The rearrangement of N-propargyl-morpholine-N-oxide yielding an O-propadienyl-hydroxylamine derivative (Meisenheimer-type Route A) and a formyl-enamin type product in protic solvent (Route B) were investigated by theoretical methods. As the determination of both the exact energy profile and the structures of the transition states and intermediates is rather uncertain for reactions in a protic solvent catalyzed by proton-transfer, a new method was elaborated by applying one or two MeOH molecules associated with the reactant. On this basis the one-step mechanism for the concurrent reactions suggested by experimental results was controlled and corrected in some respect. The competitive rearrangements may proceed through a common intermediate formed in the rate-determining step, which play an important role only in protic environment stabilized by hydrogen bonds.
- Competitive rearrangements
- DFT method
- Meisenheimer sigmatropic rearrangement
- Modelling in protic solvent
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry