Cu(I)-catalyzed reaction of o-bromobenzaldehydes with β-ketoesters using Cs2CO3 as a base and 2-picolinic acid as an additive proceeds under mild conditions and gives access to substituted naphthalenes in a single step with yields ranging from 71 to 86%. The new annulation process relies on a domino Knoevenagel condensation/C-arylation/1,2-addition/carboxylic acid cleavage. The annulation can also be achieved with o-iodobenzaldehyde.
以 Cs2CO3 为碱和
2-吡啶甲酸为添加剂,Cu(I)催化
邻溴苯甲醛与 δ
酮酯的反应在温和条件下进行,一步即可得到取代的
萘,产率为 71% 至 86%。新的环化工艺依赖于多米诺 Knoevenagel 缩合/芳香化/1,2-加成/
羧酸裂解。邻
碘苯甲醛也可实现环化。