83976-41-4Relevant articles and documents
Enantioselective telomerization 1. Telomerization of butadiene with formaldehyde, β-dicarbonyl compounds, nitroalkanes, and enamines
Keim, Wilhelm,Koehnes, Angela,Roethel, Thomas,Enders, Dieter
, p. 295 - 301 (1990)
Enantioselective telomerization reactions catalyzed by homogeneous palladium catalysts are described.Applying the concept of chiral bidentate phosphorus ligands and low temperatures proved useful in telomerizing butadiene with formaldehyde, with a β-dicarbonyl compound and with a nitroalkane.Excess of enantiomers up to 41percent could be obtained.With a chiral enamine as nucleophile ee values of 72percent have been observed.
Stereocontrolled Syntheses of Mannich Bases and γ-Amino Alcohols
Risch, Nikolaus,Esser, Achim
, p. 233 - 238 (2007/10/02)
The reaction of enantiomerically pure SMP enamines 2 with iminium tetrachloroaluminates 3 yields optically active Mannich bases 4.Diastereoselective reduction of 4 gives γ-amino alcohols 5 with the desired configuration. Key Words: Mannich bases / Enamines / Iminium salts / γ-Amino alcohols
Asymmetrische Michael-Additionen. Praktisch vollstaendig diastereo- und enantioselective Alkylierungen des Enamins aus Cyclohexanon und Prolinylmethylaether durch ω-Nitrostyrole zu u-2-(1'-Aryl-2'-nitroaethyl)cyclohexanonen
Blarer, Stefan J.,Schweizer, W. Bernd,Seebach, Dieter
, p. 1637 - 1654 (2007/10/02)
When the enamine (S)-N-(1'-cyclohexenyl)-2-methoxymethyl-pyrrolidine is added to 2-aryl-1-nitroethylenes, only one of the four possible enantiomerically pure diastereomers is formed.Hydrolysis of the crude primary products furnishes α-alkylated cyclohexanones of >90percent e.e. (3, Scheme 3).Their (2S,1'R)-configuration was deduced by chemical correlation with 1-cyclohexyl-1-phenyl-ethane and from an X-ray crystal structure analysis of (-)-(2R,3S,6'R,1''S)-3-methyl-N--2-phenylmorpholine (11a, Scheme 5 and Fig. 2). - The relative topicity of reactant approach with the prolinol derivative (see II) is specified as 1k,ul-1,4.The steric course and the mechanism of the reaction are discussed.