Artificial metalloenzymes, deriving from transition metal catalysts embedding within a biological environment, have recently risen up as a promising synthetic tool able to combine the reactivity of metal-based catalysis with the specificity of biocatalysis.1 Dalbapeptides, such as vancomycin, teicoplanin and ristocetin are variously substituted heptapeptides whose antibiotic activity relies on their binding to the D-Ala-D-Ala dimer of peptidoglycan precursors thus leading to an irreversible inhibition of cell wall biosynthesis. This interaction is marked by such a low dissociation constant (KD =~10-17M) that it makes vancomycin-based systems an innovative alternative to the classical biotin/(strept)avidin technology.2,3 In this context, a class of aminoethylbenzensulfonamide ligands functionalized with the D-Ala-D-Ala dimer were employed for the synthesis of hybrid catalysts in association with an iridium centre. In the presence of vancomycin, a new class of artificial reductases was obtained and applied to the Asymmetric Transfer Hydrogenation (ATH) of model imine substrates in different aqueous media. An encouraging 48% (S) e.e. was obtained in the asymmetric reduction of the salsolidine precursor in CH3COONa 0.1 M buffer at pH 5 whereas in the case of quinolines, the meta-artificial metalloenzyme afforded the product in a significant 70% (S) e.e. when applied to quinaldine. Moreover, an unprecedented 35% (R) e.e. in the enantioselective reduction of chiral sultam precursor 3-methylbenzo[d]isothiazole-1,1-dioxide was realized under green reaction conditions.
New artificial imine reductases based on an iridium/ vancomycin system for the asymmetric reduction of cyclic imines / G. Facchetti, I. Rimoldi - In: New Directions and Perspectives on Organometallic Chemistry[s.l] : University of Camerino, 2021. - ISBN 9788867680528. - pp. 26-26 (( Intervento presentato al 13. convegno International School of Organometallic Chemistry tenutosi a Webinar on line nel 2021.
|Titolo:||New artificial imine reductases based on an iridium/ vancomycin system for the asymmetric reduction of cyclic imines|
FACCHETTI, GIORGIO (Primo) (Corresponding)
RIMOLDI, ISABELLA (Ultimo)
|Settore Scientifico Disciplinare:||Settore CHIM/03 - Chimica Generale e Inorganica|
|Data di pubblicazione:||2021|
|URL:||https://isoc.unicam.it/sites/d7.unicam.it.isoc/files/Proceedings ISOC 2021.pdf|
|Tipologia:||Book Part (author)|
|Appare nelle tipologie:||03 - Contributo in volume|