Cu-Catalyzed C–N Coupling with Sterically Hindered Partners
Atanu Modak, Alex J. Nett, Elizabeth C. Swift, Michael C. Haibach, Vincent Chan, Thaddeus S. Franczyk, Shashank Shekhar, Silas P. Cook
Abstract
Copper, an earth-abundant metal, has reemerged as a viable alternative to the versatile Pd-catalyzed C–N coupling. Coupling sterically hindered reaction partners, however, remains challenging. Herein, we disclose the discovery and development of a pyrrole-ol ligand to facilitate the coupling of ortho-substituted aryl iodides with sterically hindered amines. The ligand was discovered through a library screening approach and highlights the value of mining heteroatom-rich pharmaceutical libraries for useful ligand motifs. Further evaluation revealed that this ligand is uniquely effective in these challenging transformations. The reaction enables the coupling of sterically hindered primary and secondary amines, anilines, and amides with broad functional group tolerance.