Reductive Amination of Aryl Boronic Acids: Parallelism of the Catalytic Reactivity of Transition Metals and Main Group Elements in the C(sp2)–N Bond-Forming Reactions

The results of the DFT studies on the mechanism of the PIII/PV=O catalyzed reductive amination of nitrosoarenes using ArB(OH)2 yielding diaryl amines are reported. This allowed a comparison of the reaction paths and key intermediates of the Cu(I)- and P(III)-mediated reductive aminations of aryl boronic acids using alkylnitrites, nitroso- or nitroarenes, and revealed important similarities in the catalytic reactivity of transition-metal and main-group elements in C(sp2)–N bond-forming reactions. It is shown that both transformations occur via ambiphilic nitrenoid-type key intermediates, the reactivity of which towards the aryl boronic acid is attributed to the presence of both a Lewis acid center (Cu or P) and a Lewis base center (the N or O atoms of the ‘N=O’ component).

Synthesis of blue-red emissive amido-substituted di(het)aryl and tri(het)aryl amine derivatives via chemoselective N-mono and N,N-diarylation of (het) aryl amino amides using benzyne/arynes

Chemoselective synthesis of amide-substituted triaryl and diaryl amines by N-mono and N,N-diarylation of (het)aryl amino amides using arynes has been reported. Selected triarylamines showed blue-red emission.

Electrochemical/Photochemical Aminations Based on Oxidative Cross-Coupling between C–H and N–H

The construction of nitrogen-containing molecules remains at the cutting edge of organic synthesis because of its wide application in various areas. Instead of prefunctionalized substrates, using free C–H and N–H bonds in the starting materials can supply a more sustainable avenue to the C–N bond-forming reactions. Compared with the well-developed transition-metal-catalyzed protocols, the strategy of introducing optical or electrical energy into reactions is fantastic and appealing. As a result, visible light or electricity mediated amination transformations have continued to develop over the past several years. In this short review, recent progress of carbon–nitrogen bond-forming reactions based on the oxidative cross coupling between C(sp2, sp3)–H and N–H are summarized.1 Introduction2 C(sp2)–H/N–H Oxidative Cross Coupling2.1 Aryl C(sp2)–H as C Nucleophiles2.1.1 Azoles as N Nucleophiles2.1.2 Sulfonamides or Sulfonimides as N Nucleophiles2.1.3 NH3 as N Nucleophile2.1.4 Morpholine as N Nucleophile2.1.5 Diaryl Amines as N Nucleophiles2.1.6 Primary Amines as N Nucleophiles2.1.7 Imides as N Nucleophiles2.1.8 Imines as N Nucleophiles2.2 Alkenyl C(sp2)–H as C Nucleophiles2.3 Aldehydic C(sp2)–H as C Nucleophiles3 C(sp3)–H/N–H Oxidative Cross Coupling3.1 Benzylic C(sp3)–H as C Nucleophiles3.2 α-C(sp3)–H as C Nucleophiles4 Conclusions and Outlook

Synthesis and anion recognition properties of shape-persistent binaphthyl-containing chiral macrocyclic amides

We report on the synthesis and characterization of novel shape-persistent, optically active arylamide macrocycles, which can be obtained using a one-pot methodology. Resolved, axially chiral binol scaffolds, which incorporate either methoxy or acetoxy functionalities in the 2,2' positions and carboxylic functionalities in the external 3,3' positions, were used as the source of chirality. Two of these binaphthyls are joined through amidation reactions using rigid diaryl amines of differing shapes, to give homochiral tetraamidic macrocycles. The recognition properties of these supramolecular receptors have been analyzed, and the results indicate a modulation of binding affinities towards dicarboxylate anions, with a drastic change of binding mode depending on the steric and electronic features of the functional groups in the 2,2' positions.