Acyclic chiral amines and amino acids as inexpensive and readily tunable catalysts for the direct asymmetric three-component Mannich reaction.
The direct three-component asymmetric Mannich reaction catalyzed by acyclic chiral amines or amino acids is presented. Simple acyclic chiral amines and amino acids--such as alanine-tetrazole (9), alanine, valine, and serine-catalyzed the three-component asymmetric Mannich reactions between unmodified ketones, p-anisidine, and aldehydes with high chemo- and stereoselectivity, furnishing the corresponding Mannich bases with up to >99 % ee. This study demonstrates that the whole range of amino acids in nature, as well as nonproteogenic amino acid derivatives, can be considered in the design and tuning of novel, inexpensive organocatalysts for the direct asymmetric Mannich reaction.
Ibrahem
Ismail
I
Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 106 91 Stockholm, Sweden.
Zou
Weibiao
W
Engqvist
Magnus
M
Xu
Yongmei
Y
Córdova
Armando
A
D000588:Amines / Q000737:chemistry*; D000596:Amino Acids / Q000737:chemistry*; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013237:Stereoisomerism
D000588:Amines; D000596:Amino Acids