Methyltransferases: Green Catalysts for Friedel–Crafts Alkylations

A set of S-adenosyl-l-methionine (SAM) dependent methyltransferases has been characterized as versatile catalysts for the enzymatic Friedel-Crafts (alkylation) reaction. Although the substrate specificity of the enzymes range from high (in the case of SfmM2, SacF, and ORF19) to moderate (in the case of NovO and CouO), the cofactor spectrum is broad. Modified cofactors decorated with alkyl groups other than methyl were used for biocatalytic Friedel-Crafts alkylation, and conversions up to 99% were achieved. In contrast to the classical chemical reaction the biotransformation is very selective and environmentally compatible.