2<i>H</i>-Chromene-3-carboxylic Acid Synthesis via Solvent-Controlled and Rhodium(III)-Catalyzed Redox-Neutral C–H Activation/[3 + 3] Annulation Cascade
作者:Zhi Zhou、Mengyao Bian、Lixin Zhao、Hui Gao、Junjun Huang、Xiawen Liu、Xiyong Yu、Xingwei Li、Wei Yi
DOI:10.1021/acs.orglett.8b01477
日期:2018.7.6
redox-neutral synthesis of 2H-chromene-3-carboxylic acids from N-phenoxyacetamides and methyleneoxetanones has been realized via a solvent-controlled and rhodium(III)-catalyzed C–H activation/unusual [3 + 3] annulation sequence. This transformation represents the first example of using an α-methylene-β-lactone unit as the three-carbon source in transition-metal-catalyzed C–H activations through selective alkyl
通过溶剂控制和铑(III)催化的C–H活化/不寻常的[3 + 3]环化反应,已经实现了由N-苯氧基乙酰胺和亚甲基氧杂环丁烷高效合成和氧化还原中性的2 H-苯甲基-3-羧酸顺序。这种转变代表了使用α-亚甲基-β-内酯单元作为过渡碳催化的CH活化(通过选择性烷基C-O键断裂)中的三碳源的第一个例子。合成应用和机理细节,包括2 H-苯并-3-羧酸的进一步衍生化,五元罗丹环的分离和鉴定以及合理的Rh(III)-Rh(V)的理论研究-Rh(III)过程,也已经讨论过。