ja7b01833_si_001.pdf (3.85 MB)
Rh2(II)-Catalyzed Ring Expansion of Cyclobutanol-Substituted Aryl Azides To Access Medium-Sized N‑Heterocycles
journal contribution
posted on 2017-03-29, 20:04 authored by Wrickban Mazumdar, Navendu Jana, Bryant T. Thurman, Donald J. Wink, Tom G. DriverA new reactivity pattern of Rh2(II)-N-arylnitrenes was discovered that facilitates
the synthesis of medium-sized N-heterocycles from ortho-cyclobutanol-substituted
aryl azides. The key ring-expansion step of the catalytic cycle is
both chemoselective and stereospecific. Our mechanistic
experiments implicate the formation of a rhodium N-arylnitrene catalytic intermediate and reveal that sp3 C–H bond amination of this electrophilic species is competitive
with the ring-expansion process.