118918-39-1Relevant academic research and scientific papers
Tandem enantioselective organo- and biocatalysis: A direct entry for the synthesis of enantiomerically pure aldols
Edin, Michaela,B?ckvall, Jan-E.,Córdova, Armando
, p. 7697 - 7701 (2004)
Direct proline-catalyzed aldol reactions were linked in sequence with lipase-catalyzed kinetic resolutions to afford enantiomerically pure (>99% ee) aldol adducts in higher conversion than a standard resolution of racemic materials. The combination of organocatalytic aldol reactions and enzymatic kinetic resolutions provided exclusively either the (R)- or (S)-enantiomer of the aldol adducts even though an (R)-selective lipase catalyzed the kinetic resolutions. Furthermore, the one-pot tandem reactions are inexpensive, are operationally simple, circumvents the use of organic solvent and are environmentally benign.
Regio- and stereo-selectively kinetic resolution of four stereoisomers of 1-phenylbutan-1,3-diol by Candida rugosa lipase
Chen, Yi-Hui,Joly,Huang, Pin-Mei,Sung, Kuangsen
, p. 1031 - 1035 (2006)
Regio- and stereo-selective Candida rugosa lipase (CRL)-catalyzed acetylations of (±)-syn-1-phenylbutan-1,3-diols ((±)-syn-1) generated two monoacetates, (+)-syn-2 and (-)-syn-3, whereas that of (±)-anti-1 produced a monoacetate, (+)-anti-3, and an unreacted (-)-anti-1.
Lewis base activation of Lewis acids: Catalytic, enantioselective vinylogous aldol addition reactions
Denmark, Scott E.,Heemstra Jr., John R.
, p. 5668 - 5688 (2008/02/10)
(Chemical Equation Presented) The generality of Lewis base catalyzed, Lewis acid mediated, enantioselective vinylogous aldol addition reactions has been investigated. The combination of silicon tetrachloride and chiral phosphoramides is a competent catalyst for highly selective additions of a variety of α,β-unsaturated ketone-, 1,3-diketone-, and α,β- unsaturated amide-derived dienolates to aldehydes. These reactions provided high levels of γ-site selectivity for a variety of substitution patterns on the dienyl unit. Both ketone- and morpholine amide-derived dienol ethers afforded high enantio- and diastereoselectivity in the addition to conjugated aldehydes. Although α,β-unsaturated ketone-derived dienolate did not react with aliphatic aldehydes, α,β-unsaturated amide-derived dienolates underwent addition at reasonable rates affording high yields of vinylogous aldol product. The enantioselectivities achieved with the morpholine derived-dienolate in the addition to aliphatic aldehydes was the highest afforded to date with the silicon tetrachloride-chiral phosphoramide system. Furthermore, the ability to cleanly convert the morpholine amide to a methyl ketone was demonstrated.
Enzymatic approach to and odor description of the twelve enantiomerically pure isomers of Pelargene
Abate, Agnese,Allievi, Maurizio,Brenna, Elisabetta,Fuganti, Claudio,Gatti, Francesco G.,Serra, Stefano
, p. 177 - 189 (2007/10/03)
Pelargene is a commercial fragrance sold as a mixture of three regioisomeric pyran derivatives (1-3). The enantiomers of each of the two possible diastereoisomers of 1-3 were prepared by means of a biocatalyzed approach, and the odor properties of the twe
Lewis base activation of Lewis acids: Catalytic, enantioselective addition of silyl ketene acetals to aldehydes
Denmark, Scott E.,Beutner, Gregory L.,Wynn, Thomas,Eastgate, Martin D.
, p. 3774 - 3789 (2007/10/03)
The concept of Lewis base activation of Lewis acids has been reduced to practice for catalysis of the aldol reaction of silyl ketene acetals and silyl dienol ethers with aldehydes. The weakly acidic species, silicon tetrachloride (SiCl4), can b
Lewis base activation of Lewis acids. Vinylogous aldol reactions
Denmark, Scott E.,Beutner, Gregory L.
, p. 7800 - 7801 (2007/10/03)
A highly regioselective vinylogous aldol reaction catalyzed by SiCl4 and a chiral phosphoramide (R,R)-5, providing δ-hydroxy enones for a variety of aldehyde and dienol ether structures, has been developed. Low catalyst loadings (1 mol %) can b
