A Parham cyclization approach to diaryl-fused seven-membered ring heterocyclic ketones
作者:John Farrokh、Catherine Campos、David A. Hunt
DOI:10.1016/j.tetlet.2015.07.043
日期:2015.9
described. This work describes a novel synthesis route to diaryl-fused seven membered heterocyclic ketones through the generation of functionalized aryllithiums by bromine–lithium exchange, followed by intramolecular cyclization onto an electrophilic nitrile functional group. The resulting N-lithioimine can then be hydrolyzed to the desired ketone, generally in good yields. The order of addition of
芳基稠合的七元杂环骨架出现在各种药学上相关的化合物中。但是,仅描述了很少的制备方法。这项工作描述了一种新颖的合成路线,该路线是通过溴-锂交换生成官能化的芳基锂,然后分子内环化成亲电子腈官能团,从而生成二芳基稠合的七元杂环酮的新型合成途径。然后可以通常以高收率将所得的N-硫代亚氨基亚胺水解成所需的酮。正丁基锂的添加顺序对于该方法至关重要,事实证明,反向添加可以减轻副产物的形成并提高产率。