Highly Efficient Recyclable Co III –salen Complexes in the Catalyzed Asymmetric Aminolytic Kinetic Resolution of Aryloxy/Terminal Epoxides for the Simultaneous Production of N ‐Protected 1,2‐Amino Alcohols and the Corresponding Epoxides in High Optical Purity

Chiral Co III –salen complexes 1 – 6 bearing different substituents at the 3,3′‐ and 5,5′‐positions of the salen unit, namely H, t Bu, morpholinomethyl, and piperidinomethyl, have been synthesized. These complexes were used as catalysts in an environmentally benign protocol for the highly enantiosel...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:European journal of organic chemistry 2009-06, Vol.2009 (17), p.2863-2871
Hauptverfasser: Kureshy, Rukhsana I., Prathap, K. Jeya, Agrawal, Santosh, Kumar, Manish, Khan, Noor‐ul H., Abdi, Sayed H. R., Bajaj, Hari C.
Format: Artikel
Sprache:eng
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Chiral Co III –salen complexes 1 – 6 bearing different substituents at the 3,3′‐ and 5,5′‐positions of the salen unit, namely H, t Bu, morpholinomethyl, and piperidinomethyl, have been synthesized. These complexes were used as catalysts in an environmentally benign protocol for the highly enantioselective aminolytic kinetic resolution (AKR) of racemic aryloxy/terminal epoxides with various carbamates as the nucleophile in the presence of different ionic liquids at room temperature. Excellent yields (>99 % with respect to the nucleophile) of N ‐protected 1,2‐amino alcohols with high regio‐ and enantioselectivities ( ee >99 %) were achieved with the simultaneous formation of the corresponding epoxides with high chiral purity ( ee up to >99 %) and in quantitative yields with catalyst 1 in the ionic liquid [bmim]PF 6 as the reaction medium in around 5 h. The catalyst is recyclable in this ionic‐liquid‐mediated AKR process (up to six cycles with no loss of performance), and the process is five times faster than the homogeneous process performed with conventional organic solvents.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
ISSN:1434-193X
1099-0690
DOI:10.1002/ejoc.200900032