Indole‐ and Pyrrole‐BX: Bench‐Stable Hypervalent Iodine Reagents for Heterocycle Umpolung

The one‐step synthesis of the bench‐stable hypervalent iodine reagents IndoleBX and PyrroleBX using mild Lewis acid catalyzed conditions is reported. The new reagents are stable up to 150 °C and were applied in the C−H arylation of unactivated arenes using either rhodium or ruthenium catalysts. A broad range of heterocyclic systems of high interest for synthetic and medicinal chemistry was accessed in high yields. The developed C−H functionalization could not be achieved using reported reagents or methods, highlighting the unique reactivity of Indole‐ and Pyrrole‐BX. Electrophilic Indoles/Pyrroles: The first synthesis of indole‐ and pyrrole‐derived benziodoxole reagents in one step from the heterocycles is reported. The new indole‐ and pyrrole‐BX reagents are stable up to 150 °C and can be used for selective heterocycle transfer onto the C−H bonds of arenes ortho to directing groups by using rhodium or ruthenium catalysts.