posted on 2020-11-11, 13:37authored byXiao-Wei Zhang, Xiao-Lin He, Nan Yan, Hong-Xing Zheng, Xiang-Guo Hu
A facile
oxidative heterocyclization of commercially available
amines and tert-butyl nitrite with alkynes or alkenes
leading to isoxazoles or isoxazolines is described. The unprecedented
strategy of the oxidation of an amine directly to a nitrile oxide
was used in this cyclization process. This reaction is highly efficient,
regiospecific, operationally simple, mild, and tolerant of a variety
of functional groups. Control experiments support a nitrile oxide
intermediate mechanism for this novel class of oxidative cyclization
reactions. Moreover, synthetic applications toward bioactive molecular
skeletons and the late-stage modification of drugs were realized.