Scheme 3.

Examples of regioselective ortho‐carboxylation of phenolic compounds catalyzed by recombinant E. coli whole cells containing a 2,3‐dihydroxybenzoic acid decarboxylase (2,3‐DHBD) reported by (a) Wuensch et al., ^[61] (b) Plasch et al., ^[63] and (c) Zhang et al. ^[64] 2,3‐DHBD_Ao=2,3‐dihydroxybenzoic acid decarboxylase from Aspergillus oryzae; 2,6‐DHBD_Rs=2,6‐dihydroxybenzoic acid decarboxylase from Rhizobium sp. and SAD_Tm=salicylic acid decarboxylase from Trichosporon moniliiforme. 2,3‐DHBD_Fo=2,3‐dihydroxybenzoic acid decarboxylase from Fusarium oxysporum. Conversion values (%) obtained with 2,3‐DHBD_Ao, 2,6‐DHBD_Rs, and SAD_Tm are given in black, blue, and pink, respectively.