Gardner Bradley W, Lalic Gojko
Department of Chemistry, University of Washington, Seattle, WA, USA.
Nat Chem. 2025 Jul 24. doi: 10.1038/s41557-025-01854-4.
Organoboron compounds are important intermediates in organic synthesis, commonly used in metal-catalysed cross-coupling reactions. Their unique reactivity also allows modifications of their carbon framework with preservation of the valuable boryl group. Traditionally, these homologation reactions have been confined to the formation of alkyl boron compounds via C(sp) insertion into a C-B bond. However, recent advancements in C(sp)-insertive homologation highlight the potential of these reactions in synthesizing complex alkenes, despite current limitations in scope and control of the alkene geometry. Here we demonstrate a catalytic C(sp)-insertive homologation for the regio- and diastereoselective synthesis of complex trisubstituted diborylalkenes from simple alkylboranes and alkynyl boronic esters. Our work demonstrates a broad reaction scope and application of the resulting products in modular and stereoselective synthesis of highly substituted alkenes. Furthermore, we provide evidence supporting a unique mechanism responsible for the excellent stereoselectivity observed in the reaction.
有机硼化合物是有机合成中的重要中间体，常用于金属催化的交叉偶联反应。它们独特的反应活性还允许在保留有价值的硼基的同时对其碳骨架进行修饰。传统上，这些同系化反应仅限于通过C(sp)插入C-B键来形成烷基硼化合物。然而，C(sp)插入同系化的最新进展突出了这些反应在合成复杂烯烃方面的潜力，尽管目前在烯烃几何结构的范围和控制方面存在局限性。在此，我们展示了一种催化C(sp)插入同系化反应，可从简单的烷基硼烷和炔基硼酸酯区域和非对映选择性地合成复杂的三取代二硼基烯烃。我们的工作展示了广泛的反应范围以及所得产物在高度取代烯烃的模块化和立体选择性合成中的应用。此外，我们提供了证据支持一种独特的机理，该机理导致了反应中观察到的优异立体选择性。
