Synthesis of Bridged Cycloisoxazoline Scaffolds via Rhodium-Catalyzed Coupling of Nitrones with Cyclic Carbonate

Bridged isoxazolidines were synthesized via Rh-(III)-catalyzed C-H allylation of alpha-aryl nitrones with 5-methylene-1,3-dioxan-2-one. The nitrone group serves as a directing group and 1,3-dipole in the C-H activation/[3 + 2] cycloaddition cascade, exhibiting excellent chemo- and stereoselectivity along with good functional group compatibility. The resulting skeletal structure was conveniently modified to produce a range of important chemical frameworks, and the protocol was applied to biologically active molecules.

Automated summary

Bridged isoxazolidines were synthesized via Rh-(III)-catalyzed C-H allylation of alpha-aryl nitrones with 5-methylene-1,3-dioxan-2-one. The nitrone group acted as a directing group and 1,3-dipole in the C-H activation/[3 + 2] cycloaddition cascade, showing excellent chemo- and stereoselectivity as well as good functional group compatibility. The resulting compounds' skeletal structure could be conveniently modified and applied in the synthesis of biologically active molecules.