Enantioselektivní

Enantioselektivní is a Czech adjective derived from the English term enantioselective, which refers to a chemical reaction that selectively produces one enantiomer of a chiral product over the other. In stereochemistry, an enantiomer is a mirror-image isomer that cannot be superimposed, and the ability of a reaction to favor one over the other is measured by enantiomeric excess (ee). The term is widely used in organic synthesis, pharmaceutical chemistry, and catalysis to denote processes that exploit chiral induction, either through chiral catalysts, reagents, or substrates, to achieve high selectivity.

There are several experimental strategies to achieve enantioselectivity. Chiral Lewis or Brønsted acid catalysts can coordinate to a substrate and create a preferential orientation for bond formation. Organocatalysis employs small organic molecules such as proline derivatives or BINOL‑based phosphoric acids. Transition‐metal complexes with chiral ligands, for instance with chiral phosphine or N,N‑ligands, are common in asymmetric hydrogenation and cross‑coupling reactions. In addition, chiral auxiliaries – temporary chiral groups that are attached and later removed – allow for highly selective transformations when catalytic methods are not yet suitable.

Enantioselective synthesis is critical in the pharmaceutical industry, where one enantiomer of a drug is often therapeutically active while the other may be inactive or harmful. The ability to produce single‑enantiomer drugs enhances efficacy, reduces side effects, and can improve regulatory approval prospects. Other related terms include kinetic resolution, which separates enantiomers based on different reaction rates, and diastereoselective synthesis, which deals with the formation of diastereomers rather than enantiomers. The development of efficient enantioselective methods remains a central challenge in modern synthetic chemistry.