Cobalt-promoted dimerization of aminoquinoline benzamides

Aminoquinoline-directed, cobalt-catalyzed carbonylation of sulfonamide sp2 C-H bonds

We report a method for cobalt-catalyzed, aminoquinoline-directed sp2 C-H bond carbonylation of sulfonamides. The reactions proceed in a dichloroethane solvent, and employ diisopropyl azodicarboxylate as a carbon monoxide source, Mn(OAc)2 as a cooxidant and potassium pivalate as a base. Halogen, ester, and amide functionalities are compatible with the reaction conditions. This method allows for a short and efficient synthesis of saccharin derivatives.

Efficient syntheses of 3-hydroxyimino-1-isoindolinones and 3-methylene-1-isoindolinones via Cu-promoted C–H activation–nitroalkylation–intramolecular cyclization tandem processes

Efficient and selective syntheses of 3-hydroxyimino-1-isoindolinones and 3-methylene-1-isoindolinones were achieved via 8-aminoquinoline assisted Cu-promoted coupling of benzamides with nitroalkanes.

Coordination strategy-induced selective C–H amination of 8-aminoquinolines

Using coordination-strategy, we realized a selective C–H amination of 8-aminoquinolins on the C5 position employing azoles as amines sources.

Cobalt-catalyzed aryl C–H activation and highly regioselective intermolecular annulation of sulfonamides with allenes

Cobalt(ii)-catalyzed C–H activation of aryl and heteroaryl sulfonamides and their intermolecular heteroannulation reaction with allenes was described providing a convergent strategy for the synthesis of biologically interesting heterocyclic scaffolds.

Amidines for Versatile Cobalt(III)-Catalyzed Synthesis of Isoquinolines through C-H Functionalization with Diazo Compounds

A cobalt(III)-catalyzed C-H/N-H bond functionalization for the synthesis of 1-aminoisoquinolines from aryl amidines and diazo compounds has been developed. The reaction proceeds under mild reaction conditions, obviates the need for oxidants, produces only N2 and H2O as the byproducts, and features a broad substrate scope.

Copper-catalyzed oxidative C-H/C-H cross-coupling of benzamides and thiophenes

A copper-catalyzed oxidative C-H/C-H cross-coupling of benzamides and thiophenes has been developed. This reaction exhibits a broad substrate scope and excellent tolerance of functional groups. The directing group could be readily removed to afford 2-thienylbenzoic acids.

Cobalt-Catalyzed, Aminoquinoline-Directed Functionalization of Phosphinic Amide sp2 C-H Bonds

In this paper, we introduce arylphosphinic acid aminoquinoline amides as competent substrates for cobalt-catalyzed sp² C-H bond functionalization. Specifically, the feasibility of their coupling with alkynes, alkenes, and allyl pivalate has been demonstrated. Reactions are catalyzed by simple Co(NO₃)₂ hydrate in ethanol or mixed dioxane/tBuOH solvent in the presence of Mn(OAc)₃·2H₂O additive, sodium pivalate, or acetate base and use oxygen from the air as an oxidant. Directing group removal affords ortho-functionalized P,P-diarylphosphinic acids.

Ligand-Enabled, Copper-Promoted Regio- and Chemoselective Hydroxylation of Arenes, Aryl Halides, and Aryl Methyl Ethers

We report here a practical method for the ortho C-H hydroxylation of benzamides with inexpensive copper(II) acetate monohydrate and a pyridine ligand. An intra- and intermolecular ligand combination was explored to achieve regio- and chemoselective hydroxylation. Interestingly, typical regiochemical scrambling associated with the C-H activation was further resolved by introducing a ligand-directed ortho hydroxylation of haloarenes and aryl methyl ethers.