Jacobsen-type enantioselective hydrolysis of aryl glycidyl ethers.<sup>31</sup>P NMR analysis of the enantiomeric composition of oxiranes
作者:A. A. Bredikhin、E. I. Strunskaya、V. G. Novikova、N. M. Azancheev、D. R. Sharafutdinova、Z. A. Bredikhina
DOI:10.1023/b:rucb.0000024851.29744.21
日期:2004.1
The enantioselective partial hydrolysis of a number of racemic arylglycidylethers in the presence of chiral Co(salen)-catalyst was studied. The enantiomeric composition of the isolated (R)-aryl glycidylethers was analyzed by 31P NMR using optically active substituted 2-chloro-1,3,2-dioxaphospholanes. A synthesis of β-adrenoblocking agents (S)-toliprolol and (S)-moprolol based on the simultaneously
Crystallization of chiral compounds 3. 3-phenoxypropane-1,2-diol and 3-(2-halophenoxy)propane-1,2-diols
作者:D. V. Zakharychev、S. N. Lazarev、Z. A. Bredikhina、A. A. Bredikhin
DOI:10.1007/s11172-006-0243-x
日期:2006.2
Specific features of melting of crystalline samples of 3-(2-R-phenoxy)propane-1,2-diols with different enantiomeric compositions were studied by differential scanning calorimetry. The melting points and enthalpies of melting for the racemate and individual stereoisomers were determined. Binary phase diagrams were constructed. The entropy of mixing of individual enantiomers in the liquid phase and the free energy of formation of the racemic compound were calculated. The thermochemical data indicate that the racemates are formed upon the crystallization of phenoxy-and 2-fluorophenoxy-containing compounds, while crystallization of the chloro-, bromo-, and iodo-substituted analogs would form racemic conglomerates.
The phenyl glycidyl ether derivatives have been kinetically resolved with the growing cells of Bacillus alcalophilus MTCC10234 yielding (S)-epoxides with up to >99% ee and (R)-diols with up to 89% ee. The enantiomeric ratio (E) of up to 67 has been obtained for biohydrolysis process. The effect of different substituents of phenyl glycidyl ether on the biocatalytic efficiency of B. alcalophilus MTCC10234
Systematic search for conglomerates among glycerol aromatic monoethers: guaifenesin and mephenesin are the cases
作者:Alexander A. Bredikhin、Zemfira A. Bredikhina、Sergey N. Lazarev、Dmitry V. Savel’ev
DOI:10.1070/mc2003v013n03abeh001752
日期:2003.1
Within the family of biologically active 3-aryloxy-1,2-propanediols, three new conglomerate-forming compounds have been found resolved into enantiomers using the entrainment procedure.