A chiral chroman-4-one compound, its preparation method and application
A technology for chroman and ketone compounds, which is applied in the field of chiral compound synthesis, can solve problems such as unreported synthesis, and achieve the effects of less photocatalyst consumption, less metal participation and mild reaction conditions
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Embodiment 1
[0033] ( R )-2-(2-(2′-pyridine) ethyl) chroman-4-ketone III-1 The specific preparation steps are as follows:
[0034]
[0035] Preparation procedure: Take a dry 25 mL schlenk tube and add 24.3 mg (0.15 mmol) of 4H -Benzothiopyran-4-one I-1, 10.5 mg (0.1 mmol) vinylpyridine II-1, DPZ (0.7 mg, 0.002 mmol), chiral phosphoric acid catalyst BA (13.3 mg, 0.02 mmol), Hans Esters HE 55.6 mg (0.18 mmol), then add 1 mL of dichloromethane, cover the bottle cap, degas with a vacuum pump 2-3 times at no higher than -78°C, 5-10 min each time, and inject Protected by argon, then placed at -25°C, after standing still for half an hour, irradiated with a 3 W blue light with a wavelength of 410-510 nm at a distance of about 3 cm from the schlenk tube, and reacted for 60 hours. After the reaction, the column layer Analysis and separation (petroleum ether / ethyl acetate = 10~3:1, volume ratio), concentration by rotary evaporation, and vacuum drying (drying at 25°C for 1 hour) yielded 23.4 mg of...
Embodiment 2
[0042] ( R )-2-(2-(2´-pyridine) ethyl)-6-fluorochroman-4-one III-2 The specific preparation steps are as follows:
[0043]
[0044] In this embodiment, the 4 in embodiment 1 H -benzothiopyran-4-one I-1 is replaced with 6-fluorobenzothiopyran-4-one I-2, and other steps are the same as in Example 1 to obtain 20.7 mg yellow oil ( R )-2-(2-(2´-pyridine) ethyl)-6-fluorochroman-4-one III-2, yield 72%, enantiomeric excess 94%. NMR and mass spectrometry data are: 1 H NMR (300 MHz, CDCl 3 ) δ 8.51 (d, J = 4.3 Hz, 1H), 8.02 (d, J = 2.0 Hz, 1H), 7.59 (t, J = 7.6Hz, 1H), 7.33 (dd, J = 8.4, 2.1 Hz, 1H), 7.21 (d, J = 8.5 Hz, 1H), 7.13 (dd, J = 11.9, 7.5 Hz, 2H), 3.50 (dd, J = 10.6, 6.5 Hz, 1H), 3.04 (m, 2H), 2.87(m, 2H), 2.15 (m, 2H); 13 C NMR (75 MHz, CDCl 3 ) δ 193.24 (s, 1H), 159.96 (s,1H), 149.39 (s, 2H), 139.51 (s, 1H), 136.56 (s, 2H), 133.42 (s, 3H), δ 131.3(d, J = 34.1 Hz), 128.9 (d, J = 48.9 Hz), 123.0, 121.5, 45.7, 41.0, 34.9,33.7; HRMS (ESI) m / z 310.0672 (M+Na + ...
Embodiment 3
[0046] ( R )-2-(2-(2'-pyridine) ethyl)-8-bromochroman-4-one III-3 The specific preparation steps are as follows:
[0047]
[0048] In this embodiment, the 4 in embodiment 1 H -Bromothiopyran-4-ketone I-1 is replaced with 8-bromobenzothiopyran-4-ketone I-3, and other steps are the same as in Example 1 to obtain 18.0 mg yellow oil ( R )-2-(2-(2´-pyridine)ethyl)-8-bromochroman-4-one III-3, yield 52%, enantiomeric excess 98%. NMR and mass spectrometry data are: 1 H NMR (300 MHz, CDCl 3 ) δ 8.52 (d, J = 4.3 Hz, 1H), 8.05 (d, J = 7.9 Hz, 1H), 7.62 (m, 2H),7.14 (m, 2H), 7.04 (t, J = 7.8 Hz, 1H), 3.50 (dt, J = 14.0, 5.2 Hz, 1H), 2.93(m, 4H), 2.21 (dd, J = 14.8, 7.0 Hz, 2H); 13 C NMR (75 MHz, CDCl 3 ) δ 193.8,160.0, 149.4, 142.5, 137.3, 136.6, 132.4, 127.9, 125.2, 123.1, 121.6, 44.7,40.3, 34.8, 33.8; HRMS (ESI) m / z 348.0056 (M+H + ), calc. for C 16 h 15 NOSBr348.0052.
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