Indol-2-Ylidene (IdY): A New Ambiphilic N-Heterocyclic Carbene Derived from Indole

Abstract

The ambiphilic N-heterocyclic carbene ligand, indol-2-ylidene (IdY, <b>A</b>), is described. A series of indolenium precursors (<b>2a</b>-<b>f</b>) were prepared on a gram scale in good yields. Trapping experiments with elemental selenium, [RhCl(cod)]<sub>2</sub> and CuCl lead to IdY-supported materials, respectively. Computational and spectroscopic studies revealed the ambiphilicity of IdY. The copper complexes (<b>6</b>) show high percent buried volume (%V<sub>bur</sub> = 58.1) and allow for carboboration of terminal alkynes within 30 minutes as synthetically useful yields and high regioselectivity.