electron-deficient olefins gave substituted hydrocarbazoles in up to 99% yield and 94% ee. This reaction was catalyzed by a novel chiral holmium(III) complex. Alkylation of the cycloadduct gave a tricyclic compound with four continuous chiral centers, one of which was a quaternary carbon.
3- [1-(甲
硅烷氧基)
乙烯基]
吲哚与缺电子烯烃之间的催化和不对称环加成反应以最高99%的收率和94%ee的产率得到取代的
咔唑。该反应由新型手性(III)配合物催化。环加合物的烷基化得到具有四个连续手性中心的
三环化合物,其中一个是季碳。