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Coupling constants provide important information on the conformation of molecules in solution. At present, four of the ten possible coupling constants n J HH have been experimentally determined for tetrahydrofuran (THF) and tetrahydrothiophene (THT) [1]. We have used these data to evaluate the parameters of the dynamic structure of the THF and TTF molecules in a new scheme for conformational analysis involving the quantum-chemical description of the dynamic systems in terms of large-amplitude oscillations. X = O, S Fig. 1. Conformational space of THF and THT. __________________________________________________________________________________________ 1

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The stereochemistry of 2′-methylbutyrophenone oxime, the rates of ortho-palladation of its E-and Zisomers, and catalytic activity of the respective Pd complexes were studied. The full stereoisomeric composition of oximes was established for the first time by means of supercritical fluid chromatography on chiral polysaccharide column. It was shown that enantiomeric excesses of both E/Z-isomers of (S)-2′-methylbutyrophenone oxime (1S) and (R)-2′-methylbutyrophenone oxime (1R) were equal to 92 ± 2. The cyclopalladation study revealed that while E-isomer is orthopalladated very quickly its Z-counterpart does not enter this reaction. However, upon coordination to Pd(II), Z-oxime slowly isomerizes into E-form with fast subsequent cyclopalladation, so it was possible to perform ortho-palladation of E-oxime in kinetic resolution mode with removal of unreacted Zoxime. Comparatively rare cis-structure of cyclopalladated oxime dimer was proved by means of single-crystal X-ray study. For the first time, it was shown that ortho-palladated chiral oximes behave as enantioselective catalyst in the hydrolysis of chiral esters.

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