Asymmetric hydroamination of acrylonitrile derivatives catalyzed by Ni(II)-complexes
作者:Luca Fadini、Antonio Togni
DOI:10.1016/j.tetasy.2008.11.010
日期:2008.11
Chiral ferrocenyl tridentate phosphine ligands were synthesized and used in asymmetric hydroamination reactionscatalyzed by Ni(II)-complexes. Compounds of the type [Ni(PPP)L]2+, where L is a chloride, solvent molecule or a coordinated substrate, were isolated. The efficiency of these complexes in asymmetric catalysis was high when aliphatic or aromatic amines were reacted with electron-poor olefins
Selective and Nonselective Aza-Michael Additions Catalyzed by a Chiral Zirconium Bis-Diketiminate Complex
作者:Ibrahim El-Zoghbi、Myriam Kebdani、Todd J. J. Whitehorne、Frank Schaper
DOI:10.1021/om400544z
日期:2013.12.9
and reduces the reaction order in amine to first order. Other activated alkenes such as methacrylonitrile, crotonitrile, methyl acrylate, and cyclohexenone can be employed, but no reactivity is observed toward styrene or vinyl ethers. Primaryamines, secondary amines, and anilines can be employed as nucleophiles with activities correlating with their nucleophilicity, but the catalyst is unstable in
Asymmetric syntheses of β-amino acids were achieved by the addition of chiral amines, R (+)- and S (-)-α-methylbenzylamines (1b and 1c), to crotonitrile, methyl crotonate (5a), l-menthyl crotonate (5b), ethyl cinnamate (5c), and methacrylonitrile, and by the addition of benzylamine (1a) to 5b, in the range of 2-19% optical purities. Among them, the configuration of the resulting β-amino acids was same as 1b and 1c used, in the reactions with crotonitrile and 5c, but was different in the cases of 5a and 5b and methacrylonitrile.
β-氨基酸的不对称合成通过手性胺 R (+)-和 S (-)-α-甲基苄胺 (1b 和 1c) 与克罗顿腈、甲基克罗顿酸酯 (5a)、L-薄荷基克罗顿酸酯 (5b)、乙基肉桂酸酯 (5c) 和甲基丙烯腈的加成实现,光学纯度范围为2%到19%。其中,所得到的β-氨基酸的构型与用于与克罗顿腈和5c反应的1b和1c相同,但在5a、5b和甲基丙烯腈的情况下则不同。