Chiral auxiliaries as docking/protecting groups: biohydroxylation of selected ketones with Beauveria bassiana ATCC 7159

The taming of oxygen: biocatalytic oxyfunctionalisations

The scope and limitations of oxygenases as catalysts for preparative organic synthesis is discussed.

Dramatic Enhancement of Enantioselectivity of Biotransformations of β-Hydroxy Nitriles Using a Simple O-Benzyl Protection/Docking Group

[Structure: see text] Catalyzed by the Rhodococcus erythropolis AJ270 whole cell catalyst, the O-benzylated beta-hydroxy alkanenitriles underwent remarkably high enantioselective biotransformations, whereas the biotransformations of free beta-hydroxy alkanenitriles gave very low enantioselectivity. The easy manipulations of O-protection and O-deprotection, excellent chemical and enantiomeric yields of biotransformations, along with the scalability render this enzymatic transformation attractive and practical for the synthesis of highly enantiopure beta-hydroxy alkanoic acids and their amide derivatives.

The use of substrate engineering in biohydroxylation

In the biohydroxylation of nonactivated carbon atoms, substrate engineering has been found to be a very useful and simple means to influence substrate acceptance and the regioselectivity and stereoselectivity of this transformation. Recently, this methodology has been applied to the hydroxylation of a large number of compounds including cycloalkane carboxylic acids, ketones, amines, amides and alcohols.

Oxidative biotransformations using oxygenases

Considerable progress has been made in manipulating oxidative biotransformations using oxygenases. Substrate acceptance, catalytic activity, regioselectivity and stereoselectivity have been improved significantly by substrate engineering, enzyme engineering or biocatalyst screening. Preparative biotransformations have been carried out to synthesize useful pharmaceutical intermediates or chiral synthons on the gram to several-hundred-gram scale, by use of whole cells of wild type or recombinant strains. The synthetic application of oxygenases in vitro has been shown to be possible by enzymatic or electrochemical regeneration of NADH or NADPH.