Rh(III)- or Ir(III)-catalyzed ynone synthesis from aldehydes via chelation-assisted C-H bond activation.

A Rh(III)- or Ir(III)-catalyzed direct aldehyde C-H alkynylation was developed for the first time as a simple and practical method for the synthesis of ynones. This catalytic reaction proceeds under mild reaction conditions and tolerates a variety of synthetically important functional groups (e.g., chloro, bromo, aldehyde), thus providing a good complement to previous methods.