N-Aminopyridinium Ylide-Directed, Copper-Promoted Amination of sp2 C-H Bonds.
Se Hun KwakOlafs DaugulisPublished in: The Journal of organic chemistry (2019)
N-Aminopyridinium ylides are used as monodentate directing groups for copper-promoted C-H/N-H coupling of sp2 C-H bonds with pyrazoles, imidazoles, and sulfonamides. Reactions proceed in fluorinated alcohol solvents at elevated temperatures and require use of 1.3-3 equiv of copper(II) acetate. This appears to be the first method for copper-promoted C-H/N-H coupling directed by a removable monodentate auxiliary in absence of added ligands.