A dinuclear ruthenium catalyst with a confined cavity: selectivity in the addition of aliphatic carboxylic acids to phenylacetylene

A dinuclear ruthenium catalyst with a rigid anthracene spacer shows excellent regio- and stereo-selectivity in the atom-economic addition of aliphatic carboxylic acids to phenylacetylene, producing exclusively anti-Markovnikov enol-esters with high E/Z ratios of the isomers.