Oxidative Coupling of Terminal Alkyne with α‑Hydroxy Ketone: An Expedient Approach toward Ynediones

An efficient and mild copper-catalyzed
one-pot approach toward
ynediones has been established. A variety of ynediones were constructed
directly through oxidative coupling of alkyne with α-hydroxy
ketone. Oxygen-oxidizing and neutral conditions in one-pot for a wide
range of substrates including natural product derivatives make this
transformation highly efficient and practical. On the basis of control
experiments, in situ IR measurements, and isotopic
labeling experiments, a plausible mechanism involving intermediate
phenylglyoxal was drawn. Applications by synthesis of various heterocycles
were also investigated.