Indol‐2‐ylidene (IdY): Ambiphilic N‐Heterocyclic Carbene Derived from Indole **

The synthesis of ambiphilic N‐heterocyclic carbene ligand, indol‐2‐ylidene (IdY, A ), is described. A series of indolenium precursors ( 2 a – f ) were prepared on a gram scale in good yields. Trapping experiments with elemental selenium, [RhCl(cod)] 2 and CuCl provided the expected carbene adducts. Further computational and spectroscopic studies supported the ambiphilicity of IdY, which lies between cyclic (alkyl)(amino)carbenes (CAAC‐5) and cyclic (amino)(aryl)carbene (CAArC). The copper complexes ( 6 ) show high percent buried volume (%  V bur = 58.1) and allow for carboboration of terminal alkynes within 30 minutes in a demonstration of synthetic utility with good yields and high regioselectivity.