The transformation of α-silylated aldehydes 3a-h into the propargylsilanes 5a-k and the (Z)-allylsilane 6 is described. The readily available tert-butylimine 1 of acetaldehyde is silylated and alkylated in a one-pot procedure to obtain the α-silylated aldehydes 3a-h after hydrolysis of the imine moiety in 77-96% yield. C-1 homologation by the Corey-Fuchs method gave 1,1-dibromoallylsilanes 4a-h in 70-96% yields which can be transformed into the mono- and disubstituted propargylsilanes 5a-k in 33-95% yield. Hydrogenation of the propargylsilanes e.g. 5e with Ni(OAc)2/NaBH4 gives the (Z)-allylsilane 6a in 80% yield.
本文介绍了将δ-
硅烷化醛 3a-h 转化为
丙炔基
硅烷 5a-k 和(Z)-
烯丙基
硅烷 6 的过程。
乙醛的叔丁基
亚胺 1 易于获得,通过
硅烷化和烷基化的一锅程序,在
亚胺分子
水解后得到δ-
硅烷化醛 3a-h,收率为 77-96%。通过科里-富克斯法进行 C-1 同族反应,可得到 1,1-二
溴烯丙基
硅烷 4a-h,收率为 70-96%,这些
硅烷可转化为单取代和二取代的
丙炔基
硅烷 5a-k,收率为 33-95%。用 Ni(
OAc)2/NaBH4 对
丙炔基
硅烷(如 5e)进行
氢化,可得到(Z)-
烯丙基
硅烷 6a,收率为 80%。