Unexpected C-C Bond Cleavage and C-C Bond Formation Observed in the Reaction of a Cationic Iridium Complex with Heteroatom-Substituted Cyclopropanes
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- 作者：Mitchell R. Anstey ; Cathleen M. Yung ; Juana Du ; Robert G. Bergman
- 刊名：Journal of the American Chemical Society
- 出版年：2007
- 出版时间：January 31, 2007
- 年：2007
- 卷：129
- 期：4
- 页码：776 - 777
- 全文大小：46K
- 年卷期：v.129,no.4(January 31, 2007)
- ISSN：1520-5126
文摘
Iridium complex Cp*(PMe3)Ir(CH3)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 
-allyl complexes [Cp*(PMe3)Ir(
3-C3H4NR1R2)][OTf] (R1 = R2 = Bn; R1 = Bn, R2 = Ph) and methane. However, diphenylamino, alkoxy, or siloxycyclopropanes, when treated with complex 1, yield a new -allyl complex [Cp*(PMe3)Ir(3-C3H4CH3)][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.
-allyl complexes [Cp*(PMe3)Ir(3-C3H4NR1R2)][OTf] (R1 = R2 = Bn; R1 = Bn, R2 = Ph) and methane. However, diphenylamino, alkoxy, or siloxycyclopropanes, when treated with complex 1, yield a new -allyl complex [Cp*(PMe3)Ir(3-C3H4CH3)][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.