Catalytic Enantioselective Inverse-Electron Demand 1,3-Dipolar Cycloaddition Reactions of Nitrones with Alkenes
作者:Klaus B. Simonsen、Pau Bayón、Rita G. Hazell、Kurt V. Gothelf、Karl Anker Jørgensen
DOI:10.1021/ja983915a
日期:1999.4.1
catalytic enantioselective 1,3-dipolar cycloaddition reaction of nitrones, activated by chiral Lewis acids, with electron-rich alkenes has been developed. The nitrones are activated by various chiral 2,2‘-dihydroxy-1,1‘-binaphthyl (BINOL)-AlMe complexes, and it has been found that 3,3‘-diaryl-BINOL-AlMe complexes catalyze a highly regio-, diastereo-, and enantioselective 1,3-dipolar cycloaddition reaction
已经开发了由手性路易斯酸活化的硝酮与富电子烯烃的催化对映选择性 1,3-偶极环加成反应的一般反应方案。硝酮被各种手性 2,2'-二羟基-1,1'-联萘 (BINOL)-AlMe 络合物活化,并且已经发现 3,3'-二芳基-BINOL-AlMe 络合物催化高度区域性、芳族硝酮与乙烯基醚的非对映选择性和对映选择性 1,3-偶极环加成反应,得到异恶唑烷的外非对映异构体,de's 高达 >90%,ee 高达 97%。该反应在不同条件下用不同的硝酮和乙烯基醚(和烯烃)进行了研究,并提出了一般的合成程序。基于催化剂的线性立体化学效应讨论了反应机理,