Asymmetric Synthesis

Stereoisomers are chemical compounds that have the same atomic connectivity but differ in their configuration, resulting in distinct properties. Asymmetric synthesis is an approach to synthesis that aims to produce compounds selectively. Asymmetric synthesis falls under the category of stereoselective reactions, where new chiral stereogenic units are introduced into the compound. These units can manifest as chiral center, axis, or plane. The key aspect of this reaction is the uneven formation of potential stereoisomers. Asymmetric synthesis plays a crucial role in organic chemistry, focusing on the development of molecules with precise stereostructures. This technique is particularly important for generating enantiomerically pure compounds, which are vital in various fields such as pharmaceutical development, agrochemical development, and materials science.

In the research fields of pharmaceuticals, agrochemicals, and functional materials, particularly in the development of ferroelectric liquid crystals, the demand for optically active compounds has significantly increased. To synthesize these desirable optically active compounds, diastereoselective and enantioselective reactions utilizing chiral auxiliaries and asymmetric catalysts are employed. To further enhance the optical purity and yield of target compounds, innovative chiral auxiliaries and asymmetric catalysts are continuously being developed, with numerous successful examples reported.

Various catalysts are utilized in asymmetric synthesis. For example, transition metal complexes containing central metals such as ruthenium, rhodium, and palladium are widely used. Numerous chiral ligands have also been developed to be used in conjunction with metal salts during the synthesis of these complexes. Additionally, there are instances where asymmetric reactions are catalyzed solely by organic compounds without the presence of metals, referred to as asymmetric organo-catalysts. Asymmetric organo-catalysts consist of organic small molecules that promote chirality; for instance, asymmetric aldol reactions using proline as a catalyst have been reported.