Welwistatin support studies: expansion and limitation of aryllead(IV) coupling reactions.
Welwistatin support studies: expansion and limitation of aryllead(IV) coupling reactions.
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Welwistatin 支持研究：芳基铅 (IV) 偶联反应的扩展和限制。
DOI：
10.1021/jo071156l
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Konopelski,JosephP
中科院分区：
文献类型：
--
作者：
Xia,Jibo;Brown,LaurenE;Konopelski,JosephP
描述了最近关于韦维他汀系统的全合成的支持研究。目标步骤涉及铅介导的芳基化的空间要求的芳基基团和碳酸偶联伙伴，以建立高度拥挤的四环核心结构。7型β-酮酯和β-酮腈成功地被卤素-硼-铅交换序列产生的各种邻位和间位取代的芳基铅化合物芳基化。化合物15、19和25的烯醇化物，每个都带有与芳基化位点相邻的全碳季中心，不能偶联。
Recent support studies on the total synthesis of the welwistatin system are described. The target step involves lead-mediated arylation of sterically demanding aryl groups and carbon acid coupling partners in order to establish the highly congested tetracyclic core structure. Type7β-ketoesters and β-ketonitriles were successfully arylated with a variety of ortho- and meta-substituted aryllead compounds generated by a halogen−boron−lead exchange sequence. The enolates of compounds15,19, and25, each bearing all-carbon quaternary centers adjacent to the arylation site, failed to couple.