- Method for synthesizing chiral alpha-amino alcohol compound
-
The invention discloses a method for synthesizing a chiral alpha-amino alcohol compound. The method comprises the following steps: sequentially adding an iron catalyst, a ligand, ketone, an organic solvent and silane into a reaction system at 20-30 DEG C in a nitrogen atmosphere, then stirring the obtained mixture, and carrying out column chromatography separation on the obtained product to obtain a product, namely chiral alpha-amino alcohol. According to the invention, the most high-yield iron catalyst in earth crust is used, and cheap silane (PMHS, 500 g/298 yuan) is adopted as a reducing agent, so the asymmetric reduction reaction of alpha-amino ketone can be efficiently achieved under mild conditions so as to obtain the high-yield optically-active chiral alpha-amino alcohol compound; and moreover, through the creative labor of the inventor, reaction yield can reach 99%, and meanwhile, the content of the target product in the generated reaction product is 99%.
- -
-
Paragraph 0026; 0038-0041
(2021/07/28)
-
- Recyclable Cu(II)-macrocyclic salen complexes catalyzed nitroaldol reaction of aldehydes: A practical strategy in the preparation of (R)-phenylephrine
-
Chiral macrocyclic salen ligands 1′-3′ derived from 1R,2R-(-)-1,2-diaminocyclohexane, 1R,2R-(+)-1,2-diphenyl-1,2-diaminoethane and (R)-(+)-1,1′-binaphthyl-2,2′-diamine with trigol bis aldehyde were prepared and characterized by microanalysis, 1H NMR, UV/Vis. spectroscopy, optical rotation and mass spectroscopy. Highly enantioselective nitroaldol reaction of various aromatic and aliphatic aldehydes with nitromethane in presence of several bases were carried out in the presence of in situ generated Cu(I)/Cu(II) complexes with chiral macrocyclic salen ligands 1′-3′ at RT. Excellent yields (up to 92% with respect to the aldehyde) of β-nitroalcohols with high enantioselectivity (ee, ~95%) was achieved in case of 3-methoxy- and 4-nitrobenzaldehyde in ca. 30 h with the use of chiral macrocyclic salen ligands 3′ with CuCl2· 2H2O in presence of 2,6-lutidine as a base. Chiral macrocyclic salen catalyst 3 mediated nitroaldol process is recyclable (up to 8 cycles with no significant loss in its performance). This protocol is also used for the synthesis of enantiomerically pure (R)-phenylephrine (α1-adrenergic receptor agonist) via asymmetric nitroaldol reaction of 3-methoxybenzaldehyde in three steps.
- Kureshy, Rukhsana I.,Dangi, Balchand,Das, Anjan,Khan, Noor-Ul H.,Abdi, Sayed H.R.,Bajaj, Hari C.
-
-