In recent decades, C–H borylation has undergone rapid development and has become one of the most important and efficient methods for the synthesis of organoboron compounds. Although transition-metal catalysis dominates C–H borylation, the metal-free approach has emerged as a promising alternative strategy. This article briefly summarizes the history of metal-free aromatic C–H borylation, including early reports on electrophilic C–H borylation and recent progress in metal-free catalytic intermolecular C–H borylation; it also highlights our recent work on BF3·Et2O-catalyzed C2–H borylation of hetarenes. Despite these recent advances, comprehensive mechanistic studies on various metal-free catalytic aromatic C–H borylations and novel processes with a wider substrate scope are eagerly expected in the near future.

中文翻译：

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无金属催化芳烃 C-H 硼化

近几十年来，C-H硼化得到了快速发展，已成为合成有机硼化合物最重要、最有效的方法之一。尽管过渡金属催化在 C-H 硼化反应中占主导地位，但无金属方法已成为一种有前景的替代策略。本文简要总结了无金属芳香族C-H硼化的历史，包括亲电C-H硼化的早期报道和无金属催化分子间C-H硼化的最新进展；它还强调了我们最近在 BF3·Et2O 催化的杂环烃的 C2-H 硼酸化方面的工作。尽管最近取得了这些进展，但人们热切期待在不久的将来对各种无金属催化芳族 C-H 硼化和具有更广泛底物范围的新工艺进行全面的机理研究。