A direct synthesis of lactams (5-, 6-, and 7-membered) starting from amino-alcohols in a bienzymatic cascade is reported. Horse liver alcohol dehydrogenase together with the NADH oxidase from Streptococcus mutans were applied for the oxidative lactamization of various amino alcohols. Crucial parameters for the efficiency of this cascade reaction were elucidated. This report represents a direct approach for biocatalytic oxidative lactamization reaction.

A nicotinamide adenine dinucleotide (NADH)-dependent redox-neutral convergent cascade composed of a recently discovered type II flavin-containing monooxygenase (FMO−E) and horse liver alcohol dehydrogenase (HLADH) has been established. Two model reaction cascades were analyzed for the synthesis of γ-butyrolactone and chiral bicyclic lactones. In the former cascade, all substrates were converted into one single product γ-butyrolactone with high atom efficiency. More than 130 mM γ-butyrolactone were obtained when applying 100 mM cyclobutanone and 50 mM 1,4-butanediol in this cascade. In the second cascade where bicyclo[4.2.0]octan-7-one and cis-1,2-cyclohexanedimethanol were coupled, the ketone substrate was converted to the corresponding normal lactone with an ee value of 89–74% (3aS, 7aS) by FMO−E alone and the abnormal lactone with an ee value of >99% (3aR, 7aS) was formed by both HLADH and FMO−E. (Figure presented.).