Investigation of the Pyridinium Ylide—Alkyne Cycloaddition as a Fluorogenic Coupling Reaction
作者:Simon Bonte、Ioana Ghinea、Rodica Dinica、Isabelle Baussanne、Martine Demeunynck
DOI:10.3390/molecules21030332
日期:——
cycloaddition of pyridinium ylides with alkynes was investigated under mild conditions. A series of 13 pyridinium salts was prepared by alkylation of 4-substituted pyridines. Their reactivity with propiolic ester or amide in various reaction conditions (different temperatures, solvents, added bases) was studied, and 11 indolizines, with three points of structural variation, were, thus, isolated and
在温和条件下研究了吡啶鎓吡啶与炔的环加成反应。通过4-取代吡啶的烷基化制备一系列13个吡啶鎓盐。研究了它们在各种反应条件(不同温度,溶剂,添加的碱)下与丙酸酯或酰胺的反应性,从而分离和表征了11种具有三个结构变化点的吲哚嗪。当从相应的吡啶鎓盐就地生成的吡啶鎓内鎓盐和炔烃(X,Z =酯,酰胺,CN,羰基等)上均存在吸电子基团时,可获得最高的收率。吸电子取代基降低了吡啶鎓盐的酸解离常数(pKa),使环加成反应在室温下在水性缓冲液中于pH 7.5进行。