- A+
环氧化合物在HF/Pyridine,Bu4NH2F3,Et3N.3HF,Me3N.2HF,SiF4,DAST等亲核试剂作用下开环,生成邻位氟代的醇。
HF/Pyridine在温和的条件下高产率的使环氧开环,有些底物的区域选择性和立体选择性也不错。
【Ayi, A, I;Remli, M; Guedj, R. Tetrahedron. Lett. 1981, 22, 1505】
SiF4是更温和的一个试剂,很多官能团如双键,醚键,C-Si键在这个条件下也不会断裂。
【Begum, C, G; Charlon, C; Coulombeau, C; Luu, D, C. J.Fluorine. Chem. 1976, 8, 531.】
【 Kanemoto, S; Shimizu,M; Yoshioka, H. Tetrahedron. Lett. 1987, 28, 6313.】
反应实例
The mixture of epoxide (1.56 g, 10 mmol) and Me3N.2HF(1.48 g, 15 mmol) in CH2Cl2(50 mL) was heated to reflux for 2 hours. The resulting mixture was extracted with CH2Cl2and washed with aq. K2CO3 solution and brine, the organicphase was dried over Na2SO4 and the solvent was removedunder reduced pressure. The residue waspurified by column chromatography on silica gel to give the desired product (1.1 g, 63%).
【Amri, H; El Gaied, M, M. J.Fluorine. Chem. 1990, 46, 75.】
本文非原创内容,版权归原作者所有,如涉及版权问题,请联系本号删除。
目前评论:0