A ruthenium(II)-catalyzed asymmetric intramolecular hydroarylation assisted by a chiral transient directing group has been developed. A series of 2,3-dihydrobenzofurans bearing chiral all-carbon quaternary stereocenters have been prepared in remarkably high yields (up to 98 %) and enantioselectivities (up to >99 % ee). By this methodology, a novel asymmetric total synthesis of CB2 receptor agonist MDA7 has been successfully developed.

中文翻译：

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钌（II）催化的手性瞬态导向基团辅助的不对称惰性CH键活化。

已经开发了由手性瞬态导向基团辅助的钌（II）催化的不对称分子内氢芳基化反应。制备了一系列带有手性全碳四元立体中心的2，3-二氢苯并呋喃，具有很高的收率（高达98％）和对映选择性（高达> 99％ee）。通过这种方法，已经成功地开发了新颖的不对称的CB2受体激动剂MDA7的全合成。