3-Bromopyridine → 3-Cyclopentylpyridine

Participants

Reaction Conditions

Reaction Steps

3-Bromopyridine (3.9 ml, 40 mmol) and [1,2-bis(diphenylphosphino)ethane]dichloronickel(II) (160 mg, 0.3 mmol) were dissolved in dry tetrahydrofuran (25 ml) and cooled to −5° C. Cyclopentylmagnesium chloride (2.0M in diethyl ether, 20 ml, 40 mmol) was added dropwise over 5–10 minutes and the reaction was allowed to warm slowly to room temperature. Further cyclopentylmagnesium chloride (2.0M in diethyl ether, 5 ml, 10 mmol) was added. The reaction was quenched by the addition of saturated aqueous ammonium chloride solution. The mixture was partitioned between water and ethyl acetate. The organic layer was dried (MgSO4) and concentrated in vacuo. The residue was purified by flash column chromatography on silica, eluting with 20–35% ethyl acetate/i-hexane, to give the title compound (1.74 g, 30%).

Provenance & Evidence