Electrochemical‐Induced Ring Transformation of Cyclic α‐(
<i>ortho</i>
‐Iodophenyl)‐β‐oxoesters
作者:Julia Strehl、Christoph Kahrs、Thomas Müller、Gerhard Hilt、Jens Christoffers
DOI:10.1002/chem.201905570
日期:2020.3.12
cycloalkanone carboxylic esters. The reaction sequence started by electrochemical reduction of the iodoarene moiety. In a mechanistic rationale, the resulting carbanionic species was adding to the carbonyl group under formation of a strained, tricyclic benzocyclobutene intermediate, which underwent carbon-carbon bond cleavage and rearrangement of the carbon skeleton by retro-aldol reaction. The scope of
环状α-(邻碘苯基)-β-氧酸酯经扩环转化而得到苯并环化的环烷酮羧酸酯。反应序列通过碘代芳烃部分的电化学还原开始。从机理上讲,生成的碳负离子物质是在形成应变的三环苯并环丁烯中间体的情况下加到羰基上的,该中间体经历了碳-碳键的断裂和碳骨架通过逆醛醇缩合反应的重排。通过转化具有不同环尺寸的环状氧代酯以中等至良好的产率产生苯并环庚酮,-壬酮和-癸酮衍生物来研究反应序列的范围。此外,无环起始原料和在碘苯基环上带有其他取代基的环状化合物已进入该反应顺序。该转化的起始原料可通过将β-氧代酸酯与苯基碘代双(三氟乙酸酯)转化而直接获得。