Tandem Cyclization/Hydroarylation of α,ω-Dienes Triggered by Scandium-Catalyzed C–H Activation

A highly regio- and diastereoselective cyclization/hydroarylation reaction of 1,5- and 1,6-dienes with aromatic ethers and tertiary anilines was established by a cationic 2-picoline-tethered-half-sandwich scandium alkyl catalyst, which constitutes a process for producing a diverse array of cis-1,3-disubstituted arylated and trans-1,2-disubstituted benzylated methylcyclopentane derivatives in one step with 100% atom-efficiency. Furthermore, a mechanism involving a scandium-catalyzed aromatic ortho-C–H activation and alkene-insertion cascade was also proposed.

本研究开发了由阳离子型2-甲基吡啶（2-picoline）配位半夹心钪烷基催化剂介导的1,5-二烯烃与1,6-二烯烃分别与芳香醚、叔苯胺发生区域及非对映选择性环化/氢芳基化反应的方法；该方法可一步合成一系列结构多样的顺式-1,3-二取代芳基化与反式-1,2-二取代苄基化甲基环戊烷衍生物，且实现了100%原子经济性。此外，本研究还提出了涉及钪催化芳香邻位C-H活化与烯烃插入级联反应的机理。