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In order to develop a resolution procedure for a given racemic compound, the first and the most important step is finding the most suitable resolving agent. We studied 18 individual resolutions that were carried out with resolving agents having high eutectic composition. We found that very high enantiomeric excess values were obtained in all cases. We assume that the eutectic composition of a given resolving agent is one of the most important properties that should always be considered during the search for the most efficient resolving agent., (© 2016 Wiley Periodicals, Inc.)

Efficient synthesis of several new atropisomeric amino alcohols having 1-phenyl-1H-pyrrole skeleton are reported. Steric arrangements of the products were confirmed by a single-crystal X-ray measurement. The consequences of the size of the N-substituents on enantioinduction were examined by employing the enantioselective catalytic addition of diethylzinc to a series of substituted benzaldehydes (yields 91-97%, up to 85% enantiomeric excess). The special effect of the ortho methoxy group of the substrate on the enantioinduction is also interpreted., (© 2014 Wiley Periodicals, Inc.)

An efficient synthetic method has been developed for the preparation of a new family of atropisomeric amino alcohols with 1-phenylpyrrole backbone. The synthesis is based on the different reactivities of the two carboxylic groups in optically active 1-[2-carboxy-6-(trifluoromethyl)phenyl]-1H-pyrrole-2-carboxylic acid (1). The chemical structures of the key intermediates were confirmed by spectroscopic methods and single crystal X-ray diffraction measurements. The very first application of a new optically active amino alcohol as catalyst for the enantioselective addition of diethylzinc to benzaldehyde demonstrated the practical usefulness of atropisomeric compounds in which there are six-atom chains between the two functional groups., (© 2012 Wiley Periodicals, Inc.)

Efficient enzyme catalyzed kinetic resolutions of a synthetically useful chiral building block, (Z)-4-triphenylmethoxy-2,3-epoxybutan-1-ol, are reported. The highest selectivities were achieved by Lipozyme TL IM and Amano Lipase PS enzymes in the presence of vinyl acetate. Enantiomeric enrichment of the optically active acetate isomer was accomplished by selective crystallization of the racemic part of the enantiomeric mixture. Enzyme catalyzed hydrolysis of the acetate also provided an optically pure epoxybutanol derivative. O-Benzylation of (+)-(Z)-1-hydroxy-4-triphenylmethoxy-2,3-epoxybutane followed by super base promoted diastereo- and enantio-selective rearrangement resulted in (+)-(2R,3R,1'R)-3-[1-hydroxy-2-(triphenylmethoxy)ethyl]-2-phenyloxetane in >98% ee and de. Configurations of the new optically active products were determined by chemical correlation.