title: Copper-catalyzed site-selective intramolecular amidation of unactivated C(sp³)-H bonds.
abstract: The intramolecular dehydrogenative amidation of aliphatic amides, directed by a bidentate ligand, was developed using a copper-catalyzed sp(3) C-H bond functionalization process. The reaction favors predominantly the C-H bonds of β-methyl groups over the unactivated methylene C-H bonds. Moreover, a preference for activating sp(3) C-H bonds of β-methyl groups, via a five-membered ring intermediate, over the aromatic sp(2) C-H bonds was also observed in the cyclometalation step. Additionally, sp(3) C-H bonds of unactivated secondary sp(3) C-H bonds could be functionalized by favoring the ring carbon atoms over the linear carbon atoms.
authors.affiliation: Department of Chemistry and Chemical Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202 (USA).
authors.forename: Xuesong
authors.initials: X
authors.lastname: Wu
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Guangwu
authors.initials: G
authors.lastname: Zhang
authors.forename: Haibo
authors.initials: H
authors.lastname: Ge
keywords: CH activation; copper; heterocycles; homogeneous catalysis; synthetic methods