Catalytic Enantioselective Conjugate Alkynylation of β‑Aryl-β-trifluoromethyl Enones Constructing Propargylic All-Carbon Quaternary Stereogenic Centers

The enantioselective conjugate alkynylation of β-aryl-β-trifluoromethyl enones has been carried out using terminal alkynes and diethylzinc in the presence of 3,3′-bis­(perfluorophenyl)­BINOL as the chiral ligand to give the corresponding ketones bearing a trifluoromethylated propargylic quaternary stereocenter with fair to good enantioselectivities. Enones bearing a bulky 2-naphthyl attached to the carbonyl group provided the best enantioselectivities. The synthetic applicability of the resulting products has been demonstrated with their iodocyclization to form 4<i>H</i>-pyrans