2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → Tert-butyl(3,5-difluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenoxy)dimethylsilane

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl(3,5-difluorophenoxy)dimethylsilane (1.0 eq) in dry THF (0.2 M) under an atmosphere of N2 at −78° C. was added n-butyllithium (1 eq, 1.6 M in hexanes) slowly keeping the internal temperature below −65° C. The reaction was stirred for 1 hr at −78° C., followed by the addition of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.1 eq). The reaction was allowed to warm to room temperature. Upon completion, the reaction was quenched with NaHCO3 (sat.) and extracted with EtOAc. The organics were washed with brine, dried over Na2SO4, filtered and concentrated to yield tert-butyl(3,5-difluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenoxy)dimethylsilane in 91% yield. 1H NMR (400 MHz, <cdcl3>) δ ppm 0.21 (s, 6H) 0.97 (s, 9H) 1.37 (s, 12H) 6.33 (d, J=9.39 Hz, 2H).

Provenance & Evidence