117306-12-4Relevant articles and documents
Study on the (R)-oxynitrilase activity of Pouteria sapota
Solís, Aida,Luna, Héctor,Manjarrez, Norberto,Pérez, Herminia I.
, p. 10427 - 10431 (2004)
Mamey (Pouteria sapota) defatted meal was used to catalyze the enantioselective addition of HCN to α,β-unsaturated aldehydes. Using a biphasic system of diisopropyl ether and citrate buffer (0.1 M, pH 5.0, 10% v/v), the (R)-cyanohydrins obtained showed go
Regio- and Stereospecific C- and O-Allylation of Phenols via φ-Allyl Pd Complexes Derived from Allylic Ester Carbonates
Discolo, Christopher A.,Graves, Alexander G.,Deardorff, Donald R.
, p. 1034 - 1045 (2017)
Two complementary strategies have been developed for the C- and O-allylation of phenols via a common φ-allyl Pd complex. While O-allylation of phenols by this method is a well-recognized reaction of general utility, the associated para-selective C-allylation reaction is still in its infancy. Cationic φ-allyl Pd intermediates, derived from allylic ester carbonates and palladium(0) catalyst, were found to undergo the Friedel-Crafts-type para-selective C-allylations with nine different phenols. Both C- and O-allylated products were obtained in good to excellent yields following a metal-catalyzed regio- and stereospecific substitutive 1,3-transposition. Conditions were also identified that control access to either allylated product. Finally, a study of the equilibrium established between the two allylation products revealed that the O-allylated compound was the kinetic product and the C-allylated compound the thermodynamic product.
'Gelozymes' in organic synthesis. (Part 3): Lipase mediated synthesis of enantiomerically pure (R)- and (S)-enantiomers of 2-acetoxy-4-phenyl-(E)-but-3- enenitrile
Fadnavis, Nitin W.,Radhika, Kasiraman R.,Madhuri, Kallakunta Vasantha
, p. 549 - 553 (2004)
Lipases such as Candida rugosa lipase and Pseudomonas cepacia (Amano Ps) lipase immobilized in gelatin gels (gelozymes) exhibit very high enantioselectivities (E>200) during alcoholysis of racemic 2-acetoxy-4-phenyl-(E)-but-3-enenitrile with n-butanol in hexane and diisopropyl ether. C. rugosa lipase in n-hexane shows selectivity towards the (R)-ester while P. cepacia (Amano Ps) lipase shows selectivity towards the (S)-ester producing the corresponding cyanohydrins. After decomposition of the cyanohydrin by treatment with 1M imidazole solution to cinnamaldehyde and its removal by bisulfite treatment, (R)- or (S)-enantiomer of 2-acetoxy-4-phenyl-(E) -but-3-enenitrile can be obtained in high yields (90%) and high enantiomeric excess (>99%).
α-Pinene-type chiral Schiff bases as tridentate ligands in asymmetric addition reactions
Jaworska, Magdalena,Blocka, Ewelina,Kozakiewicz, Anna,Welniak, Miroslaw
experimental part, p. 648 - 657 (2011/07/08)
A group of tridentate Schiff bases derived from (+)-α-pinene were synthesized. The steric effects in the transition state, the importance of π-π stacking interactions as well as the electronic effects of aryl aldehydes according to Hammett constant values in the enantioselective addition of Et2Zn to aldehydes with the use of Schiff bases as chiral ligands are described. Also, a variety of aldehydes were cyanated using a catalyst prepared in situ from titanium tetraisopropoxide and chiral Schiff bases. The influence of a conjugated double-bond in the cyanation substrates on enantioselectivity was observed. The chemical structures of the chiral Schiff base-titanium alkoxide complexes are discussed based on their 1H and 13C NMR spectra. 3D models of the Zn2-complex catalyst and Ti-complex catalyst containing α-pinane-type Schiff bases based on X-ray diffraction experiments are postulated. The models presented were consistent with the reported chirality of the addition product and observed ee.
[Ru(phgly)2(binap)]/Li2CO3: A Highly Active, Robust, and Enantioselective Catalyst for the Cyanosilylation of Aldehydes
Kurono, Nobuhito,Arai, Kenta,Uemura, Masato,Ohkuma, Takeshi
supporting information; experimental part, p. 6643 - 6646 (2009/03/12)
The right combination: A series of aromatic, heteroaromatic, aliphatic, and α,β-unsaturated aldehydes can be converted into the desired silylated cyanohydrins by reaction with (CH3)3SiCN and a catalyst system consisting of the combination of a chiral ruthenium complex and Li2CO3 (see scheme). The reaction is highly enantioselective and affords the R products with up to 98% ee within 24 h at a substrate-tocatalyst ratio of 10000:1. (Chemical Equation Presented).
