Highly Selective Addition of Organic Dichalcogenides to Carbon-Carbon Unsaturated Bonds.

Highly chemo-, regio- and/or stereoselective addition of organic dichalcogenides to carbon-carbon unsaturated bonds has been achieved based on two different methodologies for activation of the chalcogen-chalcogen bonds, i.e., by the aid of transition metal catalysts and by photoirradiation. The former is the novel transition metal-catalyzed reactions of organic dichalcogenides with acetylenes via oxidative addition of dichalcogenides to low valent transition metal complexes such as Pd (PPh3) 4. The latter is the photoinitiated radical addition of organic dichalcogenides to carbon-carbon unsaturated bonds via homolytic cleavage of the chalcogen-chalcogen bonds to generate the corresponding chalcogen-centered radicals as the key species.