Described herein is the RhI-catalyzed ortho-alkylation of aromatic ketimines or ketones with olefins. This method showed high reactivity and selectivity to monoalkylation for a variety of olefins including 1-alkenes with an allylic proton, a,w-dienes, and internal olefins. For a mechanistic study, H/D exchange experiments were carried out, which demonstrated that the ortho C-H bond could be easily cleaved even at the low temperature of 45°C. The key step of this reaction is the formation of a stable five-membered metallacycle by a chelation-assisted ortho C-H bond activation. Furthermore, the direct ortho-alkylation of aromatic ketones with the RhI complex was successfully achieved by adding 50 mol % of benzylamine as a chelation-assistant tool.
|Number of pages||8|
|Journal||Chemistry - A European Journal|
|Publication status||Published - 2002 Jan 18|
All Science Journal Classification (ASJC) codes
- Organic Chemistry