Enantioselective Michael Addition of 4-Hydroxycoumarins to β,γ-Unsaturated α-Oxophosphonates Catalysed by a Bifunctional Squaramide Bearing a Structurally Rigid 9,10-Ethylene-9,10-dihydroanthracene Skeleton

Autor:	Hai-Bin Song, Zhenghong Zhou, Chuchi Tang, Xufang Chang, Youming Wang, Qiaohui Wang
Rok vydání:	2013
Předmět:	chemistry.chemical_compound chemistry Nucleophile Organocatalysis Organic Chemistry Enantioselective synthesis Michael reaction Squaramide Organic chemistry Amine gas treating Physical and Theoretical Chemistry 9 10-Dihydroanthracene Bifunctional
Zdroj:	European Journal of Organic Chemistry. 2013:2164-2171
ISSN:	1434-193X
DOI:	10.1002/ejoc.201201573
Popis:	A bifunctional squaramide based on (R,R)-11,12-diamino-9,10-ethylene-9,10-dihydroanthracene has been developed, and it has demonstrated great advantages over previously reported organocatalysts in the asymmetric Michael addition of 4-hydroxycoumarins to β,γ-unsaturated α-oxophosphonates. Upon quenching the generated β-4-hydroxy-2-oxo-2H-chromen-3-yl-substituted acylphosphonate intermediates with DBU and an alcohol or amine as a second nucleophile, the corresponding β-substituted carboxylates or amides were obtained in acceptable to excellent yields and with high levels of enantioselectivity (80–97 % ee) in a one-pot fashion.
Databáze:	OpenAIRE
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