Palladium catalyzed addition of carbon pronucleophiles to conjugated enynes
作者:Vladimir Gevorgyan、Chie Kadowaki、Matthew M. Salter、Isao Kadota、Shinichi Saito、Yoshinori Yamamoto
DOI:10.1016/s0040-4020(97)00602-9
日期:1997.7
Palladium catalyzed addition of certain carbon pronucleophiles 2 to conjugatedenynes 1 afforded the corresponding allenes 3 in good to excellent yields. The most reactive methynes such as methylmalononitrile 2c enabled to undergo double addition leading to alkenes 4. Catalyst optimization supported Pd2(dba)3• CHCl3 -dppf combination as the best system among all catalysts tested. The plausible mechanisms
Synthesis of Vinylcycloheptadienes by the Nickel-Catalyzed Three-Component [3 + 2 + 2] Cocyclization. Application to the Synthesis of Polycyclic Compounds
The nickel-catalyzed [3 + 2 + 2] cycloaddition of ethylcyclopropylideneacetate and conjugated enynes proceeded smoothly and divinylcycloheptadienes were isolated in high yields. The three-componentcocyclization of ethylcyclopropylideneacetate, conjugated enynes, and (trimethylsilyl)acetylene also proceeded in a highly selective manner to afford vinylcycloheptadienes, which were reacted with various