Industrial Biotransformations

3.20 Aromatics (Ring Functionalization)
Halogenations can be performed with electron-rich aromatics (amino or phenol derivatives)
using haloperoxidases or halogenases [56]. Alternatively, activated (acidic) C–H
bonds can also undergo halogenation.
3.20
Aromatics (Ring Functionalization)
HO
R
HO
R
O2N
R
OH
OH
OH OH
O
R
Xo
(ortho/para to -OH)
X o = NH, O (oxidized)
Xr = NH 2, OH (reduced)
R
oxygenase
dioxygenase
peroxidase
oxidase
peroxidase
Aromatics can be monooxygenated or dioxygenated using whole cell biotransformations.
Practical processes have been demonstrated for these conversions. This is the common
pathway for microorganisms to detoxify aromatics. Biaryl compounds can be prepared
from monomers by oxidative cross-coupling. Halogenations can be performed on
electron-rich aromatics (amino or phenol derivatives) using haloperoxidases [57].
R
X r
HO
R
OH
OH
R
R
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