A ruthenium(ii)-catalyzed C-H allenylation-based approach to allenoic acids.

A Ru(ii)-catalyzed direct access to various functionalized allenoic acids via C-H allenylation of readily available aryl carboxylic acids with propargylic acetates is reported. Axially chiral allenoic acids could be obtained in high ee by using optically active propargylic acetates through a chirality transfer strategy.