chlorodiphenylphosphine. This PN‐ligand was converted into (R)‐(η5‐(Sp)‐1‐(α‐dicyclohexylphosphinoethyl)‐2‐(diphenylphosphino)cyclopentadienyl)(η4‐tetraphenylcyclobutadiene)cobalt(I), a PP‐ligand (Rossiphos), by stereospecific amine‐phosphine exchange using HPCy2. These air‐stable P−N and P−P complexes are the first examples of a new class of bulky planar chiral ligands for application in asymmetric catalysis
从(η开始5 -acetylcyclopentadienyl)(η 4 -tetraphenylcyclobutadiene)
钴(I),对映体选择性高(99%EE)(小号)-
CBS催化酮还原,接着立体特异性醇-
叠氮化物交换,
叠氮化物还原和dimethyllation得到(- [R ) - (η 5 -α- ñ,ñ -dimethylaminoethylcyclopentadienyl)(η 4 -tetraphenylcyclobutadiene)
钴(I)(阿尔图斯胺)。此例行高度非对映cyclopalladation,得到二- μ-
乙酸双- ([R )- [(η 5 - (小号p)-2-(α- Ñ,Ñ二甲基
氨基乙基)
环戊二烯基,1- Ç,Ñ)(η 4 -tetraphenylcyclobutadiene)
钴(I)]二
钯,和高度非对映
锂化,得到(- [R )- (η 5 - (小号p)-1-(α-