Reaction of N,N-Dimethylaniline Derivatives with Cumene Hydroperoxide. Oxazolidine Formation via Addition of α-Aminomethyl Radicals to Formaldehyde

Article abstract of DOI:10.1021/jo00157a020

The reactions of N,N-dimethylaniline derivatives (1) with cumene hydroperoxide in acetonitrile at 100 deg C produce significant amounts of the corresponding N-aryloxazolidine (6).Oxazolidine formation occurs by addition of α-aminomethyl radicals (7) to formaldehyde to give the alkoxy radical (8), followed by intramolecular 1,6 H-atom abstraction, oxidation, and cyclization.The results of labeling experiments and the dependence of the oxazolidine yield on the formaldehyde concentration support this mechanism.Alkoxy radical 8 was generated by an alternative route anddoes give the oxazolidine.Radical addition to the carbonyl carbon of formaldehyde is a reflection of the electron-rich, nucleophilic nature of the α-aminomethyl radical 7 and rapid trapping of the resulting alkoxy radical 8 via intramolecular H-atom abstraction through a six-membered transition state.