Thanks to Pd(II)‐catalysis, an efficient synthesis of unsaturated macrocycles is achieved by [3+6+3+6] condensation of cyclic ethers with aryl α‐diazo‐β‐ketoesters. The presence of the electron‐rich aryl ester moieties forbids the use of dirhodium complexes as these diazo decomposition catalysts provoke unforeseen intermolecular C_sp2‐H insertion reactions that derail the targeted reactivity. However, with Pd(acac)₂, using high concentration conditions (1 M), a variety of 18‐membered macrocycles (16 examples) is afforded with both aryl and alkyl diazo reagents. Catalyst selection for either electrophilic aromatic substitution (Rh) or ylide (Pd) pathways are explained by computational approaches

中文翻译：

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Pd催化的芳基α-重氮-β-酮酯的[3+6+3+6]大环化反应

借助 Pd(II) 催化，通过环醚与芳基 α-重氮-β-酮酯的 [3+6+3+6] 缩合实现了不饱和大环化合物的有效合成。富电子芳基酯部分的存在禁止使用二铑配合物，因为这些重氮分解催化剂会引发不可预见的分子间 C_sp2-H 插入反应，从而破坏目标反应性。然而，使用 Pd(acac)₂，在高浓度条件 (1 M) 下，芳基和烷基重氮试剂均可提供多种 18 元大环化合物（16 个实例）。通过计算方法解释了亲电芳香取代 (Rh) 或叶立德 (Pd) 途径的催化剂选择