Facile Generation and Isolation of π‑Allyl Complexes from Aliphatic Alkenes and an Electron-Deficient Rh(III) Complex: Key Intermediates of Allylic C–H Functionalization

It has been established that a strongly
electrophilic η5-cyclopentadienylrhodium complex,
[CpERhCl2]2, is capable of reacting
with aliphatic alkenes in the presence of a silver salt and cesium
acetate at room temperature to give the corresponding π-allyl
complexes in high yields. The use of an alkenyltosylamide as the alkene
also afforded the corresponding π-allyl complex. Treatment of
the thus obtained π-allyl complex with a silver­(I) salt and
copper­(II) acetate afforded the allylic amination product, which proves
the intermediacy of this π-allyl complex in the rhodium­(III)-catalyzed
intramolecular oxidative allylic amination.