Tarí Segarra, Silvia, Chinchilla, Rafael, Nájera, Carmen, Yus, Miguel
Enantioselective alkylation of β-keto esters promoted by dimeric Cinchona-derived ammonium salts as recoverable organocatalysts
ARKIVOC. 2011, 2011(7): 116-127
URI: http://hdl.handle.net/10045/34356
DOI: 
ISSN: 1551-7004 (Print)
Abstract: 
Dimeric anthracenyldimethyl-derived Cinchona ammonium salts are used as chiral organocatalysts in 5 mol% for the phase-transfer enantioselective alkylation reaction of 2-alkoxycarbonyl-1-indanones with activated bromides. The corresponding adducts bearing a new all-carbon quaternary center are obtained usually in high yield and with moderate and opposite enantioselectivity (up to 55%) when using ammonium salts derived from quinidine and its pseudoenantiomer quinine as organocatalysts. These catalysts can be almost quantitatively recovered by precipitation in ether and reused.
Keywords:Asymmetric synthesis, Ammonium salts, Phase-transfer catalysis, Alkylation, β-keto esters
Arkat USA, Inc.
info:eu-repo/semantics/article