Department of Chemistry , University of Minnesota , 207 Pleasant Street SE , Minneapolis , Minnesota 55455 , United States.
Org Lett. 2019 Apr 19;21(8):2615-2619. doi: 10.1021/acs.orglett.9b00595. Epub 2019 Apr 10.
Hydroxy-containing cyclic ethers react with thermally generated benzynes to produce aryl ethers. Diverse reactivity was observed. Cleavage of the cyclic ether was involved in most of the pathways. The transformations are rationalized via initial formation of oxonium ion-containing 1,3-zwitterions arising from preferential nucleophilic attack on the benzyne by the ether oxygen. Pinacol-like rearrangements, including ring expansion, to yield aldehydes or ketones and oxirane fragmentations to generate aryl enol ethers were main competing events.
含羟基的环状醚与热生成的苯炔反应生成芳基醚。观察到了不同的反应性。在大多数途径中都涉及到环状醚的裂解。这些转化可以通过优先由醚氧对苯炔进行亲核攻击而形成含氧鎓离子的 1,3-两性离子来合理化。包括扩环在内的频哪醇重排反应、生成醛或酮以及环氧乙烷的断裂反应生成芳基烯醇醚是主要的竞争反应。
