反应详情

A mixture of palladium acetate (5 mg; 2.2×10-2 mmol), dppm (2.00 g; 5.21 mmol), 1,2-dibromoethane (2.0 g; 10.64 mmol), and dichloromethane (10 mL) was stirred for 20 minutes. To this solution, aqueous NaOH (20% by weight; 6 mL) containing NaI (40 mg; 0.27 mmol) was added and the mixture was vigorously stirred under reflux for 4 hours. The organic phase was filtered through a silica plug which was then washed with CH2Cl2 /AcOEt (3:1 by volume). The combined organic solutions were evaporated to dryness. The solid residue was dissolved in the minimum amount of boiling CH2Cl2, the warm solution was treated with ether (100 mL; portionwise) and left at room temperature for 2 hours. Slightly yellowish fluffy needles of spectroscopically and TLC pure dppmO were separated, washed with ether, and dried under vacuum. The yield was 1.53 g (74%). 1H NMR (CDCl3, 20° C.), δ: 3.1 (d, 2H, J=12.7 Hz, CH2); 7.1-7.9 (m, 20H, Ph). 31P NMR (CDCl3, 20° C.), δ: -26.5 (d, 1P, JP-P =50.5 Hz, PPh2); 29.8 (d, 1P, JP-P =50.5 Hz, P(O)Ph2).

1. additionwas added
2. stirringthe mixture was vigorously stirred
3. temperatureunder reflux for 4 hours
4. filtrationThe organic phase was filtered through a silica plug which
5. washwas then washed with CH2Cl2 /AcOEt (3:1 by volume)
6. customThe combined organic solutions were evaporated to dryness
7. dissolutionThe solid residue was dissolved in the minimum amount of boiling CH2Cl2
8. additionthe warm solution was treated with ether (100 mL
9. waitportionwise) and left at room temperature for 2 hours
10. customSlightly yellowish fluffy needles of spectroscopically and TLC pure dppmO were separated
11. washwashed with ether
12. customdried under vacuum