Zinc triflate-mediated cyclopropanation of oxindoles with vinyl diphenyl sulfonium triflate: a mild reaction with broad functional group compatibility

The first use of zinc triflate for the cyclopropanation of unprotected oxindoles with vinyl diphenyl sulfonium triflate salt is reported. The reaction proceeded under ambient conditions and consistently provided high yields with broad functional group tolerability. The utility for the late-stage functionalization (LSF) of complex molecules is demonstrated.