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作 者:程司堃[1] 柳文敏[1] 路丽华[1] 孙晓莉[1] 张生勇[1]
机构地区:[1]第四军医大学药学系化学教研室,陕西西安710032
出 处:《分子催化》2005年第3期208-212,i003,共6页Journal of Molecular Catalysis(China)
基 金:国家自然科学基金(20372083)资助.
摘 要:在多聚磷酸和AlCl3存在下,邻苯二甲酸酐与对二氟苯中通过Friedel-Crafts反应环化,以60%的产率生成1,4-二氟蒽醌.在碱性条件下,聚乙二醇单甲醚(HO-OPEG-OMe)与1,4-二氟蒽醌进行亲核单取代反应生成中间体F-AQN-OPEG-OMe,产率88%.然后F-AQN-OPEG-OMe与奎尼丁的锂盐再进行亲核取代反应,以91.7%的产率得到新型手性配体QD-AQN-OPEG-OMe.QD-AQN-OPEG-OMe与OsO4原位配位生成的均相催化剂在4种苯乙烯类化合物的不对称双羟化反应中表现出高的立体选择性(80%~94%ee)和催化活性(产率88%~96%).催化活性和立体选择性与Sharpless手性配体(DHQD)2AQN相当.反应结束后,加入乙醚可使配体沉淀和回收,配体的回收率均在95%~97%之间.循环使用5次,催化剂的催化活性和立体选择性无明显改变.In the presence of aluminum trichloride and polyphosphoric acid, phthalic anhydride reacted to 1, 4-difluorobezene via Friedel-Crafts and cyclization to deliver 1, 4-difluoroanthraquinone in a modified method, the yield was 60%. F-AQN-OPEG-OMe was obtained in 88% yield by nucleophilic mono-substituted by HO-OPEG-OMe and 1, 4-difluoroanthraquinone in basic medium. Then, QD-AQN-OPEG-OMe was synthesized in 91.7% yield by reaction of F-AQN-OPEG-OMe with the lithium salt of quinidine. The homogeneous catalyst that QD-AQN-OPEG-OMe complexed with osmium tetroxide in situ delivered high enantioselectivities (80%~94%ee) and catalytic reactivities (88%~96% yields) in asymmetric dihydroxylation of four styrenes, comparable to that of the homogeneous catalyst with Sharpless ligand (DHQD)_2AQN reported. This ligand was recovered almost by a simple filtration and reused for five cycles without obvious decreased enantioselectivities and catalytic activities, with 95%~97% recovery of ligand.
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