作者:Olesia Zaitceva、Valérie Bénéteau、Dmitry S. Ryabukhin、Benoit Louis、Aleksander V. Vasilyev、Patrick Pale
DOI:10.1002/cctc.201901384
日期:2020.1.8
Acidic zeolites, especially faujasites, efficiently promote the intramolecular cyclization of aryl propynoates and propynethioates, which produces coumarins and thiocoumarins, usually in high yields. Comparison with homogeneous Lewis or BrØnsted acids and with heterogeneous related sieve materials revealed the prevalence of zeolites exhibiting large cage‐type pores (H‐USY) for such cyclizations. Various
酸性沸石,尤其是八面沸石,有效地促进了芳基丙酸酯和丙炔硫代酸酯的分子内环化,通常可高产率地产生香豆素和硫代香豆素。与均相的路易斯酸或布朗斯台德酸以及与异质相关的筛子材料进行比较,发现此类环化反应中普遍存在具有大笼型孔(H-USY)的沸石。事实证明,各种取代基均与环化过程兼容,从而导致了各种取代的香豆素和硫代香豆素(20个实例,占30%至99%)。