chemia - Studia

STUDIA UBB. CHEMIA, LV, 4, 2010
SYNTHESIS AND LIPASE CATALYSED KINETIC RESOLUTION
OF RACEMIC AMINES
PÉTER FALUS a , ZOLTÁN BOROS a , GÁBOR HORNYÁNSZKY a , JÓZSEF
NAGY a , LÁSZLÓ ÜRGE b , FERENC DARVAS c , LÁSZLÓ POPPE a *
ABSTRACT. Feasibility of production of amines from ketones employing
metal and/or metal-catalysts in one-pot and one-step reductive amination
(modified Leuckart- and Leuckart-Wallach- reaction) and lipase catalysed
kinetic resolution of racemic amines in batch and continuous-flow reactor were
investigated. In kinetic resolutions the effect of the solvent, the acetylating
agent and the lipase itself was examined.
Keywords: reductive amination, metal-catalysis, lipase, continuous-flow reactor,
kinetic resolution
INTRODUCTION
Enantiomerically pure chiral amines are valuable building blocks of
quite a number of drugs [1], pesticides [2] and colour pigments [3]. Considerable
amount of drugs are amines or amine derivatives.
Biotechnology and biocatalysis are increasingly employed to produce
optically active intermediates of drugs [4]. Hydrolases can be efficiently used for
synthetic biotransformations due to its favourable characteristics [5, 6, 7, 8].
Hydrolases can catalyze several related reactions such as hydrolysis,
condensations, alcoholysis and aminolysis. Lipases are proved to be highly
versatile biocatalyst in stereoselective biotransformations such as kinetic
resolutions [9], deracemisations and dynamic kinetic resolutions [10].
Enantioselective enzymatic reactions are typically carried out in batch mode
[5, 9, 11, 12], however a few studies state these are feasible in continuousflow
system [13, 14, 15, 16].
RESULTS AND DISCUSSION
In our previous work, one-step reductive amination of various ketones
was examined [17]. It was found that in those cases when the carbonyl-group
is at α-position from an aromatic or heteroaromatic ring Zn dust promoted
reactions gave the corresponding amines without notable side reactions, whereas
in the case of aliphatic and cycloaliphatic ketones 10% Pd/C-catalysis was
suitable.
a Budapest University of Technology and Economics, Department of Organic Chemistry and
Technology, and Research Group for Alkaloid Chemistry of HAS, Műegyetem rkp 3, H-1111,
Budapest, Hungary, * poppe@mail.bme.hu
b ThalesNano Inc., Graphisoft Park, Záhony u. 7., H-1031 Budapest, Hungary
c Department of Cellular Biology and Pharmacology, Herbert Weinheim College of Medicine,
Florida International University, 11200 S.W. 8th Street, Miami, FL 33199, USA