Markedly improving asymmetric oxidation of 1-(4-methoxyphenyl) ethanol with Acetobacter sp. CCTCC M209061 cells by adding deep eutectic solvent in a two-phase system

Table 1 Effect of various hydrophobic solvents on the asymmetric oxidation of MOPE catalyzed by Acetobacter sp. CCTCC M209061 cells

Hydrophobic solvents	Log P	Initial rate (μmol/min)	Reaction time (h)	Conversion^a (%)	e.e. ^b (%)
Aqueous buffer	–	75.0	10.0	47.5	91.7
Ethyl acetate/buffer	0.7	7.2	26.0	24.1	31.7
Isopropyl ether/buffer	1.9	16.8	24.0	36.0	56.3
Cyclohexane/buffer	3.0	45.0	13.0	47.2	89.0
n-hexane/buffer	3.5	51.3	12.0	48.0	92.3
Isooctane/buffer	3.9	42.5	15.0	45.5	83.4
n-nonane/buffer	4.7	34.9	18.0	42.7	74.5
Dodecane/buffer	6.6	30.3	20.0	41.0	69.5
[C₄MIM][PF₆]/buffer	–	59.3	12.0	48.5	95.1
[C₅MIM] [PF₆]/buffer	–	50.1	12.5	46.3	87.3
[C₂MIM][Tf₂N]/buffer	–	42.6	13.0	41.6	72.4
[C₄MIM][Tf₂N]/buffer	–	36.1	14.0	35.5	56.0
[PP₁₄][Tf₂N]/buffer	–	25.9	15.0	30.1	44.6

Reaction conditions: 3.5 mL TEA-HCl buffer (100 mmol/L, pH 6.5); 0.3 g/mL immobilized cells; 122 mmol/L acetone; 1.5 mL organic solvent containing 5.04 mmol/L n-tetradecane (as internal standard) or 1.5 mL hydrophobic IL; 50 mM MOPE; 30 °C; 200 rpm
^aThe maximum conversion
^bThe residue substrate e.e.

ISSN: 1475-2859