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。