Department of Chemistry, University of Chicago, Chicago, IL 60637, USA.
Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Science. 2021 Apr 9;372(6538):175-182. doi: 10.1126/science.abg5526.
Mild methods to cleave the carbon-oxygen (C-O) bond in alkyl ethers could simplify chemical syntheses through the elaboration of these robust, readily available precursors. Here we report that dibromoboranes react with alkyl ethers in the presence of a nickel catalyst and zinc reductant to insert boron into the C-O bond. Subsequent reactivity can effect oxygen-to-nitrogen substitution or one-carbon homologation of cyclic ethers and more broadly streamline preparation of bioactive compounds. Mechanistic studies reveal a cleavage-then-rebound pathway via zinc/nickel tandem catalysis.
温和的方法可以切断烷基醚中的碳-氧（C-O）键，通过对这些坚固、易得的前体进行精心设计，可以简化化学合成。在这里，我们报告二溴硼烷在镍催化剂和锌还原剂的存在下与烷基醚反应，将硼插入 C-O 键中。随后的反应性可以使氧取代氮，或者使环状醚的碳-1 同系化，更广泛地简化生物活性化合物的制备。机理研究揭示了通过锌/镍串联催化的断裂-回弹途径。
