Facile synthesis of 4-acetyl-coumarins, -thiocoumarin and -quinolin-2(1H)-one via very high α-regioselective Heck coupling on tosylates
作者:Sergio Valente、Gilbert Kirsch
DOI:10.1016/j.tetlet.2011.04.033
日期:2011.7
An efficient synthesis of a series of methyl ketones at the C4 position of coumarins, coumarin-containing heterocycles and analogous scaffolds is reported via very high α-regioselective Heck coupling using tosylates and in very high yields. Although α-regioselectivity in Heck coupling can be obtained with triflates as substrates, tosylates are less toxic, less expensive and, importantly, more stable
据报道,通过使用甲苯磺酸盐的非常高的α-区域选择性Heck偶联,并以非常高的收率,在香豆素,含香豆素的杂环和类似支架的C4位有效合成了一系列甲基酮。尽管可以用三氟甲磺酸酯作为底物获得Heck偶联中的α-区域选择性,但是甲苯磺酸盐的毒性较小,价格较低并且重要的是更稳定。