Intramolecular Arylation of Tertiary Enamides through Pd(OAc)2‑Catalyzed Dehydrogenative Cross-Coupling Reaction: Construction of Fused N‑Heterocyclic Scaffolds and Synthesis of Isoindolobenzazepine Alkaloids

Pd­(OAc)2-catalyzed intramolecular dehydrogenative cross-coupling reaction between tertiary enamides, which were derived from the condensation of 2-arylethylamines and methyl o-acetylbenzoate, and arenes enabled synthesis of 7,8-dihydro-5H-benzo­[4,5]­azepino­[2,1-a]­isoindol-5-one derivatives under mild conditions. The synthetic method was applied in the total synthesis of aporhoeadane alkaloids palmanine, lennoxamine, and chilenamine in only three or four steps.以乙酸钯(II) (Pd(OAc)2)为催化剂，由2-芳基乙胺与邻乙酰苯甲酸甲酯经缩合反应得到的三级烯酰胺，与芳烃之间发生的分子内脱氢交叉偶联反应，可在温和条件下合成7,8-二氢-5H-苯并[4,5]氮杂卓并[2,1-a]异吲哚-5-酮类衍生物。该合成方法仅需3至4步，即可应用于阿朴啡烷生物碱棕榈明碱（palmanine）、莱诺胺（lennoxamine）及奇伦胺（chilenamine）的全合成。