反应详情

温度

200 °C

A flask was charged with 1.05 g of 2,2,6,6-tetramethyl-1-(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphinan-4-one (2.33 mmol, 1.0 equiv), the atmosphere was sparged with argon and 12 mL of argon-sparged diethylene glycol was added. The flask was mounted with a Dean-Stark trap and condenser to collect distillate. The mixture was charged with 1.05 mL of hydrazine hydrate (55 wt % hydrazine, 11.7 mmol, 5 equiv) and 0.77 g of potassium hydroxide (88 wt %, 12.1 mmol, 5 equiv) and the mixture was immersed in an oil bath at 115° C. under an argon atmosphere. The temperature of the bath was gradually increased to 200° C. over two hours and kept at that temperature for 5 h. The reaction mixture was cooled to room temperature under argon gas. The reaction mixture was partitioned between heptane and water. The organic solution was washed once with 0.1 M aqueous hydrochloric acid, once with 10 wt % aqueous sodium carbonate and once with water. The organic solution was concentrated in vacuo with gentle heating and the residue dried in vacuo to give 0.99 g of 2,2,6,6-tetramethyl-1-(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphinane (97 area % by HPLC, 94% yield) as a white solid. 1H NMR (C6D6, 500 MHz), δ=0.93 (d, 6H, J=10 Hz), 1.11 (d, 6H, J=7 Hz), 1.13 (d, 6H, J=19 Hz), 1.23 (d, 6H, J=7 Hz), 1.31-1.26 (m, 2H), 1.42 (d, 6H, J=7 Hz), 1.57-1.50 (m, 1H), 1.65-1.57 (m, 1H), 1.88-1.83 (m, 2H), 2.79 (sept, 2H, J=7 Hz), 2.84 (sept, 1H, J=7 Hz), 7.12-7.11 (m, 2H), 7.22 (s, 2H), 7.27-7.24 (m, 1H), 7.98-7.93 (m, 1H); 31P NMR (C6D6, 202 MHz), δ ppm −0.4 (br singlet).

1. customthe atmosphere was sparged with argon and 12 mL of argon-
2. customsparged diethylene glycol
3. additionwas added
4. distillationto collect distillate
5. customthe mixture was immersed in an oil bath at 115° C. under an argon atmosphere
6. temperatureThe reaction mixture was cooled to room temperature under argon gas
7. customThe reaction mixture was partitioned between heptane and water
8. washThe organic solution was washed once with 0.1 M aqueous hydrochloric acid, once with 10 wt % aqueous sodium carbonate and once with water
9. concentrationThe organic solution was concentrated in vacuo
10. temperaturewith gentle heating
11. customthe residue dried in vacuo