Ruthenium-Catalyzed Vinylic Substitution Reactions with Nucleophiles via Butatrienylidene Intermediates

Novel ruthenium-catalyzed vinylic substitution reactions of vinylic trifluoromethanesulfonates with nucleophiles such as cyclic 1,3-diketones and alcohols have been found to give the corresponding vinylic-substituted products in good to high yields. This catalytic reaction is considered to be a new type of vinylic substitution reaction. Reactions of α-ketoacetylenes with alcohols have also been found to afford the corresponding vinylic ethers in good yields. These catalytic reactions can be explained to proceed by proposing ruthenium−butatrienylidene complexes as key intermediates. We believe that this finding will open up a further aspect of the chemistry of metal−cumulenylidene complexes.