Cyano Diels−Alder and Cyano Ene Reactions. Applications in a Formal [2 + 2 + 2] Cycloaddition Strategy for the Synthesis of Pyridines
作者:Takeo Sakai、Rick L. Danheiser
DOI:10.1021/ja106901u
日期:2010.9.29
Two metal-free, formal [2 + 2 + 2] cycloaddition strategies for the construction of polycyclic pyridine derivatives are described that proceed via pericyclic cascade mechanisms featuring the participation of unactivated cyano groups as enophile and dienophile cycloaddition partners.
[structure: see text] Callyberynes A and B, polyacetylenic hydrocarbons from Callyspongia sp., have been synthesized for the first time using highly convergent approaches based on optimized Cadiot-Chodkiewicz (Alami, Vasella) and sequential Sonogashira cross-coupling reactions.