This paper addresses the effects of the
concentration of lipases, temperature and solvent
on the enzymatic acetylation of primary amines.
(±)-Heptan-2-amine 1, (±)-4-phenylbutan-2-amine
2, (±)-1,2,3,4-tetrahydronaphthalen-1-amine 3 and
(±)-2-methylcyclohexan-1-amine 4 were acetylated using
11 lipases to obtain amides under orbital shaking and
microwave radiation. Under microwave radiation the
same amines were acetylated only using the CALB.
(±)-Heptan-2-amine 1 was subjected to kinetic resolution,
under orbital shaking for 7 h employing CALB and ethyl
acetate as acylating agent, and converted into (R)-N-
(heptan-2-yl)acetamide 5 (c = 42%, 88% eep, hexane c = 52%, 81% eep, isopropyl ether; c = 40%, 65% eep, toluene).
The reaction was fast (15 s) under microwave radiation in
hexane and yielded acetamide 4 in high conversion (c = 91%), but without selectivity (5% eep).