Acetophenone → 1-Phenylethanol, (R)-

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Reaction Steps

The polymer of Example 1 (32 mg, 0.055 mmol based on the biphenyl subunit) and diethylzinc (0.01 mL, 0.1 mmol) were added to a Schlenk flask containing 10 mL of toluene (dried with Na and degassed with N2), under N2 and at room temperature, to form the organozinc species. The resulting mixture was stirred at r.t. for 20 minutes. Acetophenone (0.12 mL, 1 mmol) was then added. The resulting mixture was cooled to -30° C. and 1.5 mL of catecholborane (1.5 mmol, 1M in THF) was added. Stirring was continued at this temperature for 38 h. The reaction was then quenched with 1N HCl and the aqueous layer was extracted with ether. The combined organic extracts were washed with brine until pH=7 and then dried over anhydrous Na2SO4. Concentration of the organic layer with a rotary evaporator gave a yellow oil, which upon addition of methanol, precipitated the polymer. The filtrate was concentrated and purified by column chromatography on silica gel with EtOAc/hexanes (1:5) to give (R)-1-phenylethanol as a colorless liquid (98 mg, 81%). GC analysis on a β-Dex capillary column (Supelco Company), with helium as the carrier gas, a flow rate of 1 mL/min, and an increase in oven temperature from 100° C. at a rate of 1° C./min, showed an ee of 67.0%.

Provenance & Evidence