Cyclic alpha-dehydroamino ketones, chiral cyclic alpha-amino ketone and preparation method thereof
A technology for dehydroaminoketones and aminoketones, applied in the field of preparation of chiral cyclic α-aminoketones, which can solve problems such as poor atom economy, difficulty in obtaining high enantioselective products, instability, etc. , achieve high enantiomer selectivity, realize industrial synthesis, and reduce synthesis cost
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[0026] In the preparation method of the chiral cyclic α-amino ketone of the present invention, R in the general formula (1) and general formula (2) does not change before and after the reaction.
[0027] In general formula (1) and general formula (2), R is selected from hydrogen atom, C1-C6 alkyl, phenyl, substituted phenyl, C1-C7 acyl, C1-C7 alkoxyacyl, hydroxyl, C1- C7 alkoxy, C1-C7 acyloxy, amino, mono(C1-C7 alkyl) amino, di(C1-C7 alkyl) amino, C1-C7 amido, trimethylsilyl, dihydroxy Any one or two or more of boron group, diphenylphosphinooxy group, phenylmercapto group, fluorine atom, chlorine atom, bromine atom and iodine atom. Among them, examples of the C1-C6 alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, and hexyl. etc.; as substituted phenyl groups, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxy phenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, 4-ethoxyphenyl, 2...
Embodiment 1
[0053] The preparation example of
[0054] In a 500mL two-necked bottle, add anhydrous aluminum trichloride (AlCl 3 ) 12mmol, then add 60mml tetrachlorethylene solvent, the mixture is stirred at room temperature for 1 hour, then under stirring, slowly add 4-phenylmethylene-2-methyl-5(4H)-oxazolone 60 mL of 36 mmol perchlorethylene solution, after adding all the perchlorethylene solution, heat the reaction solution, stir and react at 100°C for 1 hour, then return to normal temperature and stir for 2 hours. After the reaction, add 120mL of 1mol / L dilute hydrochloric acid solution, stir for 10 minutes, extract the organic layer, wash the water phase twice with dichloromethane, combine the organic phases, and remove the solvent by rotary evaporation. The residue can be separated by column chromatography. The pure product 1a was obtained. The product 1a was directly used for hydrogenation after recrystallization from dichloromethane and petroleum ether.
[0055] The measuremen...
Embodiment 2
[0059] The preparation example of
[0060] Add 2.8mg of [Rh((R)-BINAP)(nbd)]SbF to a 50mL reaction tube 6 Catalyst, the substrate 1a [substrate of 56mg: catalyst=100:1 (molar ratio)], reaction test tube is placed in hydrogenation kettle, vacuumizes and changes hydrogen three times, adds the methyl alcohol of 2mL degassing under the protection of hydrogen, finally will The hydrogen pressure was adjusted to 100 bar, and the reaction was stopped under vigorous stirring at 50° C. for 1 hour. The solvent was concentrated and evaporated to dryness to obtain a white solid product 2a with a yield of 99%.
[0061] The measurement data of 2a are as follows.
[0062] 1 H NMR (400MHz, CDCl 3 ):δ2.08(s,3H),2.96(dd,J=5.6Hz,16.8Hz,1H),3.75(dd,J=8.2Hz,16.4Hz,1H),4.52-4.58(m,1H), 6.39(br s, 1H), 7.39(t, J=7.6Hz, 1H), 7.45(d, J=7.6Hz, 1H), 7.63(t, J=7.6Hz, 1H), 7.75(d, J= 7.6Hz,1H);
[0063] 13 C NMR (100MHz, CDCl 3 ): δ23.2, 35.1, 56.8, 124.4, 126.9, 128.1, 134.9, 135.9, 151.7, 171.0...
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