Aza Diels–Alder Reactions of Nitriles, <i>N</i>,<i>N</i>-Dimethylhydrazones, and Oximino Ethers. Application in Formal [2 + 2 + 2] Cycloadditions for the Synthesis of Pyridines
作者:Philip J. Hamzik、Anne-Sophie Goutierre、Takeo Sakai、Rick L. Danheiser
DOI:10.1021/acs.joc.7b02503
日期:2017.12.15
Metal-free, formal [2 + 2 + 2] cycloaddition strategies for the synthesis of polycyclic pyridine derivatives are described. The overall transformation proceeds via a two-stage pericyclic cascade mechanism. In the first step, an intramolecular propargylic enereaction generates a vinylallene that is necessarily locked in the s-cis conformation. This vinylallene exhibits exceptional reactivity as a Diels–Alder
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.