Brønsted Acid TfOH-Mediated [3 + 2] Cycloaddition Reactions of Diarylvinylidenecyclopropanes with Nitriles
摘要:
Diarylvinylidenecyclopropanes undergo a [3 + 2] cycloaddition reaction with MeCN in the presence of Bronsted acid TfOH to give the corresponding 3,4-dihydro-2H-pyn-ole derivatives 2 in moderate to excellent yields under reflux within a short time. As for the diarylvinylidenecyclopropane substrate containing a strongly electron-donating methoxy group on the benzene ring, the reaction leads to the formation of a different type of 3,4-dihydro-2H-pyrrole derivatives 4 under the same conditions.
Lewis Acid Catalyzed Cascade Reactions of Diarylvinylidenecyclopropanes and 1,1,3-Triarylprop-2-yn-1-ols or Their Methyl Ethers
作者:Min Shi、Liang-Feng Yao
DOI:10.1002/chem.200800421
日期:2008.9.26
The reactions of vinylidenecyclopropanes 1 with 1,1,3-triarylprop-2-yn-1-ols or their methyl ethers 2 in the presence of a Lewisacid selectively produce 4-dihydro-1H-cyclopenta[b]naphthalene derivatives 3 or 1,2,3,8-tetrahydrocyclopenta[a]indene derivatives 4 depending on the substituents on the cyclopropane. Good to high yields are obtained under mild conditions. A plausible cascade Meyer-Schuster