Uses
3-Bromothioanisole is a useful reagent for the preparation of (Z)-1,2-diborylalkenes via sodium-metal-promoted reductive 1,2-syn-diboration of alkynes with reduction-resistant trimethoxyborane.
Synthesis
GENERAL METHOD: 3-bromophenylboronic acid (1.0 mmol), dimethyl disulfide (2.0 mmol), di-tert-butyl peroxide (DTBP, 3.0 mmol) and acetonitrile (CH3CN, 2.0 mL) were added sequentially to a sealed tube. The reaction mixture was stirred at 120 °C in air for 12 hours. After completion of the reaction, it was cooled to room temperature and the reaction mixture was diluted with deionized water (5 mL) and subsequently extracted with ethyl acetate (EtOAc, 4 × 10 mL). The organic phases were combined, washed with saturated saline (3 × 10 mL), dried over anhydrous magnesium sulfate (MgSO4), filtered and concentrated. The crude product was purified by silica gel column chromatography with ethyl acetate/hexane as eluent (v/v = 1:30 to 1:100). The resulting 3-bromothioanisole was characterized by spectroscopic analyses (NMR hydrogen spectroscopy, carbon spectroscopy, etc.) and compared with the data of known compounds (see Supporting Information for details).
References
[1] Synlett, 2016, vol. 27, # 15, p. 2269 - 2273
