One-Step Ethynylation of Silyl Enol Ether with Chlorosilylethyne

In the presence of GaCl<sub>3</sub>, silyl enol ethers are ethynylated at the α-carbon atom with chlorotrimethylsilylethyne. This reaction can provide α-ethynylated aryl ketones possessing acidic α-protons without isomerization to conjugated allenyl ketones.