Tuning the reactivity and chemoselectivity of electron-poor pyrroles as dienophiles in cycloadditions with electron-rich dienes
作者:Antony Chrétien、Isabelle Chataigner、Serge R. Piettre
DOI:10.1016/j.tet.2005.06.016
日期:2005.8
Activation by Lewis acid catalysis and high pressure allows pyrrole derivatives to react with electron-rich dienes in normal electron demand [4+2] cycloadditions, provided that the aromatic ring is substituted by at least two electron-withdrawing groups. The dienophilic behavior of the heterocycle is expressed through the involvement of either the aromatic carbon–carbon double bond in an all-carbon
路易斯酸催化和高压激活可以使吡咯衍生物与富电子的二烯在正常的电子需求[4 + 2]环加成反应,前提是芳香环被至少两个吸电子基团取代。杂环的双亲行为是通过全碳过程中的芳族碳-碳双键或杂环加成反应中取代基的羰基部分参与来表达的。在这方面,表明杂环取代基的性质具有显着影响,并指导环加成的反应性和化学选择性。