Preparation of Dicationic Chalcogenolate-Bridged Diruthenium Complexes and Their Dual Catalytic Activity toward Reactions between Propargylic Alcohols and Acetone
摘要:
Dicationic chalcogenolate-bridged diruthenium complexes have been newly prepared by reactions of the neutral diruthenium dichloride complexes [CP*RUCl(mu(2)-YR)](2) (y = S, Se, Te; R = Me, Pr-i) 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 gamma-ketoalkynes when neutral or monocationic diruthenium complexes are employed as catalysts.
chalcogenolate(Se,Te)-bridged dirutheniumcomplexes (neutral and cationic) as well as their allenylidenecomplexes have been newly prepared, and their catalytic activities toward the propargylicsubstitutionreactions have been compared with those using the corresponding thiolate(S)-bridged complexes. Results of both catalytic and stoichiometric reactions using these complexes together with their redox