Asymmetric Epoxidation of 1,4-Naphthoquinones Catalyzed by Guanidine–Urea Bifunctional Organocatalyst
作者:Masaki Kawaguchi、Katsuhiro Nakano、Keisuke Hosoya、Tatsuya Orihara、Masahiro Yamanaka、Minami Odagi、Kazuo Nagasawa
DOI:10.1021/acs.orglett.8b00641
日期:2018.5.18
An enantioselective nucleophilic epoxidation of 2-substituted 1,4-naphthoquinones in the presence of a newly developed guanidine–bisurea bifunctional organocatalyst with tert-butyl hydroperoxide (TBHP) as an oxidant is presented. 1,4-Naphthoquinones bearing substituents at C6, C7, and C2 were available for the reaction, and the corresponding epoxides were obtained with 88:12–95:5 er in 71–98% yields
提出了在新开发的胍-双脲双功能有机催化剂存在下,以叔丁基氢过氧化物(TBHP)为氧化剂的2-取代的1,4-萘醌的对映选择性亲核环氧化反应。在C6,C7和C2处带有取代基的1,4-萘醌可用于该反应,并以88:12–95:5 er的产率得到71-98%的相应环氧化物。DFT计算表明,催化剂9k的末端Ar基团中的C2和C6处的取代基在控制立体化学结果中起关键作用。