Stabilized pyrrolyl iodonium salts and metal-free oxidative cross-coupling

Pyrrole-aryl derivatives are important due to their unique biological activities in medicinal chemistry. We now report a new oxidative biaryl coupling for pyrroles and indoles toward various arenes using a hypervalent iodine reagent and an appropriate stabilizer for pyrrolyl iodonium intermediates. The reactions readily provide a variety of desired coupling products in good yields. We have developed a direct oxidative C-H bond arylation of pyrroles with various aromatic compounds via stabilized pyrrolyl iodonium( iii ) salts generated from modified hypervalent iodine( iii ) and TMSCl as an activator.