Optically Active Amines by Enzyme-Catalyzed Kinetic Resolution
作者:Klaus Ditrich
DOI:10.1055/s-2008-1078451
日期:2008.7
Chiral amines are resolved by an enzyme-catalyzed kineticresolution. Key steps are the selective acylation of one enantiomer with isopropyl methoxyacetate, separation of the resulting amide from the unreacted antipode, and finally amide hydrolysis. The process proceeds with excellent selectivity and is highly flexible with regard to substrates.
non-enzymatic kinetic resolution of primaryamines via enantioselective N-acylation with acyl chlorides was accomplished for the first time by using the selective sequestration of one enantiomer within a supramolecular cyclodextrin (CD) nanocapsule in nonpolar solvents. In addition, the first example of a crystalline structure for an inclusion complex between an acyl chloride and a CD derivative is reported
tetrahydrofuran. High chiralrecognition of aromatic amines and alcohol is realized by utilizing inclusion within the cavity of the TBDMS-β-CD dimer in cyclohexane. In particular, an extremely high binding selectivity for (S)-1-(1-naphthyl)ethylamine and (S)-1-(1-naphthyl)ethanol over the corresponding (R)-isomers is achieved. Moreover, by utilizing the high chiralrecognition with the TBDMS-β-CD dimer
Merging Nucleophilic and Hydrogen Bonding Catalysis: An Anion Binding Approach to the Kinetic Resolution of Amines
作者:Chandra Kanta De、Eric G. Klauber、Daniel Seidel
DOI:10.1021/ja9079435
日期:2009.12.2
A new concept for asymmetric nucleophilic catalysis is presented. Acyl pyridinium salts derived from 4-(dimethylamino)pyridine (DMAP) and benzoic anhydride are rendered chiral via interaction with a chiral thiourea anion receptor. The power of this concept is demonstrated in the context of kinetic amine resolution.
Chiral Recognition and Kinetic Resolution of Aromatic Amines via Supramolecular Chiral Nanocapsules in Nonpolar Solvents
Herein we report the first example of chiral recognition and kinetic resolution of aromatic amine guests using supramolecular nanocapsules assembled from cyclodextrin derivatives in nonpolar media. With these nanocapsules, an extremely high chiral recognition of 1-(1-naphthyl)ethylamine (1) in cyclohexane was achieved, with a binding selectivity of up to 41 for (S)-1 over (R)-1. In addition, kinetic resolution of 1 through enantioselective N-acylation was accomplished with an enantiomeric excess of up to 91%.