Sodium borohydride → (4-Fluoro-2-vinylphenyl)methanol

To a mixture of 1-bromo-4-fluoro-2-vinylbenzene (0.32 g, 1.592 mmol) in tetrahydrofuran (5 mL) at −78° C. was added BuLi (0.764 mL, 1.910 mmol) dropwise. It was then stirred at this temperature for 1 h, then N,N-dimethylformamide (0.185 mL, 2.388 mmol) was added. The reaction mixture was stirred at −78° C. for 30 min, then warmed to rt and stirred at rt for 3 h. It was then quenched with NH4Cl, extracted with ether. The organic layer was dried over MgSO4, filtered and concentrated to obtain 4-fluoro-2-vinylbenzaldehyde (0.2 g) as an oil, which was used in the next step without purification. A mixture of 4-fluoro-2-vinylbenzaldehyde (200 mg, 1.332 mmol) and NaBH4 (50.4 mg, 1.332 mmol) in MeOH (2 mL) was stirred at rt for 1 h. It was then diluted with water, extracted with EtOAc. The organic layer was dried over MgSO4, filtered and concentrated. The residue was purified by biotage, eluting with 20% EtOac/hexane to obtain (4-fluoro-2-vinylphenyl)methanol (150 mg, 0.986 mmol, 74.0% yield) as an oil. 1H NMR (400 MHz, CDCl3) δ 7.35 (dd, J=8.3, 5.9 Hz, 1H), 7.25 (dd, J=10.0, 2.7 Hz, 1H), 7.09-7.02 (m, 1H), 7.02-6.95 (m, 1H), 5.73 (d, J=17.4 Hz, 1H), 5.44 (d, J=11.0 Hz, 1H), 4.75 (d, J=4.9 Hz, 2H).