Unexpected C−C Bond Cleavage and C−C Bond Formation Observed in the Reaction of a Cationic Iridium Complex with Heteroatom-Substituted Cyclopropanes

Iridium complex Cp*(PMe 3 )Ir(CH 3 )OTf ( 1 ) and alkylaminocyclopropanes react via a well-understood initial C−H bond activation with a subsequent C−C bond-breaking step to yield a variety of π-allyl complexes [Cp*(PMe 3 )Ir(η 3 -C 3 H 4 NR 1 R 2 )][OTf] (R 1 = R 2 = Bn; R 1 = Bn, R 2 = Ph) and methane. However, diphenylamino, alkoxy, or siloxycyclopropanes, when treated with complex 1, yield a new π-allyl complex [Cp*(PMe 3 )Ir(η 3 -C 3 H 4 CH 3 )][OTf] ( 8 ) and the corresponding amine or alcohol. The methyl group initially bound to iridium is no longer extruded as methane, but instead is incorporated into the allyl moiety to give a new carbon−carbon bond. A detailed mechanistic study provides evidence in support of an initial C−C bond activation mechanism as opposed to the initial C−H bond activation observed with other known substrates.