Synthesis of Trifluoromethylated Isoxazolidines: 1,3-Dipolar Cycloaddition of Nitrosoarenes, (Trifluoromethyl)diazomethane, and Alkenes

Isoxazolidines have proven to be important substrates in synthetic organic chemistry. Limited examples in the literature that provide trifluoromethylated versions of these compounds have prompted us to investigate a 1,3-dipolar cycloaddition route providing access to N-functionalized isoxazolidines containing a trifluoromethyl group. Thus, a 1,3-dipolar cycloaddition of nitrosoarenes, (trifluoromethyl)diazomethane, and alkenes was developed. The starting materials can be synthesized from easy to handle and accessible reagents. The reaction proved to be tolerant of a variety of electron-deficient alkenes and nitrosoarenes.