140925-20-8Relevant articles and documents
On the mechanism of the organocatalytic asymmetric epoxidation of α,β-unsaturated aldehydes
Davis, Rebecca L.,Jensen, Kim L.,Gschwend, Bjoern,Jorgensen, Karl Anker
, p. 64 - 67 (2014)
Mechanistic studies on the organocatalytic epoxidation of α,β-unsaturated aldehydes explore the autoinductive behavior of the reaction and establish that the hydrate/peroxyhydrate of the product is acting as a phase-transfer catalyst. Based on these studies, an improved methodology that provides high selectivities and decreased catalyst loading, through the addition of chloral hydrate, is developed. Self-promotion: Mechanistic studies on the organocatalytic epoxidation of α,β-unsaturated aldehydes reveal the autoinductive behavior and establish that the hydrate/peroxyhydrate of the product is acting as a phase-transfer catalyst. Based on these results, an improved methodology that provides high selectivities and decreased catalyst loading, through the addition of chloral hydrate, has been developed (see scheme). Copyright
An organocatalytic approach to 2-hydroxyalkyl- and 2-aminoalkyl furanes
Albrecht, Lukasz,Ransborg, Lars Krogager,Gschwend, Bjoern,Jorgensen, Karl Anker
supporting information; experimental part, p. 17886 - 17893 (2011/02/23)
The first enantioselective methodology for the synthesis of electron-poor 2-hydroxyalkyl- and 2-aminoalkyl furanes is demonstrated in this study. It utilizes a highly stereoselective organocatalytic one-pot reaction cascade: epoxidation or aziridination o
Amine-catalyzed asymmetric epoxidation of α,β-unsaturated aldehydes
Zhao, Gui-Ling,Ibrahem, Ismail,Sunden, Henrik,Cordova, Armando
, p. 1210 - 1224 (2008/09/17)
The direct organocatalytic enantioselective epoxidation of α,β-unsaturated aldehydes with different peroxides is presented. Proline, chiral pyrrolidine derivatives, and amino acid-derived imidazolidinones catalyze the asymmetric epoxidation of α,β-unsatur
Direct organocatalytic asymmetric epoxidation of α,β-unsaturated aldehydes
Sundén, Henrik,Ibrahem, Ismail,Córdova, Armando
, p. 99 - 103 (2007/10/03)
The organocatalytic asymmetric epoxidation of α,β-unsaturated aldehydes with peroxides or sodium percarbonate is presented. Chiral pyrrolidine derivatives, proline and amino acid derived imidazolidinones mediate the asymmetric epoxidation of α,β-unsaturat
Asymmetric organocatalytic epoxidation of α,β-unsaturated aldehydes with hydrogen peroxide
Marigo, Mauro,Franzen, Johan,Poulsen, Thomas B.,Zhuang, Wei,Jorgensen, Karl Anker
, p. 6964 - 6965 (2007/10/03)
The first asymmetric organocatalytic epoxidation of α,β-unsaturated aldehydes is presented. A chiral bisaryl-silyl-protected pyrrolidine acts as a very selective epoxidation organocatalyst using simple oxidation agents, such as hydrogen peroxide and tert-butyl hydroperoxide. The asymmetric epoxidation reactions proceed under environmental friendly reaction condition in, for example, water mixtures of alcohols, and the scope of the reaction is demonstrated by the formation of optically active α,β-epoxy aldehydes in high yields and enantioselectivities >94% ee. Furthermore, the direct synthesis of the sex pheromone from an acaric mite by asymmetric epoxidation of citral is presented. Copyright
Enantioselective synthesis of loracarbef from sodium erythorbate
Frazier, Jeffery W.,Staszak, Mike A.,Weigel, Leland O.
, p. 857 - 860 (2007/10/02)
Sodium erythorbate (7) has been converted to loracarbef (1). Oxidation of sodium erythorbate to D erythronolactone (8) followed by selective monotosylation and treatment with sodium ethoxide provided ethyl (2S,3R) 4 hydroxy 2.3 epoxybutyrate (10). Swern oxidation of this epoxide into the aldehyde (11), imine formation with tert-butylglycinate and an enantioselective Staudinger reaction with phthalimidoacetyl chloride afforded the (3S,4S)-cis-β-lactam (13). Appropriate functional group manipulations followed by a Dieckmann condensation, chlorination, and protecting group removals gave the enantiomerically pure nucleus of loracarbef (24).
