Pali Pragya, Yadav Dhananjay, Sahoo Subash C, Shankar Singh Maya
Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
Department of Chemistry, Panjab University, Chandigarh 160014, India.
J Org Chem. 2022 Sep 16;87(18):12342-12351. doi: 10.1021/acs.joc.2c01581. Epub 2022 Aug 29.
A concise and practical one-pot sustainable approach for expedient synthesis of 2-arylimino-2-chromenes by two-component cascade [4 + 2] annulative coupling of easily available 2-hydroxybenzaldehydes with β-ketothioamides has been developed in good yields for the first time. Remarkably, metal- and additive-free conditions, use of simple KCO as a mild base, open atmosphere, exclusive regioselectivity, step/atom economy, nonhazardous reagents, and easy purification are added characteristics to the strategy. This annulative protocol will not only provide an efficient method to access diverse chromene scaffolds, but also enrich the research domain of β-ketothioamides.
首次开发了一种简洁实用的一锅法可持续方法，通过易得的2-羟基苯甲醛与β-酮硫代酰胺的两组分级联[4 + 2]环化偶联反应，以良好的产率方便地合成2-芳基亚氨基-2-色烯。值得注意的是，该策略还具有无金属和添加剂的条件、使用简单的碳酸钾作为温和碱、开放的反应氛围、独特的区域选择性、步骤/原子经济性、无危险试剂以及易于纯化等特点。这种环化反应方案不仅将提供一种获得多种色烯骨架的有效方法，还将丰富β-酮硫代酰胺的研究领域。
