AbstractRemote C−H functionalization of heterocyclic biaryls will be of great importance in synthesis and medicinal chemistry. Through adjusting the geometric relationship of the directing atom and target C−H bonds, two new catalytic templates have been developed to enable the functionalization of the more hindered ortho‐C−H bonds of heterobiaryls bearing directing heteroatom at the meta‐ or para‐positions, affording unprecedented site‐selectivity. The use of template chaperone also overcomes product inhibition and renders the directing templates catalytic. The utility of this protocol was demonstrated by olefination of heterocyclic biaryls with various substituents, overriding conventional steric and electronic effects. These ortho‐C−H olefinated heterobiaryls are sterically hindered and can often be challenging to prepare through aryl‐aryl coupling reactions.
摘要杂环双芳基的远程 C-H 功能化在合成和药物化学中将具有重要意义。通过调整指导原子和目标 C-H 键的几何关系,我们开发出了两种新的催化模板,可以对在元或对位上带有指导杂原子的杂环双芳基中阻碍较大的正 C-H 键进行官能化,从而获得前所未有的位点选择性。模板伴侣的使用还克服了产物抑制作用,并使定向模板具有催化作用。通过对带有各种取代基的杂环双芳基进行烯化反应,证明了这一方案的实用性,克服了传统的立体和电子效应。这些正交-C-H 烯化杂环双芳基具有立体阻碍,通常很难通过芳基-芳基偶联反应制备。