Synthesis of enantiopure (R,R)- and (S,S)-cis-2,3-propanoprolines
2010-12, Kopylova, Natalia, Grygorenko, Oleksandr O., Komarov, Igor V., Groth, Ulrich
A novel approach to the synthesis of an enantiopure bicyclic proline analogue, hexahydrocyclopenta[b]pyrrole-6a(1H)-carboxylic acid (‘2,3-propanoproline’), has been developed. The method relied on tandem Strecker-nucleophilic cyclization reaction of 2-(2-bromoethyl)cyclopentanone. The overall synthetic scheme included six steps and resulted in 18% overall yield of both enantiomers of the title amino acid.
Stereoselective Approach to New Conformationally Restricted alpha-Amino Acids,Stereoselective Synthesis of alpha-Trifluoromethylated alpha-Amino Acids
2010, Kopylova, Natalia
New optically active free amino acids, namely 2,3-ethano- and 2,3-propanoproline, were synthesized using a reaction of corresponding gamma-functionalized carbonyl compounds with 2-methyl-2-(((1S)-1-phenylethyl)amino)propanenitrile as a key step.
Approach to a new camphor-derived 2-cyanopyrrolidine and 2-cyanopiperidines was developed.
The Pd-catalyzed carboalkoxylation of 2,2,2-trifluoro-N-(p-anisyl)-acetimidoyl iodide and 2,2,2-trifluoro-N-(1-phenylethyl)-acetimidoyl iodide was investigated. The reaction conditions were optimized that gave possibility to obtain chiral imino esters.
Nucleophilic alkylation of the imino esters was performed. It was shown that the remote position of the chiral auxiliary and the nature of a nucleophile have a drastic effect on the diastereoselectivity of the reaction.