Preparation of Dicationic Chalcogenolate-Bridged Diruthenium Complexes and Their Dual Catalytic Activity toward Reactions between Propargylic Alcohols and Acetone

Dicationic chalcogenolate-bridged diruthenium complexes have been newly prepared by reactions
of the neutral diruthenium dichloride complexes
[Cp*RuCl(μ2-YR)]2 (Y = S, Se, Te; R = Me, iPr) with 2
equiv of silver trifluoromethanesulfonate. Reactions of
propargylic alcohols with acetone in the presence of a
catalytic amount of these dicationic complexes afford the
corresponding hexadienones in moderate to good yields,
in sharp contrast to the formation of γ-ketoalkynes when
neutral or monocationic diruthenium complexes are
employed as catalysts.