Bifunctional squaramide catalyzed stereoselective Mannich reaction of α-azido ketones with isatin-derived ketimines

Asymmetric organocatalytic Mannich reaction of α-azido ketones and N -Boc protected isatin-derived ketimines were investigated for the first time. Examination of both 2-adamantyl and 3,5-bis(trifluoromethyl)aniline substituted quinine-based squaramides afforded chiral Mannich bases with two contiguo...

Full description

Saved in:
Bibliographic Details
Published inOrganic & biomolecular chemistry Vol. 18; no. 3; pp. 479 - 487
Main Authors Karahan, Seda, Tanyeli, Cihangir
Format Journal Article
LanguageEnglish
Published England Royal Society of Chemistry 22.01.2020
Subjects
Adducts
Aniline
Crystallography
High-performance liquid chromatography
Imines
Ketones
Liquid chromatography
NMR
Nuclear magnetic resonance
Quinine
Stereoselectivity
Online AccessGet full text

Cover

More Information
Summary:Asymmetric organocatalytic Mannich reaction of α-azido ketones and N -Boc protected isatin-derived ketimines were investigated for the first time. Examination of both 2-adamantyl and 3,5-bis(trifluoromethyl)aniline substituted quinine-based squaramides afforded chiral Mannich bases with two contiguous stereogenic centers in high yields (up to 97%) and stereoselectivity (up to dr = 24 : 1 syn  :  anti and 96% ee). Azido and masked amino functionalities of the potent heterocycle precursor adducts were utilized in representative examples. Bifunctional squaramide catalyzed asymmetric Mannich reaction of alpha-azido ketones and isatin derived ketiminines were established for the first time with high stereoselectivity. Adducts are valuable synthons for optically active heterocycles.
Bibliography:For ESI and crystallographic data in CIF or other electronic format see DOI
10.1039/c9ob02208b
NMR spectra and HPLC chromatograms. CCDC
Electronic supplementary information (ESI) available: X-ray structure of compound
3g
1919849
ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:1477-0520
1477-0539
DOI:10.1039/c9ob02208b