Nickel-Bound 5-Membered N-Heterocyclic Arynes: Access to Previously “Inaccessible” 7-Aza-2,3-indolynes

N-Heteroaromatics are key elements of life-saving pharmaceuticals, potent agrochemicals, and vital materials. N-Heteroarynes provide a scaffold to build these essential molecules but are underutilized because 5-membered N-heteroarynes have been computed to be inaccessible to synthetic chemists due to the strain of a triple bond in a 5-membered ring. Using principles of metal-ligand interactions that are foundational to organometallic chemistry, herein is reported the first access to a previously inaccessible 5-membered N-heteroaryne. A series of 1,2-bis(dicyclohexylphosphino)ethane nickel 7-azaindol-2,3-yne complexes are synthesized and characterized crystallographically and spectroscopically. In order to showcase the synthetic potential, a difunctionalization of N-methyl-7-azaindol-2,3-yne to form two new C-C bonds is performed. By overcoming a 120-year old limitation, we have unlocked a new synthon for the synthesis of difunctionalized N-heteroaromatics for transformative synthesis.