New chiral ferrocenyl P,S-ligands for highly diastereo-/enantioselective catalytic [3 + 2] cycloaddition of azomethine ylides with cyclic and acyclic enones was written by Zhang, Cheng;Yu, Sai-Bo;Hu, Xiang-Ping;Wang, Dao-Yong;Zheng, Zhuo. And the article was included in Organic Letters in 2010.Name: (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine This article mentions the following:
A new family of chiral ferrocenyl P,S-ligands I (R = Me, i-Pr, Ph, 4-ClC6H4, 4-MeC6H4, PhCH2) has been developed and successfully applied in a highly endo-selective catalytic asym. cycloaddition of azomethine ylides with various enones, including cyclic and acyclic α-enones. For cyclic α-enones, [Cu(CH3CN)4]ClO4/(Rc,SFc)-I (R = i-Pr) complex catalyzed the cycloaddition to give the sole endo-cycloadducts in perfect enantioselectivities (normally 99% ee), while AgOAc/(Rc,SFc)-I (R = i-Pr) catalytic system exhibited good endo/exo selectivities (endo/exo = 91/9 to 96/4) and high enantiocontrol (up to 98% ee) for acyclic α-enones. In the experiment, the researchers used many compounds, for example, (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2Name: (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine).
(R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2) belongs to chiral phosphine ligands. At present, the synthesis of new chiral phosphines designed specifically for nucleophilic organocatalysis remains a significant challenge. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Name: (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis