Enantioselective sulfa-Michael addition reaction of methyl thioglycolate to chalcones derivatives with sterically encumbered quinine squaramide organocatalyst

Date

2018-04-04

Author

HASILCIOĞULLARI, DENİZ
Tanyeli, Cihangir

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

193
views

0
downloads

Asymmetric organocatalytic sulfa-Michael reactions give access to enantiomerically enriched sulfur containing adducts that can be used as valuable chiral building blocks. A variety of chalcone derivatives were allowed to react with methyl thioglycolate under optimized conditions, in the presence of a bifunctional quinine derived sterically encumbered squaramide organocatalyst, giving rise to excellent stereoselectivities, up to 99% ee. The designed catalyst system proved to be efficient even at gram scale and under milder reaction conditions.

Subject Keywords

Sulfa-Michael addition, Conjugate addition, Organocatalysis, Asymmetric synthesis, Asymmetric catalysis

URI

https://hdl.handle.net/11511/38785

Journal

TETRAHEDRON LETTERS

DOI

https://doi.org/10.1016/j.tetlet.2018.02.068

Collections

Department of Chemistry, Article

Suggestions

OpenMETU
Core

Asymmetric synthesis of 2,3-dihydrofurans with bifunctional quinine / squaramide organocatalysts Bozdemir, Merve; Tanyeli, Cihangir; Department of Chemistry (2019) Organocatalytic asymmetric reactions are efficient and environmentally friendly methods to synthesize products with higher enantioselectivities. Asymmetric domino Michael-SN2 reactions are one of the type of organocatalytic reaction frequently used to form carbon-carbon bonds in the synthesis of the derivatives of dihydrofurans, which are intermediates mainly utilized as precessor materials in the pharmaceutical fields. In this thesis, the reaction occuring between acetylacetone and (Z)-(2-bromo-2-nitroviny...
Enantioselective Michael Addition of Nitroalkanes to Nitroalkenes Catalyzed by Chiral Bifunctional Quinine-Based Squaramides KANBEROĞLU, Esra; Tanyeli, Cihangir (2016-01-01) A family of chiral bifunctional acid-/base-type quinine/squaramide organocatalysts is shown to be highly active promoters of the conjugate addition of 1-nitropropane to various trans--nitroalkenes. The cooperation of the quinine and the sterically encumbered squaramide moieties catalyzed the Michael addition reactions at 0 degrees C by using a catalyst loading of only 2mol% to afford the 1,3-dinitro Michael adducts with excellent enantioselectivity and diastereoselectivity (up to 95%ee and syn/anti isomers ...
Enantioselective synthesis of 2,3-dihydrofurans using a bifunctional quinine/squaramide organocatalyst Susam, Zeynep Dilşad; Gundogdu, Gulsum; Tanyeli, Cihangir (2021-11-01) Asymmetric organocatalytic domino type Michael-S(N)2 reactions give access to enantiomerically enriched dihydrofuran derivatives that can be used as valuable chiral building blocks. A variety of alpha-bromonitroalkenes and 1,3-dicarbonyl compounds were allowed to react under optimized conditions, in the presence of a bifunctional quinine-derived sterically encumbered squaramide (H-bond donor) organocatalyst. The conditions developed in this article have great advantages over the methods known in the literat...
Enantioselective aza-Henry reaction of t-Boc protected imines and nitroalkanes with bifunctional squaramide organocatalysts Susam, Zeynep Dilşad; Tanyeli, Cihangir (2017-05-07) An organocatalytic asymmetric aza-Henry reaction of t-Boc protected imines with nitroalkanes has been established by chiral acid-base type bifunctional Cinchona alkaloid/squaramide organocatalysts. The cooperation of a quinine motif as a base and sterically encumbered squaramide (H-bond donor) enabled mostly complete conversion of a range of reactants into the corresponding aza-Henry products at room temperature with good selectivities (up to 91% ee with 10 mol% catalyst loading).
Real-time benchtop NMR spectroscopy for the online monitoring of sucrose hydrolysis Soyler, Alper; Bouillaud, Dylan; Farjon, Jonathan; Giraudeau, Patrick; Öztop, Halil Mecit (Elsevier BV, 2020-01-01) The online monitoring of chemical reactions by using benchtop Nuclear Magnetic Resonance (NMR) spectroscopy has become increasingly attractive for the past few years. The use of quantitative online NMR spectroscopy is a promising alternative to traditional analytical methods with its rapid, quantitative and non-invasive nature that makes it applicable to complex and diverse biochemical mixtures like food systems. In this study, sucrose hydrolysis by invertase was chosen as a model reaction for online monito...

Citation Formats

D. HASILCIOĞULLARI and C. Tanyeli, “Enantioselective sulfa-Michael addition reaction of methyl thioglycolate to chalcones derivatives with sterically encumbered quinine squaramide organocatalyst,” TETRAHEDRON LETTERS, pp. 1414–1416, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/38785.