Construction of Chiral Quaternary Carbon through Morita-Baylis-Hillman Reaction: An Enantioselective Approach to 3-Substituted 3-Hydroxyoxindole Derivatives
作者:Xiao-Yang Guan、Yin Wei、Min Shi
DOI:10.1002/chem.201002240
日期:2010.12.10
A new enantioselectiveapproach to obtain a tetrasubstituted chiral center at the C3 position of oxindoles via a catalytic asymmetric Morita–Baylis–Hillmanreaction has been demonstrated. This reaction provides 3‐substituted 3‐hydroxy‐2‐oxindoles in good to excellent yields and ee values, which could be facilely transformed to pharmaceutically more interesting compounds.
Aza-Morita–Baylis–Hillman reactions catalyzed by a cyclopropenylidene
作者:Xun Lu、Uwe Schneider
DOI:10.1039/c6cc06201f
日期:——
Catalysis using a bis(dialkylamino)cyclopropenylidene (BAC) has been developed, which relies on a formal umpolung activation of Michael acceptor pro-nucleophiles.
Catalytic, Asymmetric Aza-Baylis-Hillman Reaction ofN-Sulfonated Imines with Activated Olefins by Quinidine-Derived Chiral Amines
作者:Min Shi、Yong-Mei Xu、Yong-Ling Shi
DOI:10.1002/chem.200400872
日期:2005.3.4
such as methyl vinyl ketone (MVK), ethyl vinyl ketone (EVK), acrolein, methylacrylate, phenyl acrylate, or alpha-naphthyl acrylate to give the corresponding adducts in moderate to good yields with good to high ee (up to 99 %) at -30 degrees C or 45 degrees C in various solvents, including DMF/MeCN (1:1, v/v). The first such reaction of 1 with the simplest Michael acceptor MVK and methylacrylate has been
Recoverable Cinchona ammonium salts as organocatalysts in the enantioselective Michael addition of β-keto esters
作者:Silvia Tarí、Rafael Chinchilla、Carmen Nájera
DOI:10.1016/j.tetasy.2010.11.016
日期:2010.12
Several dimeric Cinchona-alkaloid anthracenyldimethyl-derived ammoniumsalts, are used as organocatalysts in the enantioselective Michael addition reaction of cyclic β-ketoesters to α,β-unsaturated carbonyl compounds, in the presence of diisopropylethylamine as a base (30 mol %), for the generation of enantiomerically enriched adducts bearing quaternary stereocenters. Quinine and quinidine-derived
acid-catalyzed asymmetricBaylis-Hillmanreaction is described. Good to high enantioselectivities were obtained using 3 mol % chiral catalyst. Novel camphor-derived dimerized ligands were prepared from the condensation of (+)-ketopinic acid with the corresponding diamines and hydrazine under acidic conditions. When alpha-naphthyl acrylate was used as a Michael acceptor, the reaction is complete within