Green One-Pot Syntheses of 2-Sulfoximidoyl-3,6-dibromo Indoles Using N -Br Sulfoximines as Both Brominating and Sulfoximinating Reagents.

A green one-pot 2,3,6-trifunctionalization of N -alkyl/aryl indoles was achieved by adding three equivalents of N -Br sulfoximine to the indole solution. A variety of 2-sulfoximidoyl-3,6-dibromo indoles were prepared with 38-94% yields using N -Br sulfoximines as both brominating and sulfoximinating reagents. Based on the results of controlled experiments, we propose that a radical substitution involving 3,6-dibromination and 2-sulfoximination occurs in the reaction process. This is first time that 2,3,6-trifunctionalization of indole in one pot has been achieved.