Preparation and atropisomerism of 1-(2-aryl)-piperidin-2-ones

Course and rate of the dehydrogenation of N-tertiary piperidines dependent on their substitution in 4-position and on the hydroxy bearing neighbor gro up were examined, using mercury(II)-EDTA and the model amino alcohols 1a-1e , 3a-3f, 8a-8f and 10a-10f. The results showed that increasing size of LC-s ubstituents and neighbor groups too decreased the rate of reaction. The pro ducts from the 2-substituted benzylic alcohols, the 2-piperidones 7a-7g, 9a -9g and 11a-11g demonstrated atropisomerism. In the case of chiral neighbor groups diastereomeric mixtures were formed.