W(CO)<sub>5</sub>(L)-Catalyzed Endo-Selective Cyclization of Allenyl Silyl Enol Ethers: An Efficient Method for the Cyclopentene Annulation onto α,β-Unsaturated Ketones
作者:Tomoya Miura、Koichi Kiyota、Hiroyuki Kusama、Kooyeon Lee、Hyunseok Kim、Sunggak Kim、Phil Ho Lee、Nobuharu Iwasawa
DOI:10.1021/ol034365a
日期:2003.5.1
undergo W(CO)(5)(L)-catalyzed 5-endo cyclization to give the corresponding cyclopentene derivatives in good yield. Furthermore, this novel W(CO)(5)(L)-catalyzed cyclization of allenyl silyl enol ethers proceeds in a 6-endo manner when 5-siloxy-1,2,5-trienes are employed as a substrate. In these reactions, effective electrophilic activation of allenyl compounds for attack by silyl enol ethers is achieved
[反应:参见正文]在叔丁基二甲基甲硅烷基三氟甲磺酸酯和二甲基硫醚存在下,铟介导的α,β-不饱和酮的烯丙基化反应生成6-甲硅烷氧基-1,2,5-三烯,并经历W(CO)(5) (L)-催化的5-内-环化以良好的产率得到相应的环戊烯衍生物。此外,当使用5-甲硅烷氧基1,2,5-三烯作为底物时,这种新型的W(CO)(5)(L)催化的烯丙基甲硅烷基烯醇醚的环化反应以6-内酯方式进行。在这些反应中,使用催化量的W(CO)(6)可实现对烯丙基化合物的有效亲电子活化,以使其被甲硅烷基烯醇醚侵蚀。