A direct and efficient 3-halooxidation of indoles using DMSO as oxygen source

Here we develop a direct and efficient protocol for 3-halooxidation of indoles using DMSO as the oxygen source and NXS (X 1/4 Br, Cl) the halo source. This protocol features broad substrate scope and good to excellent yields, thus rendering it as a highly versatile, straightforward, and atom-economical alternative prior to the previously reported methods, which possess their capability to undergo the SN1 substitution of a highly reactive electrophilic o-azaxylylene intermediate to generate 3, 3-disubstituted oxindoles. (c) 2023 Elsevier Ltd. All rights reserved.