Rhodium-catalysed reactions of N-benzyl- or
N-alkyl-aminoalkenes (6) with
H2/CO can give cyclic amines (7) (7–13 ring
size) in good to excellent yields when BIPHEPHOS is used as a ligand.
Hydrogenation of the aminoalkene becomes a competing reaction for the smaller
rings but can be overcome by using a H2/CO gas ratio
of 1 : 5. Reactions of 2-alkenyloxybenzylamines (13) gave 9-, 12- and
17-membered rings (14) in 30–40% yield, but dimer formation (16)
and/or hydrogenation were competing reactions. Similar reactions of
alkenylamides and ortho-alkenylanilines gave only
non-cyclized amino aldehydes as products in low isolated yields.
在铑催化下,N-苄基或
N-苄基或 N-烷基氨基烯烃 (6) 与
H2/CO 催化反应,可以得到环胺 (7)(7-13 个环)。
大小),而且产量极高。
对于较小的环,氨基烯的氢化会成为一个竞争反应。
但可以通过使用 H2/CO 气体比率为
为 1 : 5。2- 烯氧基苄胺 (13) 的反应生成了 9-、12- 和
17 元环 (14),收率为 30-40%,但二聚体的形成 (16)
和/或氢化是竞争反应。类似的反应还有
烯酰胺和邻位烯基苯胺的类似反应只能生成
非环化氨基醛作为产物,分离产率较低。