An efficient and convenient ligand-free, rhodium-catalyzed ortho-C(sp2)-H amidation of benzaldehydes with dioxazolones using H2O as the key promoter is described. Using this protocol, a wide range of benzaldehyde substrates were selectively amidated in good to excellent yields with broad functional group compatibility. KIE experiments revealed that the C-H bond activation was likely the rate-limiting step. In addition, computational studies indicated that the catalyst precursor interacted with water and dioxazolones to generate the active catalytic species. Notably, the practicality and efficacy of this method were illustrated by a late-stage amidation of an estrone-derived molecule and further transformations of the amidated product.

Nonbiaryl N-C atropisomer is an important structural scaffold, which is present in natural products, medicines and chiral ligands. However the direct enantioselective C-H amination to access optically pure N-C atropisomer is still difficult and rare. Here we report a π-π interaction and dual H-bond concerted control strategy to develop the chiral phosphoric acids (CPAs) catalyzed direct intermolecular enantioselective C-H amination of N-aryl-2-naphthylamines with azodicarboxylates as amino sources for the construction of atroposelective naphthalene-1,2-diamines. This type of N-C atropisomers is stabilized by intramolecular hydrogen bond and the method features a broad range of substrates, high yields and ee values, providing a strategy to chirality transfer via the modification of N-C atropisomers.

A metal-controlled, regioselective intermolecular amination of unsaturated N-acylpyrazoles with azodicarboxylates is described. Under zinc catalysis, the N-acylpyrazole substrates undergo amination at the α-position of the N-acylpyrazole moiety. Conversely, with silver as the catalyst, the reaction gave γ-amination products. Both catalytic protocols provided alternative, convenient, and simple strategies for efficiently and regioselectively accessing structurally unique C-N-bond containing compounds. The synthetic utility of this method was illustrated by a gram-scale experiment and subsequent efficient synthesis of the γ-amino acid analogue.

An efficient and convenient method enabling direct amination of unactivated methylene C(sp 3 )−H bonds to form C−N bonds with azodiformates as amino source is described. This method highlights the emerging strategy of unactivated methylene as versatile functional groups in organic synthesis and provides a strategy to construct functionalized C−N bonds for the synthesis of complex molecules.

A Rh(III)-catalyzed cascade [3 + 2] annulation of Nphenoxyacetamides with propiolates under mild conditions using the internal oxidative O−N bond as the directing group has been achieved. This catalytic system provides a regio-and stereoselective access to benzofuran-2(3H)-ones bearing exocyclic enamino motifs with exclusive Z configuration selectivity, acceptable to good yields and good functional group compatibility. Mechanistic investigations by experimental and density functional theory studies suggest that a consecutive process of C−H functionalization/isomerization/lactonization is likely to be involved in the reaction.