General procedure for the synthesis of 1-cyclopropylnaphthalene from 1-bromonaphthalene and cyclopropylmagnesium bromide: Cyclopropylmagnesium bromide (150 mL, 0.5 M in tetrahydrofuran) was added slowly and dropwise to a solution of tetrahydrofuran (10 mL) containing 1-bromonaphthalene (10 g, 50 mmol) and [1,3-bis(diphenylphosphino)propane]nickel(II) dichloride at 0 °C. The reaction mixture was stirred at room temperature for 16 hours. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure. The residue was extracted by adding ethyl acetate and aqueous ammonium chloride solution to the residue. The organic layer was separated, dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure. Finally, the residue was purified by silica gel column chromatography to afford 1-cyclopropylnaphthalene (6.4 g, 76% yield).
