A catalyticenantioselectiveStreckerreaction catalyzed by novel chiral lanthanum(III)−binaphthyl disulfonate complexes was developed. The key to promoting the reactions was a semistoichiometric amount of AcOH or i-PrCO2H, which takes advantage of HCN generation in situ. The corresponding cyanation products were obtained in high yields and with high enantioselectivities.
Asymmetric Strecker Reaction ofN-Benzhydrylimines Utilising New Tropos Biphenyldiol-Based Ligands
作者:Stefan Wünnemann、Roland Fröhlich、Dieter Hoppe
DOI:10.1002/ejoc.200700763
日期:2008.2
intermediates together with easily accessible N-arenesulfonylamino alcohols furnish a broad variety of 1,3-oxazolidines. These are applied as chiral tropos ligands in a titanium-mediated Strecker-type reaction of N-benzhydrylimines. A correlation between the ee values in the product and the diastereomeric ratio concerning the chiral axis of the ligand is made. Those substituents in the ligand which proved
Enantioselective Synthesis of α-Amino Nitriles from <i>N</i>-Benzhydryl Imines and HCN with a Chiral Bicyclic Guanidine as Catalyst
作者:E. J. Corey、Michael J. Grogan
DOI:10.1021/ol990623l
日期:1999.7.1
[formula: see text] A novel catalytic enantioselective Strecker synthesis of chiral alpha-amino nitriles and alpha-amino acids is described and analyzed with regard to the possible mechanistic basis for stereoselectivity. Key features of the enantioselective process include (1) the use of the chiral bicyclicguanidine 1 as catalyst and (2) the use of the N-benzhydryl substituent on the imine substrate
<i>C</i><sub>2</sub>-Symmetric Recyclable Organocatalyst for Enantioselective Strecker Reaction for the Synthesis of α-Amino Acid and Chiral Diamine- an Intermediate for APN Inhibitor
作者:S. Saravanan、Arghya Sadhukhan、Noor-ul H. Khan、Rukhsana I. Kureshy、Sayed H. R. Abdi、Hari C. Bajaj
DOI:10.1021/jo300349f
日期:2012.5.4
Recyclable chiral amide-based organocatalyst 5 efficiently catalyzed asymmetric Streckerreaction of various aromatic and aliphatic N-benzhydrylimines with ethyl cyanoformate as cyanide source at −10 °C to give a high yield (95%) of α-aminonitriles with excellent chiral induction (ee, up to 99%) with the added advantage of recyclability. Based on experimental observations a probable mechanism was proposed
A practical procedure for catalytic asymmetric synthesis of opticallyactive arylglycine derivatives viaopticallyactive α-aminonitriles has been developed. The N-benzhydryl α-arylaminonitrile intermediates were prepared in excellent yield (89–99%) and enantiomeric purity (96 to >98% ee) by enantioselective cyanation of aldimines with TMSCN/iPrOH in the presence of 2.5 mol % of an easily prepared