Zhang Shan, Wunsch Jonas F, Rudolph Matthias, Rominger Frank, Hashmi A Stephen K
Organisch-Chemisches Institut, Heidelberg University, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.
Angew Chem Int Ed Engl. 2024 Dec 9;63(50):e202406856. doi: 10.1002/anie.202406856. Epub 2024 Nov 7.
The use of diaryl-substituted vinyl boronates, a class of chemical building blocks with well-known synthetic utility, is principally limited by the difficulty faced in their preparation. Herein, we present a convenient synthetic strategy based on a gold-catalyzed Hiyama arylation of (Z)-β-(borylvinyl)silanes, which are easily accessible by hydroboration of silylalkynes. By exploiting the highly electronegative nature of the gold(III) intermediate (which is accessed by light-assisted oxidation using aryl diazonium salts), a selective activation of the silyl group in the presence of the boron moiety is achieved. This opens a route to selectively synthesize diaryl-substituted vinyl boronates. The reaction shows a broad substrate range, excellent functional group tolerance, and perfect chemoselectivity. Experimental studies and density functional theory (DFT) calculations allowed us to elucidate the mechanism of the reaction. The synthetic potential was demonstrated by downstream transformations providing a facile route to bifunctional phenanthrenes and triaryl-substituted olefins.
二芳基取代的乙烯基硼酸酯是一类具有众所周知的合成效用的化学结构单元，其使用主要受到制备过程中所面临困难的限制。在此，我们提出了一种基于金催化的（Z）-β-（硼基乙烯基）硅烷的日向芳基化反应的便捷合成策略，（Z）-β-（硼基乙烯基）硅烷可通过硅基炔烃的硼氢化反应轻松获得。通过利用金（III）中间体的高电负性（通过芳基重氮盐的光辅助氧化获得），在硼部分存在的情况下实现了硅基的选择性活化。这为选择性合成二芳基取代的乙烯基硼酸酯开辟了一条途径。该反应显示出广泛的底物范围、出色的官能团耐受性和完美的化学选择性。实验研究和密度泛函理论（DFT）计算使我们能够阐明反应机理。通过下游转化展示了合成潜力，为双功能菲和三芳基取代的烯烃提供了一条便捷途径。
