Nickel-Catalyzed [4+2+2]-Type Annulation Reaction of Cyclobutanones with Diynes and Enynes
In the presence of a nickel(0) catalyst, cyclobutanones reacted with diynes to produce bicyclic eight-membered ring ketones. Cyclobutanones acted as a C4 unit in the formal [4+2+2]-type annulation reaction, which proceeded through a ring-expansion of a spirocyclic seven-membered oxanickelacycle to a nine-membered nickelacycle via β-carbon elimination. A similar annulation reaction was also examined with enynes.
- Bulletin of the Chemical Society of Japan
Bulletin of the Chemical Society of Japan 81(7), 885-893, 2008-07-15
The Chemical Society of Japan