我们在这里介绍关于叔丁醇钾促进的2-炔基苯基炔丙基醚的环化反应以产生两种不同类型的杂环的结果:3-苄基-2-炔基苯并呋喃和12 H-苯并环戊并苯并[ b ]呋喃。叔丁基钾有效地环化了一系列官能化的2-炔基苯基炔丙基醚-丁氧化物制得相应产物。优化的反应条件可耐受多种官能团,包括富电子,贫电子和N杂环底物。通过控制溶剂和温度获得选择性的产物形成。当在室温下使用THF时,只能获得3-苄基-2-炔基苯并呋喃衍生物,而在60°C下使用DMF时,则可以选择性地生成12 H-苯并环戊烯[ b ]苯并呋喃。
The use of N‐(p‐chlorophenyl)methylbenzoxazole‐2‐thione as a sulfur‐atom donor enables the catalytic [2+2+1] cycloaddition of diynes in wet DMF at 80 °C when open to air, thus affording diverse fused thiophenes with good yields and wide functional‐group compatibility. A plausible mechanism, involving a cationic ruthenacycle intermediate, was also proposed on the basis of several control experiments
A novel oxygen-atom-transfer process enables the catalytic [2 + 2 + 1] synthesis of bicyclic furans from alpha,omega-diynes with DMSO. [CpRu(AN)(3)]PF6 catalyzed the transfer oxygenative cyclization of diynes with aryl terminal groups, while those of diynes with alkyl terminal groups were effectively promoted by the corresponding Cp* complex. A mechanism for bicyclic furan formation via a ruthenacyclopentatriene was proposed on the basis of both experimental and theoretical studies.