Copper mediated cyclization of activated 1-substituted enamides occurs via a 5-endo radical-polar crossover process. Trichloroacetyl derivatives can undergo further reactions post cyclization (elimination of HCl or dimerization potentially via copper carbenoid intermediates). Reaction of α-halo trienamides derived from β-ionone furnish either β- or γ-lactams via 4-exo or 5-exo cyclizations respectively depending upon the enamide tautomer undergoing reaction. For the less reactive dichloroacetamide derivative a competing regioselective methyl migration-aromatization prior to cyclization is observed.

中文翻译：

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铜介导的1-取代的酰胺，二烯酰胺和三烯酰胺的环化：区域化学，靛类形成和甲基迁移-芳香化

铜介导的活化的1-取代的酰胺的环化过程是通过5-内基自由基-极性交叉过程发生的。三氯乙酰基衍生物在环化后可能会进一步反应（消除HCl或可能通过类铜铜中间体二聚化）。衍生自β-紫罗兰酮的α-卤代三烯酰胺的反应分别通过4-exo或5-exo环化提供β-或γ-内酰胺，这取决于所经历的酰胺互变异构体。对于反应性较低的二氯乙酰胺衍生物，观察到在环化之前竞争性的区域选择性甲基迁移-芳香化。