Download Application of "backdoor induction" in asymmetric catalysis

25th Croatian meeting of chemists and chemical engineers, Poreč, 2017.
Minimal Artificial Enzymes:
Application of "backdoor induction" in asymmetric catalysis
Minimalni umjetni enzimi:
Primjena posredne indukcije u asimetričnoj katalizi
Srećko I. Kirin
Ruđer Bošković Institute, HR-10000 Zagreb, Croatia
E-mail: [email protected]
The development of new small-molecule transition metal catalysts for asymmetric reactions
is often fuelled by imitating metalloenzyme active sites. Nevertheless, small-molecule
transition metal catalysts are still easily outperformed by metalloenzymes in terms of both
selectivity and reaction rates. It is obvious that mimicking the active site alone is not
sufficient to replicate metalloenzyme activity. Therefore we design artificial metalloenzymes
that contain not only an enzyme active site mimic but also a minimal functional outercoordination sphere. A major feature of these minimal artificial enzymes is "backdoor
induction" of chirality via hydrogen bonding and other non-covalent interactions between
distant chiral amide substituents, e. g. amino acids, diamines or dicarboxylic acids. Additional
favorable properties are cheap synthesis by standard chemical methods as well as possible
application to a broad range of substrates.
In this presentation, several selected approaches for the development of new
catalytic systems will be discussed [1]. Particular emphasis will be focused on
supramolecular systems comprising well defined artificial secondary structures [2], with the
potential to transmit chiral information from the outer-coordination sphere to the prochiral
catalytically active metal centre.
"backdoor induction"
L
R*
L
R*
L
R*
Mct
Mct
L
R*
prochiral
metal
chiral
substituents
Figure 1: Side view and top view of a supramolecular transition metal catalyst
(minimal artificial enzyme). The arrows indicate the sign of the helical chirality.
References
[1] (a) Z. Kokan, B. Perić, M. Vazdar, Ž. Marinić, D. Vikić-Topić, E. Meštrović, S. I. Kirin, Chem.
Commun., 53 (2017) 1945-1948; (b) Đ. Škalamera, E. Sanders, R. Vianello, A. Maršavelski, A. Pevec, I.
Turel, S. I. Kirin, Dalton Trans., 45 (2016) 2845-2858; (c) Z. Kokan, Z. Glasovac, M. Majerić Elenkov, M.
Gredičak, I. Jerić, S. I. Kirin, Organometallics, 33 (2014) 4005-4015; (d) Z. Kokan, S. I. Kirin, Eur. J. Org.
Chem., (2013) 8154-8161; (e) Z. Kokan, S. I. Kirin, RSC Adv., 2 (2012) 5729-5737.
[2] S. I. Kirin, H.-B. Kraatz, N. Metzler-Nolte, Chem. Soc. Rev., 35 (2006) 348-354.