A study on the kabachnik--fields reaction of benzaldehyde, cyclohexylamine, and dialkyl phosphites

作者：Keglevich Gyoergy^*; Kiss Noera Zsuzsa; Menyhard Dora K; Fehervari Andras; Csontos Istvan

来源：Heteroatom Chemistry, 2012, 23(2): 171-178.

DOI：10.1002/hc.20767

The Kabachnik-Fields reaction of benzaldehyde, cyclohexylamine, and dimethyl phosphite carried out at 80 degrees C in acetonitrile takes place via an imine (PhC=N-degrees Hex) intermediate, as the monitoring by in situ Fourier transform IR spectroscopy suggested. The corresponding alpha-hydroxyphosphonate was also formed in a quantity of 13% that was not converted to alpha-aminophosphonate under the conditions applied. The outcome was similar to the KabachnikFields reaction with diethyl phosphite as the P-component. Molecular modeling and subsequent DFT calculations carried out under solventless conditions supported the experimental results and indicated the formation of a high number of ideally positioned H bonds as the key determinant for the conformation of the starting, intermediate, and product states. The relative energies of the possible intermediates were in accord with the observation that the formation of the alpha-hydroxyphosphonate is a dead-end route.

• 出版日期2012