Rhodium( <scp>iii</scp> )-catalyzed direct C–H activation of 2-aryl-3 <i>H</i> -indoles: a strategy for 4-heteroaryl pyrazole synthesis

A novel protocol for synthesizing 4-heteroaryl pyrazoles from readily available 2-aryl-3<i>H</i>-indoles and diazopyrazolones through the rhodium(III)-catalyzed C-H bond activation has been achieved. This redox-neutral strategy features powerful reactivity, tolerates various functional groups, and proceeds with moderate yields under mild reaction conditions.