Naslov
"Backdoor induction" of chirality in asymmetric hydrogenation with rhodium(I) complexes of amino acid substituted triphenylphosphane ligands
("Backdoor induction" of chirality in asymmetric hydrogenation with rhodium(I) complexes of amino acid substituted triphenylphosphane ligands")

Autori
Kokan, Zoran ; Kirin, Srećko I.

Izvornik
European journal of organic chemistry (1434-193X) 2013 (2013), 36; 8154-8161

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
amino acids; artificial metalloenzymes; asymmetric catalysis; metallated bioconjugates; supramolecular chemistry

Sažetak
This paper describes the synthesis and characterization of 5-(di-phenylphosphino)isophthalic acid bioconjugates, Lig-[R]2. In addition to symmetrically disubstituted conjugates with amino acids (1a-1e and 4f-4g), peptides (2a-2e and 3a-3b) or amines (4a-4e), a convenient one pot two step procedure for the synthesis of conjugates 5a-g bearing two different substituents is reported. The 28 prepared phosphanes 1-5 are used as monodentate ligands in the rhodium(I) catalyzed hydrogenation of 2-acetamidoacrylate or (Z)-(alpha)-acetamidocinnamate. Ligand with small side chain substituents Lig-[Ala-OMe]2 1a revealed highest selectivity with up to 84 % ee. The catalysts presented herein are models of artificial metalloenzymes where the secondary coordination sphere controls the selectivity in catalysis. The chirality of distant hydrogen-bonded amino acids is transmitted by "backdoor induction" to the prochiral Rh(I).

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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