Biocatalytic Friedel–Crafts Acylation and Fries Reaction

Abstract

The Friedel-Crafts acylation is commonly used for the synthesis of aryl ketones,and abiocatalytic version, which may benefit from the chemo-and regioselectivity of enzymes, has not yet been introduced. Described here is ab acterial acyltransferase which can catalyze Friedel-Crafts C-acylation of phenolic substrates in buffer without the need of CoAactivated reagents.C onversions reach up to > 99 %, and various C-or O-acyl donors,s uch as DAPG or isopropenyl acetate,are accepted by this enzyme.Furthermore the enzyme enables aF ries rearrangement-like reaction of resorcinol derivatives.These findings open an avenue for the development of alternative and selective CÀCbond formation methods.

Molecular cloning, expression, and characterization of acyltransferase from Pseudomonas protegens

“…For the evaluation of pH, the model substrate was changed to resorcinol (Fig. 6 ), since we were interested to apply this enzyme for various acyl donors and acceptors (Schmidt et al 2017 ). Thus, the ATase activity in the following studies was evaluated based on the formation of the C-acetyl product 9 arising from the bioacetylation of model substrate 8 by DAPG.…”

“…HCl (3.6 vol%), trans -cinnamaldehyde (3.6 vol%)]. Shake flask cultivation, expression of the wild-type, and recombinant ATase was performed as described previously (Schmidt et al 2017 ).…”

“…2 ) into one molecule of PG ( 7 ) and DAPG ( 5 ) in the forward reaction (Hayashi et al 2012 ; Yang and Cao 2012 ; Almario et al 2017 ). Our previous report proved that a multi-component ATase from Pseudomonas protegens catalyzes transfer of acyl moieties, not only from natural but also from non-natural donor substrates, to the aromatic ring of a phenolic acceptor substrate by forming a new C-C bond in a Friedel-Crafts-type acylation reaction (Schmidt et al 2017 ). In this work, we report on the cloning of the key biosynthetic operon phlACB , into a bacterial expression vector to produce the ATase in E. coli and developed optimal conditions for robust synthesis of this enzyme.…”

Decarboxylative Acylation of Carboxylic Acids: Reaction Investigation and Mechanistic Study

“…[5][6][7][8][9][10] The combination of photoredox/nickel catalysis recently initiated by MacMillan 11 and Molander 12 has led to advances in redoxneutral chemical bond formation. [13][14][15][16][17][18][19][20] In this context, several research groups [21][22][23][24] have reported elegant examples of metallaphotoredox-catalyzed C(sp 3 )-H acylation with amides, anhydrides or activated 2-pyridylthioesters as acyl surrogates. In these reactions, substrates such as compounds with an -C(sp 3 )-H adjacent to heteroatom or simple alkanes have been employed to cause a facile HAT process and thus control the regioselectivity.…”

“…[13][14][15][16][17][18][19][20] In this context, several research groups [21][22][23][24] have reported elegant examples of metallaphotoredox-catalyzed C(sp 3 )-H acylation with amides, anhydrides or activated 2-pyridylthioesters as acyl surrogates. In these reactions, substrates such as compounds with an -C(sp 3 )-H adjacent to heteroatom or simple alkanes have been employed to cause a facile HAT process and thus control the regioselectivity. There is still, however, a great demand for the development of a practical protocol using a readily available chemical as an alkyl radical source, [25][26][27] with the aim to construct complex ketones without redundant protection and deprotection process.…”