Rare-Earth Silylamide-Catalyzed Selective Dimerization of Terminal Alkynes and Subsequent Hydrophosphination in One Pot
作者:Kimihiro Komeyama、Tomonori Kawabata、Katsuomi Takehira、Ken Takaki
DOI:10.1021/jo0509206
日期:2005.9.1
Rare-earth silylamides, Ln[N(SiMe3)2]3 (Ln = Y, La, Sm), catalyzed regio- and stereoselective dimerization of terminal alkynes in the presence of amine additives to give conjugated enynes in high yields. The additives played a crucial role to depress the oligomerization and to control the regio- and stereochemistry of the dimerization. Thus, the selectivity for (Z)-head-to-head enynes was increased
稀土甲硅烷基酰胺Ln [N(SiMe 3)2 ] 3(Ln = Y,La,Sm),在胺添加剂存在下催化末端炔烃的区域和立体选择性二聚,从而以高收率得到共轭烯炔。添加剂在抑制低聚和控制二聚化的区域和立体化学方面起着至关重要的作用。因此,对(Z头对头烯炔以叔<仲<伯胺添加剂的顺序增加。另一方面,观察到相反的顺序以形成头尾二聚体。当对α,ω-二炔进行二聚时,通过双二聚以令人满意的产率得到了非常新颖的环状双亚炔化合物。另外,该系统的应用允许随后用二苯基膦将原位生成的烯炔进行氢磷酸化,从而在氧化后处理后以极高的收率产生作为唯一产物的1-膦基-1,3-二烯。