Biocatalysis: Enzymatic Synthesis for Industrial Applications

Abstract

Biocatalysis has found numerous applications in various fields as an alternative to chemical catalysis. The use of enzymes in organic synthesis, especially to make chiral compounds for pharmaceuticals as well for the flavors and fragrance industry, are the most prominent examples. In addition, biocatalysts are used on a large scale to make specialty and even bulk chemicals. This review intends to give illustrative examples in this field with a special focus on scalable chemical production using enzymes. It also discusses the opportunities and limitations of enzymatic syntheses using distinct examples and provides an outlook on emerging enzyme classes.

Keywords: biocatalysis; enzyme catalysis; industrial catalysis; organic synthesis; stereoselectivity.

Scheme 1

Routes to key precursor (S)‐5 for the anti‐depressant Duloxetine using KREDs.[ ^18a , ^19a , ²⁰ ].

Scheme 2

Synthesis of the alcohol intermediate 10 of LNP023 by a KRED. ^[28]

Scheme 3

A route to the chiral intermediate 13 of a gamma‐secretase inhibitor using a KRED and a transaminase. ^[29]

Scheme 4

An improved KRED process ^[30] for the synthesis of t‐butyl 6‐cyano‐(3R,5R)‐dihydroxyhexanoate 17 for the production of Atorvastatin 18.

Scheme 5

KRED‐catalyzed desymmetrization of ethyl secodione 19 for the synthesis of intermediates for steroidal drugs. ^[33]

Scheme 6

Selective mono‐acylation of diol 21 by lipase QL. ^[26]

Scheme 7

Hydroxylation of α‐isophorone 23 or diclofenac 25 by a P450‐monooxygenase from Bacillus megaterium expressed in E. coli. ^[25a]

Scheme 8

Transaminase‐catalyzed reductive amination exemplified for (S)‐Moipa 28.

Scheme 9

(S)‐Dimethenamide 29 (BASF) and (S)‐Metolachlor 30 (Syngenta).

Scheme 10

Lipase‐catalyzed kinetic resolution of racemic benzylamines exemplified for 1‐phenylethylamine 31. ^[55]

Scheme 11

Asymmetric synthesis of Sitagliptin 34 using an engineered transaminase (ATA). ^[59]

Scheme 12

Transaminase‐catalyzed asymmetric synthesis of an intermediate of a blockbuster for cardiovascular treatment. ^[63a]

Scheme 13

IRED‐mediated imine reduction for the synthesis of Sertraline 39. ^[78]

Scheme 14

Enzymatic reductive amination for the synthesis of the key intermediate 42 of the LSD1 inhibitor GSK2879552. ^[69]

Scheme 15

A combination of an enzymatic reaction catalyzed by PAL with copper‐catalyzed ring closure affords a key intermediate for angiotensin 1‐converting enzyme inhibitors. ^[94]

Scheme 16

PAL‐mediated synthesis of the key intermediate 47 for the production of EMA401. ^[95]

Scheme 17

Oxidation of trans‐2‐hexen‐1‐ol 49 to trans‐2‐hexen‐1‐al 50 by an aryl alcohol oxidase. ^[98]

Scheme 18

Oxidation of hydroxymethylfurfural to diformylfuran by galactose oxidase. ^[100]

Scheme 19

Cascade conversion of ferulic acid 53 into vanillin 55 with thermophilic enzymes. ^[102]

Scheme 20

Oxidation of galactitol 56 to d‐tagatose 57 by a polyol dehydrogenase. ^[105]

Scheme 21

Conversion of formaldehyde and dihydroxyacetone to l‐erythrulose 60 by an aldolase. ^[114]

Scheme 22

a) A nitrilase process (dynamic kinetic resolution)[ ¹⁰⁷ , ¹²⁰ ] and b) a related hydroxynitrile lyase process[ ¹¹³ , ¹²¹ ] for the synthesis of (R)‐mandelic acid and (R)‐o‐chloromandelic acid for the production of Clopidogrel 64.

Scheme 23

Nitrilase processes (desymmetrization) for the synthesis of a) ethyl (R)‐4‐cyano‐3‐hydroxybutyrate 66 for the production of Atorvastatin 18[ ¹⁰⁸ , ¹²³ ] and b) (S)‐3‐(4‐chlorophenyl)‐4‐cyanobutanoic acid 68 for the production of (R)‐Baclofen 69. ^[124]

Scheme 24

A nitrilase process (kinetic resolution) for the synthesis of (S)‐3‐cyano‐5‐methylhexanoic acid 71 for the production of Pregabalin, 72. ^[125]

Scheme 25

A nitrilase process (regioselective hydrolysis) for the synthesis of 1‐cyanocyclohexane acetic acid 74 for the production of Gabapentin 75. ^[109]

Scheme 26

A lipase‐catalyzed epimerization process (kinetic resolution) for the synthesis of (S)‐2‐carboxyethyl‐3‐cyano‐5‐methyl hexanoic acid 77 for the production of Pregabalin 72.[ ¹¹⁰ , ¹²⁹ ]

Scheme 27

A hydrolase‐based kinetic resolution process for the synthesis of the (R)‐succinic acid derivative 79 for the production of Brivaracetam 80. ^[111]

Scheme 28

A lipase‐based kinetic resolution process for the synthesis of the (2S, 3R)‐dimethyl‐1‐acetylpiperidine‐2,3‐dicarboxylate 81 for the production of Moxifloxacin 82.[ ¹¹² , ¹³⁰ ]

Scheme 29

Selective oxidation (desymmetrization) of glycerol 83 to d‐glyceric acid 84 by whole cells of acetic acid bacteria. ^[132]

Scheme 30

Cascade oxidation of 5‐hydroxymethylfurfural 85 to 2,5‐furan dicarboxylic acid 86 by multiple enzymes (dehydrogenases and/or oxidases) in vitro or in whole cells. ^[133]

Scheme 31

Cascade oxidation of cyclohexanol 87 to ϵ‐caprolactone oligomers 89 by a combination of an alcohol dehydrogenase, a Baeyer–Villiger monooxygenase, and a lipase with acyltransferase activity avoiding the formation of undesired 6‐hydroxy hexanoic acid. ^[135]

Scheme 32

Cascade oxidation of methyl myristate 90 to the corresponding ω‐hydroxyacid 91 or α,ω‐diacid 92 by Candida tropicalis containing P450s, oxidases, and ADHs. ^[139]

Scheme 33

Production of amide 95 from acid 93 and amine 94 using a combination of a CoA ligase (CBL) and a N‐acyltransferase (66CaAT).

Scheme 34

Production of amide 98 from acid 96 and amine 97 using the ATP‐dependent amide bond synthetase McbA and an ATP recycling system.

Scheme 35

Natural steviol glucosides.

Scheme 36

Sucrose synthase (SuSy)‐catalyzed recycling of nucleoside diphosphates such as UDP. ^[168]

Scheme 37

α‐Glycosylation using sucrose phosphorylase (SP).

Scheme 38

Direct and selective glucose transfer from sucrose 100 to glycerol using a sucrose phosphorylase. ^[171]

Scheme 39

Synthesis of Kojibiose with a sucrose phosphorylase (BaSP) and a glucose isomerase (GI). ^[172]

Scheme 40

Sucrase‐catalyzed conversion of sucrose to the α‐1,3‐polyglucan Mutan 105: an enzyme catalyzed polymerization.

Scheme 41

Norcoclaurine synthase (NCS)‐catalyzed reactions with a) production of (S)‐norcoclaurine; ^[188] b) expanded scope for different aldehydes; ^[189] c) expanded scope for different phenylethylamines and aldehydes. ^[190]

Scheme 42

Tryptophan synthase (TrpB)‐catalyzed C−C bond formation to produce a) β‐methyl tryptophan derivatives; ^[193] b) tryptophan derivatives with quaternary carbons. ^[194]

Scheme 43

An enzyme cascade with nine enzymes to produce Islatravir from simple starting materials. ^[195]

Scheme 44

An ex vivo enzyme cascade to produce Ikarugamycin 126 from simple starting materials. ^[199]

Scheme 45

An enzyme cascade comprising a carboxylic acid reductase (CAR), a transaminase (ATA) and an imine reductase (IRED) enables production of piperidines and pyrrolidines in high yield and optical purity. ^[205] (n=0, 1).

Scheme 46

A halide methyltransferase (HMT) converts S‐adenosyl homocysteine (SAH, 131) with methyl iodide into S‐adenosyl methionine (SAM, 132) serving as methyl donor for methyl transferases. ^[210]

Scheme 47

Demethylation was shown using several self‐sufficient P450‐monooxygenases for a range of methyl‐product aryl ketones ^[215] as well as for the demethylation of 6‐O‐methyl d‐galactose using an enzyme from a marine bacteria, which requires redox partner proteins (FoR, FoX). ^[214] These reactions yield formaldehyde as by‐product.

Scheme 48

Examples for regioselective halogenations using WelO15 ^[220] or WelO5* ^[221] (distinct mutants to afford either of the chlorinated products as indicated by the dashed bond) for chlorination, a ThaI variant for bromination ^[222] and VirX1 for iodination. ^[223]

Scheme 49

Synthesis of the fragrance citronellynitrile using a phenylacetoxime dehydratase (PAOx). ^[229]

Scheme 50

An aldoxime dehydratase (OxdA, used as whole cell system) catalyzes the stereoselective formation of a nitrile from the aldoxime. ^[231]

Scheme 51

Examples for “new‐to‐nature” chemistry catalyzed by engineered biocatalysts.