Modularly Evolved 2-AminoDMAP/Squaramides as Highly Active Bifunctional Organocatalysts in Michael Addition

Date

2015-01-16

Author

Isik, Murat
Unver, M. Yagiz
Tanyeli, Cihangir

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We report a new family of chiral bifunctional acid/base type organocatalysts, 2-aminoDMAP/Squaramides, which are proved to be highly active (1 mol % cat. loading) promoters in conjugate addition of dibenzoylmethane to various trans-beta-nitroalkenes. Steric demand of the catalysts was clearly seen by a set-by-set modulation of the squaramide unit through electronic and steric factors. The synergistic cooperation of 2-aminoDMAP "superbase" and sterically encumbered squaramide (H-bond donor) enabled complete conversion of a range of reactants into corresponding Michael adducts in a couple of hours with exquisite selectivities (up to 98% ee).

Subject Keywords

Chiral proton catalysis, Flexible guanidine/bisthiourea organocatalyst, Alpha-keto esters, 1,3-dicarbonyl compounds, Asymmetric catalysis, Enantioselective synthesis, Bronsted acid, Contiguous stereocenters, Squaramide derivatives, Cascade reaction

URI

https://hdl.handle.net/11511/47766

Journal

JOURNAL OF ORGANIC CHEMISTRY

DOI

https://doi.org/10.1021/jo5022597

Collections

Department of Chemistry, Article

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Citation Formats

M. Isik, M. Y. Unver, and C. Tanyeli, “Modularly Evolved 2-AminoDMAP/Squaramides as Highly Active Bifunctional Organocatalysts in Michael Addition,” JOURNAL OF ORGANIC CHEMISTRY, pp. 828–835, 2015, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47766.