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

HRID 705189Notes

Reaction equation

[C:1]([Si:5]([O:8][C:9]1[CH:14]=[C:13]([F:15])[CH:12]=[C:11]([F:16])[CH:10]=1)([CH3:7])[CH3:6])([CH3:4])([CH3:3])[CH3:2].C([Li])CCC.C(O[B:26]1[O:30][C:29]([CH3:32])([CH3:31])[C:28]([CH3:34])([CH3:33])[O:27]1)(C)C>C1COCC1>[C:1]([Si:5]([O:8][C:9]1[CH:10]=[C:11]([F:16])[C:12]([B:26]2[O:30][C:29]([CH3:32])([CH3:31])[C:28]([CH3:34])([CH3:33])[O:27]2)=[C:13]([F:15])[CH:14]=1)([CH3:7])[CH3:6])([CH3:4])([CH3:2])[CH3:3]

Participants

Conditions

Temperature: -78 °C

Procedure

To a solution of tert-butyl(3,5-difluorophenoxy)dimethylsilane (1.0 eq) in dry THF (0.2M) under an atmosphere of N2 at −78° C. was added n-butyllithium (1 eq, 1.6M 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, 6 H) 0.97 (s, 9 H) 1.37 (s, 12 H) 6.33 (d, J=9.39 Hz, 2 H).

Workup

customthe internal temperature below −65° C
temperatureto warm to room temperature
customUpon completion, the reaction was quenched with NaHCO3 (sat)
extractionextracted with EtOAc
washThe organics were washed with brine
dry with materialdried over Na2SO4
filtrationfiltered
concentrationconcentrated

Sources & evidence

ORD record: ord-ee7819d53acf4fcf952d130055c3c353
Source dataset: uspto-grants-2015_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09173883B2

Reaction notes

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