Copper-Catalyzed, Ligand-Controlled N(sp3)- or N(sp)-Selective Arylation of Cyanamides

Org Lett. 2023 Sep 1;25(34):6446-6451. doi: 10.1021/acs.orglett.3c02622. Epub 2023 Aug 23.

Abstract

Cyanamides possess both nucleophilic and electrophilic centers, and their arylation reactions are known to proceed at N(sp3) and C(sp) sites, leading to N-aryl cyanamides or amidines. N(sp) selectivity has also been reported only in the presence of amines, thus leading to guanidines. Herein, we report a general copper-catalyzed ligand-controlled Chan-Lam-Evans arylation of cyanamides proceeding regioselectively at the N(sp3) or N(sp) atoms and leading to either N-aryl cyanamides or dissymmetric carbodiimides. The nature of the ligand, either a bipyridine or a diamine, controls the product distribution and thus offers a divergent entry to useful building blocks from readily available cyanamides.