Enantioselectivity genetic optimization

Fig. 2 Biotin-avidin technology Artificial metalloenzymes [M(L )(biotin-ligand)]c(strept)avidin for enantioselective catalysis are based on the anchoring of a catalyticaUy active metal fragment within a host protein via a hgand, a spacer, and biotin. Chemical optimization can be achieved either by varying the spacer or the metal chelate moiety ML ). Saturation mutagenesis at a position close to the metal moiety ( ) can be used for genetic optimization...

The enantioselectivity of a biocatalytic resolution or asymmetrization is primarily dependent on the enzyme and the structure of the substrate. Both of these can be changed in order to optimize the selectivity. The enzyme can be optimized by molecular genetic methods, while the substrate can be modified by organic chemical synthesis. These ways of optimizing selectivity will not be discussed in this chapter. 

Genet, Darses, and coworkers reported an interesting enantioselective rhodium-catalyzed 1,4-addition of organotin reagents to electron-deficient a,a -disubstituted alkenes, to afford amino ester derivatives (Scheme 5.18). Indeed, it appeared that their optimized conditions, involving BINAP as the ligand for rhodium and guaiacol, as the proton source worked well for dehydroamino ester derivatives [61]. 

Ratovelomanana-Vidal V, Girard C, Touati R, Tranchier IP, Ben Hassine B, Genet JP. Enantioselective hydrogenation of (3-keto esters using chiral diphosphine-ruthenium complexes optimization for academic and industrial purposes and synthetic applications. Adv. Synth. Catal. 2003 345(l-2) 261-274. 

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