Phosphoric Acid → [3-({[(1,1-Dimethylethyl)(dimethyl)silyl]oxy}methyl)phenyl]boronic acid

Participants

Reaction Conditions

Reaction Steps

A solution of {[(3-bromophenyl)methyl]oxy}(dimethyl)silane-2,2-dimethylpropane (1:1) (100.0 g, 331.9 mmol) in THF (500 mL) was cooled to −78° C., and then n-BuLi (132.7 mL, 331.9 mmol) was added dropwise. The mixture was stirred for 1 h at −78° C. Then B(OBu)3 (107.5 mL, 398.2 mmol) was added in one portion. The reaction mixture was warmed to room temperature, and stirred over night. After cooling to 0° C., 5% H3PO4 was added to pH=4-5 and the mixture stirred 0.5 h and then filtered. After removing THF, the residue was extracted with Et2O (200 mL×2), and the organic layer was dried over Na2SO4. After removing the solvent, the residue was added to water, and a white solid precipitated which was dried in vacuo to give 65.7 g of [3-({[(1,1-dimethylethyl)-(dimethyl)silyl]oxy}methyl)phenyl]boronic acid (yield: 74.5%). 1H NMR (400 MHz, CDCl3) δ 0.14 (s, 6H), 0.98 (s 9H), 4.88 (s, 2H), 7.49-7.59 (m, 2H), 8.14 (d, J=7.6 Hz, 1H), 8.19 (s, 1H).

Provenance & Evidence