Potassium 4-butylphenyltrifluoroborate synthesis

Yield:1412414-09-5 85%

Reaction Conditions:

Stage #1: diisopropylamine borane;p-bromobutylbenzenewith magnesium in tetrahydrofuran at 70;
Stage #2: with methanol in tetrahydrofuran at 0; for 1 h;
Stage #3: potassium hydrogenfluoride in methanol;water at 20; for 1 h;

Steps:

Addition under Barbier conditions (procedure A)

General procedure: A solution in THF (4 mL) of DIPAB (863 mg, 7.5 mmol), Mg (182 mg, 7.5 mmol) and arylbromide (5 mmol) was stirred at 70 °C until no starting arylbromide remains (TLC). The reaction mixture was cooled down to 0 °C and quenched slowly with 7 mL of MeOH. After 1h, volatile were removed under reduced pressure and the resulting solid was dissolved in MeOH. An aqueous solution of KHF₂ (4.5 eq, 10 mL) was added at room temperature. After 1h at room temperature, volatiles were removed under reduced pressure; the solid was extracted with anhydrous acetone and the resulting powder was recrystallized from acetone/Et₂O or acetone/pentane.

References:

Marciasini, Ludovic D.;Richard, Jimmy;Cacciuttolo, Bastien;Sartori, Guillaume;Birepinte, Melodie;Chabaud, Laurent;Pinet, Sandra;Pucheault, Mathieu [Tetrahedron,2019,vol. 75,# 2,p. 164 - 171]