1,2-Dibromoethane → [4-(Diphenylphosphanyl)butyl](oxo)diphenyl-lambda~5~-phosphane

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Reaction Steps

A mixture of palladium acetate (10 mg; 4.45×10-2 mmol), dppb (4.00 g; 9.4 mmol), 1,2-dibromoethane (3.6 g; 19.15 mmol), and dichloromethane (10 mL) was stirred for 30 minutes. To this suspension, aqueous NaOH (20% by weight; 10 mL) was added and the mixture was vigorously stirred at room temperature for 3 days. Dichloromethane (30 mL) was added, the organic phase was filtered through a silica plug which was then washed with 80 mL of CH2Cl2 /AcOEt (5:3 by volume). The combined organic solutions were evaporated to dryness. The solid residue was dissolved in boiling CH2Cl2 (ca. 30 mL) and the solution was treated with ether (100 mL; portionwise) and left at room temperature for 2 hours. Well-shaped, colorless crystals were separated, washed with ether, and dried under vacuum. The yield was 3.33 g (80%). 1H NMR (CDCl3, 20° C.), δ: 1.5 (m, 2H, CH2); 1.7 (m, 2H, CH2); 2.0 (m, 2H, CH2); 2.2 (m, 2H, CH2); 7.2-7.8 (m, 20H, Ph). 31P NMR (CDCl3, 20° C.), δ: -15.5 (s, 1P, PPh2); 32.2 (s, 1P, P(O)Ph2).

Provenance & Evidence