Synthesis of cyclopentadienones
A one-pot reaction of carbon dioxide with 1,4-dilithio-1,3-diene derivatives affords cyclopentadienone derivatives bearing various substituents in high yields within minutes.
Z. Xi, Q. Song, J. Org. Chem., 2000, 65, 9157-9159.
The Rh(I)-catalyzed [3 + 2] cycloaddition of cyclopropenones and alkynes provides a highly efficient and regioselective route to cyclopentadienones (CPDs) that would be otherwise difficult to obtain. The versatility of the method is explored with a wide range of alkynes and diaryl- as well as arylalkylcyclopropenones.
P. A. Wender, T. J. Paxton, T. J. Williams, J. Am. Chem. Soc., 2006, 128, 14814-14815.