Asymmetric aldol addition of alpha-azido ketones to ethyl pyruvate mediated by a cinchona-based bifunctional urea catalyst Okumus, Seda; Tanyeli, Cihangir; Demir, Ayhan Sıtkı (Elsevier BV, 2014-07-30) The first asymmetric synthesis of ethyl 4-aryl-3-azido-2-hydroxy-2-methyl-4-oxobutanoates via a cinchona organocatalyst induced aldol addition of alpha-azido ketones to ethyl pyruvate has been developed. The coupling reaction under optimized conditions was carried out to furnish tetrafunctionalized synthons with enantioselectivities of up to 91:9 and enriched diastereoselectivities of up to 95:5 (syn:anti).
Bifunctional 2-aminodmap/thiourea catalyzed enantioselective michael addition of thioacetic acid to trans-beta-nitrostyrenes Kabasakal, Zehra; Tanyeli, Cihangir; Department of Chemistry (2013) Michael addition reactions as an efficient method for carbon-carbon bond formations have been intensively explored in the context of enantioselective organocatalysis using aldehydes, ketones, 1,3- dicarbonyl compounds and nitroalkenes as donors. However, there are very few studies using thiol derivative as a nucleophile. In this thesis, enantioselective Michael addition reaction of thioacetic acid as Michael donor and 10 trans-β-nitrostyrene derivatives as Michael acceptors have been studied. The products o...
Asymmetric synthesis of N-aryl substituted chiral 1,4-aminoalcohol derivatives and applications in various asymmetric transformation reactions Odabaş, Serhat; Tanyeli, Cihangir; Department of Chemistry (2007) The asymmetric synthesis of N-aryl substituted chiral 1,4-aminoalcohols and their applications in asymmetric borane reduction and enantioselective diethylzinc addition to benzaldehyde reactions were performed starting from meso-anhydride 51 that is the cycloadduct of cyclopentadiene and maleic anhydride. The desymmetrization of meso-anhydride 51 was achieved by using quinine or quinidine with very high enantiomeric excess value (up to 98% ee) and with high chemical yield. The quinine-mediated desymmetrizati...
Asymmetric synthesis of norbornene based 1,4-amino alcohol derivatives and applications in asymmetric transformations Sünbül, Murat; Tanyeli, Cihangir; Department of Chemistry (2005) The asymmetric synthesis of cis-1,4-aminoalcohols with norbornene backbone was performed starting with simple and cheap anhydride 30. Quinine-mediated desymmetrization of anhydride 30 with methanol resulted in (2S,3R)-(-)-cis-hemiester 31 (98% e.e.). Chemoselective amination with HMPTA and NH4OH followed by LAH reduction afforded (2S,3R)-(+)-36 and (2S,3R)-(-)-37, respectively. The amidoester (2S,3R)-(-)-32 was transformed into chiral ligand (2S,3R)-(-)-35 with Grignard reaction followed by LAH reduction. T...

Citation Formats

E. Çağlı, “Asymmetric diethylzinc addition to N-sulphonyl and N-phosphinoyl arylaldimines,” M.S. - Master of Science, Middle East Technical University, 2013.