Enantioselective Michael reaction of β-keto esters organocatalyzed by recoverable Cinchona-derived dimeric ammonium salts |
| |
Authors: | Silvia Tarí Rafael Chinchilla Carmen Nájera |
| |
Institution: | Departamento de Química Orgánica, Facultad de Ciencias, and Instituto de Síntesis Orgánica (ISO), Universidad de Alicante, Apdo 99, 03080 Alicante, Spain |
| |
Abstract: | Dimeric anthracenyldimethyl-derived Cinchona ammonium salts are used as chiral organocatalysts in 1–10 mol % for the enantioselective conjugate addition of 2-alkoxycarbonyl-1-indanones to β-unsubstituted Michael acceptors. The corresponding adducts bearing a new all-carbon quaternary center were usually obtained in high yield and with up to 94% ee when using ammonium salts derived from quinidine and its pseudoenantiomer quinine as organocatalysts. These catalysts can be almost recovered quantitatively by precipitation in ether and reused. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |