Palladium-Catalyzed Aryne Insertion/Arene Dearomatization Domino Reaction: A Highly Chemoselective Route to Spirofluorenes

A palladium(0)-catalyzed
dearomatizing [3+2] spiroannulation of
naphthalene-based biaryls with arynes has been developed for the rapid
construction of spirofluorene architectures. This reaction was realized
by carbopalladation of aryne to generate an arylpalladium species,
followed by termination with naphthalene dearomatization, which is
a sharp contrast to the conventional C–H functionalization
approach. Mechanistic studies revealed that the arene dearomatization
might take place through a 5-exo-trig spiroannulation and distal-hydride
elimination Heck-type pathway.

本研究开发了一种钯(0)催化的萘基联芳烃与芳炔(aryne)的脱芳构化[3+2]螺环化反应，可快速构建螺芴骨架。该反应通过芳炔的碳钯化生成芳基钯物种，随后经萘的脱芳构化实现反应终止，这与传统的C-H官能化策略形成鲜明对比。机理研究表明，该芳烃脱芳构化过程可能通过5-外向三中心螺环化与远端氢消除型Heck类反应路径进行。