Lou, Yan-Peng; Zheng, Chang-Wu; Pan, Ren-Ming; Jin, Qiao-Wen; Zhao, Gang; Li, Zhong published an article on February 6 ,2015. The article was titled 《Enantioselective Direct Mannich Reactions of Cyclic β-Ketoesters Catalyzed by Chiral Phosphine via a Novel Dual-Reagent Catalysis》, and you may find the article in Organic Letters.Formula: C18H24NP The information in the text is summarized as follows:
A combination of an amino acid derived chiral phosphine catalyst and Me acrylate efficiently catalyzed the direct Mannich reaction of cyclic β-ketoesters and N-Boc-aldimines. The dual-reagent catalysis was presumed to function through the formation of a zwitterion, which catalyzed the reaction with excellent stereocontrol via a hydrogen-bonding assisted chiral ion-pair pathway. After reading the article, we found that the author used (S)-1-(Diphenylphosphino)-3,3-dimethylbutan-2-amine(cas: 286454-86-2Formula: C18H24NP)
(S)-1-(Diphenylphosphino)-3,3-dimethylbutan-2-amine(cas:286454-86-2) is one of aminophosphine type ligands. An increased interest in aminophosphine type ligands used for asymmetric synthesis has been witnessed.Formula: C18H24NP This growth in popularity of aminophosphine ligands in asymmetric synthesis is in part due to the growing number of convenient synthetic pathways leading to useful ligand sets.
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis