Palladium-Catalyzed One-Pot Diarylamine Formation from Nitroarenes and Cyclohexanones

Abstract

The first palladium-catalyzed diarylamine formation from nitroarenes and cyclohexanone derivatives using borrowed hydrogen is described. Various diarylamines were selectively obtained in good to excellent yields. The reaction tolerated a wide range of functionalities. The nitro reduction, cyclohexanone dehydrogenation, and imine formation and reduction were realized in a cascade without an external reducing reagent and oxidant.

Advances in One-Pot Synthesis through Borrowing Hydrogen Catalysis

“…105 Besides the traditional ruthenium and iridium complexes, other uncommon transition elements such as cobalt and osmium have been exceptionally applied in this type of reaction. 106,107 For example, it is necessary to highlight the alkylation (50a−l) of amides (49) and esters with alcohols (13) through BH methods by using the Knoevenagel reaction as intermediate reaction and cobalt complexes stabilized with pincer ligands (51). One of the most interesting features of this approach is that the Co(II) complex can be prepared on a In order to finalize this section we will refer to arylacetonitriles 107 that were also recently alkylated with primary alcohols (13) in the presence of an uncommon osmium catalyst, being included in a previous specific review on BH catalysis.…”

Pd-Catalyzed Synthesis of Aryl Amines via Oxidative Aromatization of Cyclic Ketones and Amines with Molecular Oxygen

“…Aliphatic alcohols have been arylated with 2-cyclohexen-1-ones in a Cu-catalyzed aerobic ether synthesis, 17 and aryl amines have been accessed from nitro arenes and cyclohexanones in a Pd-catalyzed cross-dehydrogenative arylation. 18 We envisaged that an aerobic aromatization of various cyclohexanone derivatives with both primary and secondary amines would introduce a direct and atom-economic access to various aryl amines. We reasoned that the transformation might be possible by following the mechanistic concept outlined in Scheme 2.…”

Condensation of Diacetyl with Alkyl Amines: Synthesis and Reactivity of p-Iminobenzoquinones and p-Diiminobenzoquinones

“…Diarylamines have become important synthetic targets as fine chemicals and precursors of a variety of N -containing pharmacological and natural products [38,39,40], such as carbazoles and ellipticines [41,42,43,44,45]. Due to the importance of diarylamines, a great number of synthetic approaches have been designed for their preparation [46,47,48]. One of the shortest and most efficient methods is through the Buchwald-Hartwig reaction, which consists of a Pd-catalyzed cross-coupling of aryl halides and anilines [49,50,51,52,53,54].…”