Hypervalent Chalcogenonium⋅⋅⋅π Bonding Catalysis.

A proof-of-concept study of hypervalent chalcogenonium⋅⋅⋅π bonding catalysis was performed. A new catalytic strategy using 1,2-oxaselenolium salts as chalcogen bond donors and alkenes as chalcogen bond acceptors is described. The feasibility of this concept is demonstrated by the use of trisubstituted selenonium salts in the metal-free catalytic hydrofunctionalization and polymerization of alkenes via unconventional seleniranium ion-like intermediates. The results indicate that counter anions have a significant effect on the catalysis based on hypervalent chalcogenonium⋅⋅⋅π bonding interactions.