Table 4 Literature survey of studies on the reductive enzymatic kinetic resolution of rac-2-phenylpropanal

Horse liver ADH (Zn-containing ADH)

1

Free enzyme,

coupled substrate 1,4-butanediol

5 mM

Buffer pH 7.5, 1% v/v CH₃CN,

(2.5 mM 1,4-butanediol)

5 mM

(98%)

95% ee S

Probing the enzyme's coenzyme recycling ability using the oxidation of 1,4-butanediol into the corresponding lactone

14

2

Free enzyme,

coupled substrate ethanol

0.5 mM

Buffer pH 7.5,

(0.5 M ethanol)

0.38 mM

(75%)

98% ee S

Investigation of DKR, including substrate racemization velocity

10,15

3

Free enzyme, phenylpropanal oxidation for NADH-recycling

75 mM

Buffer pH 7.5; 4% v/v MTBE

28 mM

(37%)

96% ee S

Investigation of a biocatalytic asymmetric disproportionation (biocatalytic Cannizzaro reaction)

12

4

Free enzyme, coupled substrate ethanol

165 mM

Buffer, 63% v/v isopropyl ether,

(0.6 M ethanol)

82 mM

(50%)

96% ee S

Probing the enzyme's enantioselectivity and coenzyme recycling ability

16

5

Free enzyme,

coupled substrate ethanol

30 mM

Buffer pH 8,

(5% v/v ethanol)

28 mM

(93%)

93% ee S

One-pot, two-step reaction: oxidation of rac-2-phenyl-1-propanol into rac-2-phenylpropanal followed by a dynamic enantioselective bioreduction

1

6

Immobilized enzyme,

coupled substrate ethanol

5 mM

Buffer pH 7.5, 50% v/v hexane,

(0.5 M ethanol)

4.2 mM

(84%)

 > 98% ee S

Characterization of the immobilized catalyst

17

7

Immobilized enzyme,

coupled substrate ethanol

300 mM

Isopropyl ether (saturated with buffer), 0.5% buffer pH 7.0,

(1 M ethanol)

46 mM

(15%)

95% ee S

Probing the enzyme's substrate scope and enantioselectivity in organic solvents

11

Thermostable ADHs (enzyme superfamily)

8

Free Thermoanaerobacter brockii LG296 ADH mutant (Zn-containing ADH),

coupled substrate isopropanol

30 mM

Buffer pH 7.4,

(20% v/v isopropanol)

23 mM

(75%)

95% ee S

Development of enantioselective mutants

8

9

Free Thermoanaerobacter brockii LG277 ADH mutant (Zn-containing ADH),

coupled substrate isopropanol

10 mM

Buffer pH 7.4,

(20% v/v isopropanol)

7.5 mM

(75%)

92% ee R

Development of enantioselective mutants

8

10

Free Sulfolobus solfataricus ADH-10 (Zn-containing ADH), coupled substrate ethanol

5 mM

Buffer pH 9,

(5% ethanol)

3.7 mM

(74%)

98% ee S

Probing the enzyme's substrate scope and enantioselectivity

9

11

Immobilized Thermus thermophilus ADH (short-chain dehydrogenases/reductase),

coupled enzyme yeast formate dehydrogenase

1 mM

Buffer pH 7, 5% v/v CH₃CN

(0.1 M formic acid)

1 mM

(100%)

71% ee R

Characterization of the immobilized catalyst

13

Other ADHs (enzyme superfamily)

12

Free E. coli ADH (Zn-containing ADH)

30 mM

Buffer pH 8,

(5% v/v ethanol)

29 mM

(97%)

94% ee S

One-pot, two-step reaction: oxidation of rac-2-phenyl-1-propanol into rac-2-phenylpropanal followed by a dynamic enantioselective bioreduction

1

Origin of enzyme not stated

13

Free Evo-1.1.200 from Evocatal

coupled substrate ethanol

30 mM

Buffer pH 9,

(5% v/v isopropanol)

29 mM

(95%)

89% ee R

One-pot, two-step reaction: oxidation of rac-2-phenyl-1-propanol into rac-2-phenylpropanal followed by a dynamic enantioselective bioreduction

1

Whole-cell catalysts

14

E. coli JM109, NAD(P)H-recycling by native microbial metabolism

22 mM

M9 medium, 30% v/v organic phase (9:1 isopropyl ether: isooctane)

4.4 mM

(20%)

 ~ 50% ee (? unknown)

Probing the host background activity

30

15

CtXR D51A mutant (aldo–keto reductase)

coupled enzyme yeast formate dehydrogenase

1000 mM

Buffer pH 7.5,

(1.05 M formic acid)

843 mM

(98.8%, but product and substrate loss)

93.1% ee S

Process optimization for imroved enantiopurity and yield

This work