Oxazole Synthesis by Sequential Asmic-Ester Condensations and Sulfanyl–Lithium Exchange–Trapping
作者:Louis G. Mueller、Allen Chao、Embarek Alwedi、Maanasa Natrajan、Fraser F. Fleming
DOI:10.1021/acs.orglett.1c00288
日期:2021.2.19
Oxazoles are rapidly assembled through a sequential deprotonation–condensation of Asmic, anisylsulfanylmethylisocyanide, with esters followed by sulfanyl–lithium exchange–trapping. Deprotonating Asmic affords a metalated isocyanide that efficiently traps esters to afford oxazoles bearing a versatile C-4 anisylsulfanyl substituent. Interchange of the anisylsulfanyl substituent is readily achieved through
恶唑通过 Asmic、茴香硫基甲基异氰化物与酯的顺序去质子化 - 缩合快速组装,然后是硫烷基 - 锂交换 - 捕获。去质子化 Asmic 可提供金属化异氰化物,可有效捕获酯类,从而提供带有通用 C-4 苯硫基取代基的恶唑。通过一流的硫-锂交换-亲电捕获序列可以很容易地实现茴香硫基取代基的交换,其多功能性在生物活性天然产物链绿素的三步合成中得到了说明。