Regiocontrolled Ru-catalyzed addition of carboxylic acids to alkynes: practical protocols for the synthesis of vinyl estersWe thank Prof. Dr. M. T. Reetz for generous support and constant encouragement, and gratefully acknowledge the DFG, the FCI, and the BMBF for financial support.

The catalytic activity of commercially available, air and water stable ruthenium complexes in the addition of carboxylic acids to terminal alkynes was found to be drastically enhanced by the addition of small quantities of base. Moreover, the regioselectivity of the reaction can be controlled by the choice of the base so that both the Markovnikov (Na2CO3) and the anti-Markovnikov products (DMAP) are now easily accessible in excellent selectivities.