81-82-3Relevant articles and documents
First aromatic amine organocatalysed activation of α,β-unsaturated ketones
Sonsona, Isaac G.,Marqués-López, Eugenia,Gimeno, M. Concepción,Herrera, Raquel P.
, p. 12233 - 12240 (2019/08/12)
This work provides an unprecedented example of a chiral aromatic amine used to activate α,β-unsaturated ketones in asymmetric aminocatalysis. Chiral aromatic diamine VII has been efficiently employed, as a proof of concept, in the Michael addition reaction between benzylideneacetones (1a-f) and coumarins (2a-d). The reaction gives rise to warfarin derivatives 3 with promising results using this family of catalysts for the first time. The additional studies performed supported the bifunctional mode of activation of the chiral catalyst VII and the covalent nature of the interactions between the catalyst VII and benzylideneacetones 1.
Asymmetric synthesis of warfarin and its analogs catalyzed by C 2-symmetric squaramide-based primary diamines
Kochetkov, Sergei V.,Kucherenko, Alexander S.,Zlotin, Sergei G.
supporting information, p. 6423 - 6429 (2018/09/25)
Novel C2-symmetric N,N′-bis(2-amino-1,2-diphenylethyl)squaramides with 1,2-di(pyridin-2-yl)ethane and 1,2-diphenylethane spacer groups were designed and applied as organocatalysts in asymmetric additions of 4-hydroxycoumarin and 4-hydroxy-6-methyl-2H-pyran-2-one to α,β-unsaturated ketones. Both enantiomers of the anticoagulant warfarin and its analogs were prepared in up to 96% yield and with 96% ee. Recyclability of the developed catalysts and synthetic utility of the prepared Michael adducts for asymmetric synthesis of potential chiral medications via acylation reactions were demonstrated.
Asymmetric synthesis of warfarin and its analogues on water
Rogozińska-Szymczak, Maria,Mlynarski, Jacek
, p. 813 - 820 (2014/06/23)
The asymmetric Michael addition of 4-hydroxycoumarin to α,β-unsaturated ketones on water without organic co-solvents is reported to be catalysed by organic primary amines. The application of enantiomerically pure (S,S)-diphenylethylenediamine affords a series of important pharmaceutically active compounds in good to excellent yields (73-98%) and with good enantioselectivities (up to 76% ee) via reactions accelerated by ultrasound. In particular, our developments led to an efficient protocol for the 'solids on water' formation of the anticoagulant warfarin in both enantiomeric forms. The presented scalable and environmentally friendly organocatalytic approach affords the target drug in enantiomerically pure form.
