Recent Advances in Selected Asymmetric Reactions Promoted by Chiral Catalysts: Cyclopropanations, Friedel–Crafts, Mannich, Michael and Other Zinc-Mediated Processes—An Update

The main purpose of this review article is to present selected asymmetric synthesis reactions in which chemical and stereochemical outcomes are dependent on the use of an appropriate chiral catalyst. Optically pure or enantiomerically enriched products of such transformations may find further applications in various fields. Among an extremely wide variety of asymmetric reactions catalyzed by chiral systems, we are interested in: asymmetric cyclopropanation, Friedel–Crafts reaction, Mannich and Michael reaction, and other stereoselective processes conducted in the presence of zinc ions. This paper describes the achievements of the above-mentioned asymmetric transformations in the last three years. The choice of reactions is related to the research that has been carried out in our laboratory for many years.

Role of Additives to Overcome Limitations of Intermolecular Rhodium-Catalyzed Asymmetric Cyclopropanation

This study describes general methods for the enantioselective syntheses of disubstituted cyclopropane carboxylates including substitution patterns or heterocycle functionality previously observed as significant limitations. The key step is the dirhodium tetracarboxylate-catalyzed asymmetric cyclopropanation of vinyl arenes with aryl- or heteroaryldiazoacetates. The reactions are highly diastereoselective and high asymmetric induction could be achieved using either (<i>R</i>)-pantolactone as a chiral auxiliary or chiral dirhodium tetracarboxylate catalysts.

Role of Additives to Overcome Limitations of Intermolecular Rhodium-Catalyzed Asymmetric Cyclopropanation

This study describes general methods for the enantioselective syntheses of disubstituted cyclopropane carboxylates including substitution patterns or heterocycle functionality previously observed as significant limitations. The key step is the dirhodium tetracarboxylate-catalyzed asymmetric cyclopropanation of vinyl arenes with aryl- or heteroaryldiazoacetates. The reactions are highly diastereoselective and high asymmetric induction could be achieved using either (<i>R</i>)-pantolactone as a chiral auxiliary or chiral dirhodium tetracarboxylate catalysts.

Design and Characterization of Novel Dirhodium Coordination Polymers - The Impact of Ligand Size on Selectivity in Asymmetric Cyclopropanation

Three chiral dirhodium coordination polymers Rh2-Ln (n=1-3) have been synthesized via ligand exchange between dirhodium trifluoroacetate Rh2(TFA)4 and differently sized chiral dicarboxylic acids derived from L-tert-leucine. SEM images indicate that...

Asymmetric synthesis of pharmaceutically relevant 1-aryl-2-heteroaryl- and 1,2-diheteroarylcyclopropane-1-carboxylates

The dirhodium tetracarboxylate-catalysed asymmetric cyclopropanation has been applied to the enantioselective syntheses of pharmaceutically relevant 1-aryl-2-heteroaryl- and 1,2-diheteroarylcyclopropane-1-carboxylates.