Copper-catalysed selective 3-sulfonylation of indoles: a mild synthesis of indolyl sulfones

The selective C3-sulfonylation of some 4-, 5- and 6-substituted indoles using sodium arenesulfinates as reaction partners has been realised under mild conditions using catalytic CuI/1,10-phenanthroline at 70 degrees C. The reaction had a satisfactory application scope and proceeded in fair to excellent yields.