The Mizoroki-Heck reaction was applied to substrates derived from isocostic and ilicic acids, important sesquiterpene components of Dittrichia viscosa L. Greuter that were extracted directly from plant material collected in Morocco. After optimization of the metallo-catalysis conditions, various aryl-groups were successfully introduced on the exocyclic double bond with an exclusive E-configurat...

It is shown that two competitive pathways (T2 vs T4) exist for Grignard reagent formation. While the nonradical pathway T2 leads to retention of the configuration, the radical pathway T4 gives racemization. Our calculations suggest the way that T2 can be enhanced, which should be of significance to prompt new synthesis approaches for the preparation of chiral Grignard reagents.

Enantioselective resolution processes can be improved by integration of racemization. Applying environmentally friendly enzymatic racemization under mild conditions is in particular attractive. Owing to the variety enzymes and progress enzyme engineering, suitable racemases found for many chiral systems. An amino acid racemase (AAR) from P. putida KT2440 capable processing a broad spectrum acid...

With increase in age, proteins of the eye lens undergo covalent modifications associated with interprotein cross-linking, loss of protein solubility, generation of protein-associated pigments, and racemization of some optically active residues. Precipitated protein aggregates localized in the nucleus of brunescent lenses are modified to such an extent that they become resistant to the commonly ...

The chemoenzymatic dynamic kinetic resolution of β-amino esters is established after detailed evaluation metal-based heterogeneous catalysts for racemization and enzyme resolution.

The transfer and dynamic fixation of chirality in cyclic azobenzenes using R-(+)-1-phenylethylalcohol (R-PEA) and S-(-)-1-phenylethylalcohol (S-PEA) as solvents or additives are investigated. The cyclic azobenzenes used in this study carry a 1,5-dioxynaphthalene moiety as rotating unit, connected to the photoisomerizing (E-Z) azobenzene unit with spacers of varying lengths. With suitable length...