Chiral cyclic trans-β-acetamido alcohol and its preparation method
A technology of acetamido alcohol and acetamido ketone, which is applied in the field of preparation of chiral cyclic trans-β-acetamido alcohol, to achieve the effects of high enantioselectivity, reduction of synthesis cost and improvement of synthesis efficiency
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
preparation example Construction
[0027] The preparation method of the invention is carried out under the catalysis of the bisphosphine-rhodium complex. In the present invention, the bisphosphine-rhodium complex can be represented by [Rh(L)(L')]X. L is selected from the following (R, R)-Me-Duphos, (R, S)-BenzP*, (R, R)-QuinoxP*, (R, R)-Miniphos, or (S)-TCFP, ( R)-3H-QuinoxP* and any chiral bisphosphine ligand in their enantiomers, namely (R, S)-Me-Duphos, (R, S)-BenzP*, (R, S)-QuinoxP*, (R, S)-Miniphos, or (R)-TCFP, (S)-3H-QuinoxP*; as L' can be 1,5-cyclooctadiene or 2,5-norbornene Diene; as X can be cited SbF 6 - or BF 4 - .
[0028]
[0029] In the preparation method of the present invention, the hydrogen pressure is not particularly limited, as long as the asymmetric catalytic hydrogenation reaction of the present invention can be carried out. However, from the viewpoint of reaction yield and reaction efficiency, the hydrogen pressure in the hydrogen atmosphere is set to 1-100 bar, preferably 1-50...
Embodiment 1
[0050] The preparation example of
[0051] In a 500mL two-necked bottle, add anhydrous aluminum trichloride (AlCl 3)36mmol, 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 12 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.
[0052] The measurement ...
Embodiment 2
[0055] The preparation example of
[0056] Add 1.5mg of [Rh((R,R)-Me-Duphos)(nbd)]SbF to a 50mL reaction tube 6 Catalyst, the substrate 1a of 38mg [substrate: catalyst=100: 1 (molar ratio)], reaction test tube is placed in hydrogenation kettle, vacuumizes and changes hydrogen three times, adds the ethanol of 2mL degassing under the protection of hydrogen, and finally 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%.
[0057] The measurement data of 2a are as follows.
[0058] 1 H NMR (400MHz, CD 3 OD): δ8.44(br s, 1H), 7.44-7.13(m, 4H), 4.99(d, J=6.4Hz, 1H), 4.32(q, J=6.8Hz, 1H), 3.31(dd, J=15.2, 8.0Hz, 1H), 2.70(dd, J=15.6, 8.0Hz, 1H), 2.00(s, 3H);
[0059] 13 C NMR (100MHz, CD 3 OD): δ172.4, 142.6, 139.3, 128.0, 126.7, 124.3, 123.8, 79.4, 59.7, 35.3, 21.2;
[0060] IR (KBr): v 3315, 16...
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More