Novel synthesis of chiral diferrocenyl dichalcogenides and their application to asymmetric reactions

Our recent studies on asymmetric reactions using chiral organochalcogen compounds are reviewed. Six chiral diferrocenyl dichalcogenides have been prepared from the corresponding chiral ferrocenes via diastereoselective lithiation followed by chalcogenation and oxidation in high yields. These dichalcogenides can be employed as reagents for new asymmetric reactions such as selenoxide elimination, [2,3]sigmatropic rearrangement of chiral selenoxides, telluroxides, selenimides and tellurimides, selenenylation of alkenes, and ring-opening reaction of meso-epoxides. These dichalcogenides, as well. as several newly prepared chiral ferrocenyl monochalcogenides, also act as chiral ligands in the rhodium- and iridium-catalyzed asymmetric hydrosilylation of ketones.