通过将分子间的阿道尔顿缩合反应与随后的分子内碱基促进的均相芳族取代反应相结合,已经实现了一种不寻常的苯环化反应。这种新颖的级联反应为在DMSO中存在Cs 2 CO 3的情况下从2-卤代苯甲醛和吲哚-2-酮的各种萘稠合的吲哚提供了直接的方法。吲哚-2-酮作为新的和内部的电子供体的烯醇被证明可以引发分子内自由基脱卤偶联。
Direct One-Pot Synthesis of Naphthoxindoles from 4-Bromooxindoles by Suzuki-Miyaura Coupling and Aldol Condensation Reactions
作者:Kyeong-Yong Park、Bum Tae Kim、Jung-Nyoung Heo
DOI:10.1002/ejoc.201301242
日期:2014.1
An efficient one-pot synthesis of naphthoxindoles by using 4-bromoindolin-2-ones and 2-formylphenylboronic acids has been developed. The coupling reaction proceeds in good to excellent yields under microwave irradiation through a Suzuki–Miyaura coupling and an aldolcondensation cascade reaction. In addition, this protocol permits the facile construction of naphthoxindoles through an expanded scope
base-promoted homolytic aromatic substitution. This novel cascade reaction provides a straightforward approach toward various naphtho-fused oxindoles from 2-halobenzaldehydes and indolin-2-ones in the presence of Cs2CO3 in DMSO. The enolates of indolin-2-ones as new and internal electron donors have been demonstrated to initiate intramolecular radical dehalogenative coupling.
通过将分子间的阿道尔顿缩合反应与随后的分子内碱基促进的均相芳族取代反应相结合,已经实现了一种不寻常的苯环化反应。这种新颖的级联反应为在DMSO中存在Cs 2 CO 3的情况下从2-卤代苯甲醛和吲哚-2-酮的各种萘稠合的吲哚提供了直接的方法。吲哚-2-酮作为新的和内部的电子供体的烯醇被证明可以引发分子内自由基脱卤偶联。