Organocatalyzed Asymmetric Vinylogous Addition of Oxazole-2(3H)-thiones to α,ß-Unsaturated Ketones: An Additive-Free Approach for Diversification of Heterocyclic Scaffold.
J Org Chem
; 83(4): 1701-1716, 2018 02 16.
Article
em En
| MEDLINE
| ID: mdl-29337556
ABSTRACT
A straightforward organocatalyzed asymmetric addition of oxazole-2(3H)-thiones to α,ß-unsaturated ketones is described. This additive-free Michael reaction in the presence of chiral cinchonine-derived primary amines as catalysts has proven to be highly effective for a wide range of cyclic and acyclic enones, leading to the Michael adducts in very good yields and excellent enantioselectivities. The absolute configuration (R) of compound 5j was unambiguously assigned by X-ray diffraction analysis. Furthermore, experimental and theoretical studies were performed and a mechanism is presented and discussed for this novel reaction.
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MEDLINE
Idioma:
En
Revista:
J Org Chem
Ano de publicação:
2018
Tipo de documento:
Article