B(C6F5)3‑Catalyzed Synthesis of Benzofused-Siloles

The dehydrosilylation of 2-(SiR2H)-biphenyls catalyzed by B­(C6F5)3 and a weak base forms silafluorenes with H2 as the only byproduct. Attempts to extend this approach to synthesize siloles derived from 2,2′-bithiophenes and N-Me-2-Ph-indole resulted in competing reactivity, including protodesilylation. B­(C6F5)3 also catalyzed the one-pot, two-step formation of silaindenes from aryl-alkynes by alkyne trans-hydrosilylation, followed by an intramolecular Sila-Friedel–Crafts reaction facilitated by a weak base.以三(五氟苯基)硼烷（B(C₆F₅)₃）与弱碱为催化剂，2-(SiR₂H)-联苯类化合物的脱氢硅基化反应（dehydrosilylation）可生成硅芴类化合物（silafluorenes），副产物仅为氢气。研究人员尝试将该反应体系拓展至合成源自2,2'-联噻吩与N-甲基-2-苯基吲哚的硅咯（siloles）时，出现了竞争性副反应，其中包括质子脱硅反应（protodesilylation）。三(五氟苯基)硼烷同样可催化芳基炔烃经“一锅法两步反应”合成硅茚类化合物（silaindenes）：先发生炔烃反式氢化硅基化反应（trans-hydrosilylation），随后在弱碱辅助下完成分子内硅杂傅-克反应（Sila-Friedel–Crafts reaction）。