Diarylamine Synthesis via Desulfinylative Smiles Rearrangement

Cu-Catalyzed Synthesis of Symmetric Diarylamines from Organoboronic Acids Using NaNO2 as the Amino Source

A copper-catalyzed novel synthesis of symmetric diarylamines was achieved from aryl boronic acids and NaNO2. This protocol employs aryl boronic acids as the commercially available arylation reagents and sodium nitrite (NaNO2) as the cheap, stable, and solid amino source. Under a simple ligand- and base-free copper catalytic system (CuCl as the sole catalyst), a wide range of symmetric diarylamines could be obtained in moderate to good yields. Notably, the use of Na15NO2 could produce 15N-labeled diarylamines, which would otherwise be difficult to prepare by the known methods.

Copper-Catalyzed One-Pot Protocol for Reductive N-Arylation of Nitroarenes with (Hetero)aryl Chlorides in Water

A novel protocol for the Cu-catalyzed reductive N-arylation of nitroarenes with (hetero)aryl chlorides in water has been realized. Combining N-(9H-carbazol-9-yl)-6-hydroxypicolinamide (L2) with oxalohydrazide is vital to realize the method at 90 °C with a loading of 5 mol % of Cu2O/L2. Various nitroarenes and aryl chlorides have been successfully coupled in good to excellent isolated yields. Further, two diarylamine-containing key intermediates, 3f and 4u, have been smoothly synthesized on a gram scale using this method.

Synthesis of Diarylamines via Nitrosonium-Initiated C-N Bond Formation

Electron-rich diarylamines, exemplified by anisole-derived amines, play pivotal roles in process chemistry, pharmaceuticals, and materials. In this study, homo-diarylamines were synthesized directly from the C-H activation of electron-rich arenes by sodium nitrate/trifluoroacetic acid and the successive treatment of iron powder. Mechanistic investigations reveal that nitrosoarene serves as the reaction intermediate, and the formation of the second C-N bond between the resulting nitrosoarene and electron-rich arene is catalyzed by the nitrosonium ion (NO+). Thus, hetero-diarylamines were synthesized using preformed nitrosoarenes and various electron-rich arenes. This reaction complements a range of cross-coupling reactions catalyzed by transition metal catalysts.

A general alkene aminoarylation enabled by N-centred radical reactivity of sulfinamides

Arylethylamines are popular structural elements in bioactive molecules but are often made through a linear series of synthetic steps. A modular protocol to assemble arylethylamines from alkenes in one step would represent a useful advance in discovery chemistry, though current limitations preclude a generally applicable method. In this work we disclose an aminoarylation of alkenes using aryl sulfinamide reagents as bifunctional amine and arene donors. This reaction features excellent regioselectivity and diastereoselectivity on a variety of activated and unactivated substrates. Using a weakly oxidizing photocatalyst, a nitrogen radical is generated under mild conditions and adds to an alkene to form a new C-N bond. A desulfinylative aryl migration event known as a Smiles-Truce rearrangement follows to form a new C-C bond. In this manner, arylethylamines can be rapidly assembled from abundant alkene feedstocks. Moreover, chiral information from the sulfinamide can be transferred via rearrangement to a new carbon stereocentre in the product, thus advancing the development of traceless asymmetric alkene difunctionalization.

Excited-State Nickel-Catalyzed Amination of Aryl Bromides: Synthesis of Diphenylamines and Primary Anilines

Excited-state nickel-catalyzed C-N cross-coupling of aryl bromides with sodium azide enables the synthesis of diarylamines and primary anilines under mild reaction conditions. The oxidative addition of electron-rich aryl bromides with low-valent Ni under the photochemical conditions is endothermic. Herein, we demonstrate a light-mediated nickel-catalyzed reaction of electronically rich aryl bromides that yields diarylamines, while the reaction with electron-deficient aryl bromides gives access to anilines at room temperature.

Synthesis of Functionalized Pyrrolidinone Scaffolds via Smiles-Truce Cascade

Arylsulfonamides have been found to react with cyclopropane diesters under simple base treatment to give α-arylated pyrrolidinones. This one-pot process comprises three steps: nucleophilic ring-opening of the cyclopropane, reaction of the resulting enolate in a Smiles-Truce aryl transfer, and lactam formation. The reaction represents a new, operationally simple approach to biologically active pyrrolidinones and expands Smiles-Truce arylation methods to encompass sp3 electrophilic centers in cascade processes.

An NHC-Catalyzed Desulfonylative Smiles Rearrangement of Pyrrole and Indole Carboxaldehydes

The use of catalysis methods to enable Smiles rearrangement opens up new substrate classes for arylation under mild conditions. Here, we describe an N-heterocyclic carbene (NHC) catalysis system that accesses indole and pyrrole aldehyde substrates in a desulfonylative Smiles process. The reaction proceeds under mild, transition-metal-free conditions and captures acyl anion reactivity for the synthesis of a diverse array of 2-aroyl indoles and pyrroles from readily available sulfonamide starting materials.

Synthesis and crystal structure of ethyl 4-((4-iodobenzyl)amino)benzoate, C16H16INO2

C16H16INO2, triclinic, P 1 ‾ $P\overline{1}$ (no. 2), a = 5.7004(2) Å, b = 6.8909(3) Å, c = 19.6509(8) Å, α = 100.035(4)°, β = 94.465(3)°, γ = 99.447(4)°, V = 745.27(5) Å3, Z = 2, R gt (F) = 0.0321, wR ref (F 2) = 0.0595, T = 100.15 K.

Synthesis of 1-Amino-3-oxo-2,7-naphthyridines via Smiles Rearrangement: A New Approach in the Field of Chemistry of Heterocyclic Compounds

In this paper we describe an efficient method for the synthesis of new heterocyclic systems: furo[2,3-c]-2,7-naphthyridines 6, as well as a new method for the preparation of 1,3-diamino-2,7-naphthyridines 11. For the first time, a Smiles rearrangement was carried out in the 2,7-naphthyridine series, thus gaining the opportunity to synthesize 1-amino-3-oxo-2,7-naphthyridines 4, which are the starting compounds for obtaining furo[2,3-c]-2,7-naphthyridines. The cyclization of alkoxyacetamides 9 proceeds via two different processes: the expected formation of furo[2,3-c]-2,7-naphthyridines 10 and the ‘unexpected’ formation of 1,3-diamino-2,7-naphthyridines 11 (via a Smiles type rearrangement).

Ruthenium-catalyzed reaction of diazoquinones with arylamines to synthesize diarylamines

The diarylamine scaffold is common in bioactive molecules. Herein, we report a Ru(ii)-catalyzed C–N cross-coupling reaction of diazoquinones with arylamines, which provides access to a range of functionalized diarylamines in 43–97% yields.