1201-85-0Relevant academic research and scientific papers
Diastereoselective hydrogenation of α,β-unsaturated but-2-enamides to access the chiral 3-(p-tolyl) butanoic acids
Jiménez, Jacqueline,López, Mildred,Carranza, Vladimir,Mendoza, Angel,Varela, Jenaro,Sansinenea, Estibaliz,Ortiz, Aurelio
, p. 235 - 239 (2016/12/28)
An alternative methodology for the synthesis of chiral 3-(p-tolyl) butanoic acids is presented. This was accomplished through the diastereoselective hydrogenation reaction of different chiral N-3-(p-tolyl) but-2-enamides, using Pd/C in EtOH, to produce the corresponding chiral N-3-(p-tolyl) butanamides with high chemical yields and moderate diastereomeric ratios. Removal of the chiral auxiliary from N-3-(p-tolyl) butanamides gave the respective enantiomerically pure acids.
Highly efficient Rh-catalyzed asymmetric hydrogenation of α,β-unsaturated nitriles
Yan, Qiaozhi,Kong, Duanyang,Li, Meina,Hou, Guohua,Zi, Guofu
, p. 10177 - 10181 (2015/09/01)
A highly efficient enantioselective hydrogenation of α,β-unsaturated nitriles catalyzed by Rh-(R,R)-f-spiroPhos complex has been developed. With Rh-(R,R)-f-spiroPhos catalyst and under mild conditions, a wide range of α,β-unsaturated nitriles including the (E)- and (Z)-isomers of 3-alkyl-3-aryl, 3,3-diaryl, and 3,3-dialkyl α,β-unsaturated nitriles were hydrogenated to the corresponding chiral nitriles with excellent enantioselectivities (up to 99.9% ee) and high turnover numbers (TON up to 10,000).
Lipase catalysed kinetic resolutions of 3-aryl alkanoic acids
Deasy, Rebecca E.,Brossat, Maude,Moody, Thomas S.,Maguire, Anita R.
, p. 47 - 61 (2011/04/18)
Hydrolase catalysed kinetic resolutions leading to a series of 3-aryl alkanoic acids (≥94% ee) are described. Hydrolysis of the ethyl esters with a series of hydrolases was undertaken to identify biocatalysts that yield the corresponding acids with excellent enantiopurity in each case. Steric and electronic effects on the efficiency and enantioselectivity of the biocatalytic transformation were also explored.
Total synthesis of (R)- and (S)-turmerone and (7S,9R)-bisacumol by an efficient chemoenzymatic approach
Kamal, Ahmed,Shaheer Malik,Azeeza, Shaik,Bajee, Shaik,Shaik, Ahmad Ali
experimental part, p. 1267 - 1271 (2009/10/17)
An enantioselective synthesis of (R)-, (S)-turmerone and (7S,9R)-bisacumol is described. The enantiomerically pure key intermediates, a substituted butanoate ester and acid are utilized in the synthesis of both enantiomers of turmerone. The lipase catalyzed resolution studies of the acetate of bisacumol have been exploited towards the total synthesis of the naturally occurring cytotoxic sesquiterpene, (7S,9R)-bisacumol with high diastereoselectivity (94% de).
Enantioselective synthesis of (R)- and (S)-curcumene and curcuphenol: an efficient chemoenzymatic route
Kamal, Ahmed,Malik, M. Shaheer,Shaik, Ahmad Ali,Azeeza, Shaik
, p. 2547 - 2553 (2008/03/15)
An efficient enantioselective synthesis of curcumene and curcuphenol is described. The key intermediates, substituted butanoates 7a and 7b and their acids 8a and 8b are obtained in high enantiopurity (>99% ee) by a lipase-catalyzed kinetic resolution proc
Determination of the Enantiomeric Excesses of Chiral Acids by 19F NMR Studies of their Esters deriving from (R)-(+)-2-(Trifluoromethyl)benzhydrol
Brown, Eric,Chevalier, Christelle,Huet, Francois,Grumelec, Christelle Le,Leze, Antoine,Touet, Joel
, p. 1191 - 1194 (2007/10/02)
15-Chiral acids were esterified with optically pure (R)-(+)-2-(trifluoromethyl)benzhydrol (R)-(+)-1, a readily available reagent.With respect to the carboxy group, the stereogenic centre is in the β-position in the case of the acids 5a-10a and 12a-16a, and in the α position in the case of the acids 17a-20a.The diastereomeric excesses of the corresponding esters 5b-10b and 12b-20b, respectively, were easily determined by means of 19F NMR.These d.e. values were in very good agreement with the e.e. values of the corresponding acids when the latter were known compounds.
Synthesis of (+)-Turmeronol A, an Inhibitor of Soybean Lipoxygenase, and (+)-ar-Turmerone
Kitahara, Takeshi,Furusho, Yoshio,Mori, Kenji
, p. 1137 - 1140 (2007/10/02)
Syntheses of optically pure turmeronol A and turmerone were achieved in a simple manner starting from ethyl (R)-3-hydroxybutanoate (4) of 100percent e.e.The key step was the displacement of the chiral tosylate (6) with an organocopper reagent.
ASYMMETRIC CONJUGATE ADDITION REACTION BY THE USE OF (S)-γ-TRITYLOXYMETHYL-γ-BUTYROLACTAM AS A CHIRAL AUXILIARY
Tomioka, Kiyoshi,Suenaga, Toshiro,Koga, Kenji
, p. 369 - 372 (2007/10/02)
(S)-γ-Trityloxymethyl-γ-butyrolactam (2) serves as a chiral auxiliary in the conjugate addition reaction of the corresponding imide (3) of α,β-unsaturated carboxylic acids with Grignard reagents in the presence of CuBr-SMe2 in THF to give, after hydrolysis, the β,β-disubstituted carboxylic acids (5) with predictable absolute configuration and high enantiomeric excess.
