Catalytic asymmetric allylation of ketones and a tandem asymmetric allylation/diastereoselective epoxidation of cyclic enones
Catalytic asymmetric allylation of ketones and a tandem asymmetric allylation/diastereoselective epoxidation of cyclic enones
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DOI：
10.1021/ja047758t
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发表时间：
2004-10-06
影响因子：
15
通讯作者：
Walsh, PJ
中科院分区：
文献类型：
--
作者：
Kim, JG;Waltz, KM;Walsh, PJ
报道了以四异丙醇钛、BINOL、2-丙醇添加剂和四烯丙基锡烷为烯丙化剂催化酮类不对称烯丙化反应的简单方法。各种酮底物，包括苯乙酮衍生物和α、β不饱和环烯酮，反应生成叔烯丙基醇，产率高（67-99%），对映选择性高（通常为80%）。还介绍了一种新的单锅对映选择性烯丙基化/非对映选择性环氧化反应。因此，在完成烯丙基对共轭环烯酮的加成后，加入了1等量的叔丁基过氧化氢，并随后对烯丙基双键进行定向环氧化，从而获得具有高非对映选择性的环氧醇。
A simple procedure is reported for the catalytic asymmetric allylation of ketones, utilizing titanium tetraisopropoxide, BINOL, 2-propanol additive, and tetraallylstannane as allylating agent. A variety of ketone substrates, including acetophenone derivatives and alpha,beta-unsaturated cyclic enones, reacted to form tertiary homoallylic alcohols in good yields (67-99%) and with high levels of enantioselectivity (generally >80%). A novel one-pot enantioselective allylation/diastereoselective epoxidation has also been introduced. Thus, upon completion of the allyl addition to conjugated cyclic enones, 1 equiv of tert-butyl hydroperoxide is added and the directed epoxidation of the allylic double bond ensues to afford the epoxy alcohol with high diastereoselectivity.