Catalytic generation of <i>ortho</i>-quinone dimethides <i>via</i> donor/donor rhodium carbenes
作者:Mingchun Gao、Jose M. Ruiz、Emily Jimenez、Anna Lo、Croix J. Laconsay、James C. Fettinger、Dean J. Tantillo、Jared T. Shaw
DOI:10.1039/d3sc00734k
日期:——
cycloaddition reactions with high diastereo- and regio-selectivity. This is one of the few examples of catalytic generation of o-QDM without the intermediacy of a benzocyclobutene and represents one of the mildest, ambient temperature processes to access these useful intermediates. This proposed mechanism is supported by DFT calculations. Moreover, the methodology was applied to the synthesis of (±)-isolariciresinol
经过工程改造以经过 1,4-C-H 插入以产生苯并环丁烯的底物导致了一种新的消除反应,以产生经过 Diels-Alder 或异种-Diels-Alder 环加成反应的邻醌二甲醚 (o-QDM) 中间体。类似的苄基缩醛或醚完全避免了 C-H 插入途径,并且在氢化物转移后,在环境温度下发生脱芳构化消除反应,形成 o-QDM。所得的二烯经过各种环加成反应,具有高非对映和区域选择性。这是为数不多的在没有苯并环丁烯中介的情况下催化生成 o-QDM 的例子之一,并且代表了获得这些有用中间体的最温和的环境温度过程之一。DFT 计算支持这种提出的机制。此外,该方法应用于 (±)-isolariciresinol 的合成,总产率为 41%。