first example of metal-free B(C6F5)3-catalyzed asymmetric reduction amination of ketones with chiral α-methylbenzylamine (α-MBA) using ammonia borane as the reductant is reported. This one-pot method has a broad substrate scope and provides various chiralamines in 81–95% yield with 80–99% de. This protocol was further applied in the total synthesis of cinacalcet.
报道了使用氨硼烷作为还原剂,用手性α-甲基苄胺(α-MBA)进行的无金属的B(C 6 F 5)3催化的酮的不对称还原胺化的第一个实例。这种一锅法具有广泛的底物范围,并以81-95%的收率和80-99%的de提供了各种手性胺。该方案进一步应用于西那卡塞的全合成中。
A facile method for the asymmetric synthesis of enantiomerically pure 1-(2-fluorophenyl)-ethylamine [1]
作者:G. Bringmann、J.-P. Geisler
DOI:10.1016/s0022-1139(00)80363-2
日期:1990.7
A simple, two-step-procedure for the synthesis of optically active (S)-1-(2-fluorophenyl)- ethylamine (1) is described. Starting from commercially available 2-fluoro-acetophenone (2), imination with (S)-1-phenyl-ethylamine (3), followed by stereoselective hydrogenation over Raney-nickel gives the secondary amine 5a. Subsequent regioselective hydrogenolytic cleavage of homogenous 5a yields enantiomerically
Routes to enantioenriched amines are outlined that employ reductive amination and carbanion addition methods. The strategies require either one or two reaction steps from prochiral carbonyl compounds for the synthesis of the corresponding chiral primary amines.
Sequential Reductive Amination-Hydrogenolysis: A One-Pot Synthesis of Challenging Chiral Primary Amines
作者:Thomas C. Nugent、Daniela E. Negru、Mohamed El-Shazly、Dan Hu、Abdul Sadiq、Ahtaram Bibi、M. Naveed Umar
DOI:10.1002/adsc.201100250
日期:2011.8
Difficult-to-access chiralprimaryamines were formed in good to high yield and ee using a rare example of a one-potsynthesis from prochiral ketones (sequentialreductive amination-hydrogenloysis). As a highlight we also demonstrate a one-potreductive amination-hydrogenolysis-reductive amination (five reactions) of ortho-methoxyacetophenone resulting in the chiral diamine 1-(2-methoxyphenyl)ethy