Generation of Quaternary\nCarbons in Cycloalkanones\nand Lactones with Arynes through a Domino Process

A synthetic method was developed for the generation of\na quaternary\ncarbon center in carbonyl compounds. This innovative process involved\nthe reaction of α-thiolate lactones and cycloalkanones with\ntwo equivalents of arynes in acetonitrile to give α,α-diarylated\nproducts in 63–85% yields at 25 °C. The reaction unfolds\nthrough an unconventional domino process, encompassing sequential\n1,2-elimination, 1,2-nucleophilic addition, 1,4-proton transfer, the\nsecond 1,2-nucleophilic addition, interrupted Pummerer rearrangement,\nintramolecular spirocyclization, and sulfonium ring-opening. The potential\nof this “single-flask” reaction was systematically investigated\nand found well-suited to generate diarylated carbonyl compounds, incorporating\nnaphthalene, pyridine, quinoline, or isoquinoline rings adorned with\nvarious substituents.