129313-24-2Relevant articles and documents
Lewis acid-lewis base-catalysed enantioselective addition of α-ketonitriles to aldehydes
Lundgren, Stina,Wingstrand, Erica,Moberg, Christina
, p. 364 - 372 (2008/02/07)
Additions of structurally diverse α-ketonitriles to aromatic and aliphatic prochiral aldehydes yielding highly enantioenriched acylated cyanohydrins were achieved using a combination of a titanium salen dimer and an achiral or chiral Lewis base. In most cases high yields and high enantioselectivities were observed. The ee was moderate in the initial part of the reaction but increased over time. This could be avoided, and higher ees obtained, by keeping the titanium complex, in the presence or absence of aldehyde and ketonitrile, at -40°C prior to the addition of the Lewis base. A mechanism initiated by nucleophilic attack of the tertiary amine at the carbonyl carbon atom of the ketonitile is supported by 13C labelling experiments.
Enzymatic Preparation of Optically Active α- and β-Hydroxy Carboxylic Acid Derivatives
Kanerva, Liisa T.,Sundholm, Oskari
, p. 823 - 825 (2007/10/02)
The lipase PS-catalysed resolutions of mandelonitrile (1) and methyl and ethyl hydroxy carboxylates 2-5 have been performed using (PrCO)2O, PrCO2CH=CH2 and PrCO2CH2CF3 as achiral reagents in THF and toluene.High enantioselectivity (e.e. close to 100percent) was observed, especially when butyric anhydride was used as an acylating reagent for the secondary HO group of 2-5. The acylation using PrCO2CH2CF3 was impractical owing to the slow reaction rate.In the acylation of 1 enentioselectivity was only moderate.
