Theoretical DFT study of 1,3,2-dioxa-phosphoranes formation by oxidative addition of methanol on monocyclic phospholanes

Oxidative addition of aliphatic alcohols on monocyclic phospholanes leads to the formation of monocyclic phosphoranes, exhibiting a P-H bond, which are in equilibrium with the starting materials. Theoretical DFT study has allowed us to precise the geometrical characteristics, thermodynamic and kinetic parameters, vibrational normal mode wave numbers and atomic charge distribution of intervening molecules and the transition state. According to Hammond postulate, this transition state is described as react-like type one. The analysis of the pathway obtained by the IRC method indicates that phosphoranes formation follows a two-step mechanism in which a pseudo-phosphonium ion intervenes as a reaction intermediate.