3586-00-3

Usage

Chemical compound

1,4-Benzenediamine, N,N-dimethyl-N'-phenyl-

Usage

Popular ingredient in hair dyes and black henna tattoos

Purpose

Produces a dark color in hair dyes and tattoos

Health risks

Associated with allergic reactions and skin sensitization

Severe effects

Can cause severe dermatitis in some individuals

Long-term exposure risks

Linked to respiratory issues and potential carcinogenic effects

Regulatory status

Restrictions placed on the use of PPD in certain products by regulatory agencies in several countries due to potential health risks

Upstream product

• 60-29-7 diethyl ether 
• 871876-73-2 2,3-dimethyl-4-nitroso-aniline 
• 100-63-0 phenylhydrazine 
• 100-23-2 N,N-Dimethyl-4-nitroaniline 
• 586-77-6 4-bromo-N,N-dimethylaniline 
• 62-53-3 aniline 
• 64-17-5 ethanol 
• 138-89-6 p-dimethylaminonitrosobenzene 
• 100-59-4 phenylmagnesium chloride 
• 108-86-1 bromobenzene 
• 99-98-9 4-amino-N,N-dimethylaniline 
• 109-72-8 n-butyllithium 
• 98-95-3 nitrobenzene 
• 591-50-4 iodobenzene 

Downstream Products

• 4316-50-1 N,N-dimethyl-N',N'-diphenyl-1,4-phenylenediamine 
• 330792-75-1 4-(hexyloxy)-N-(4-(hexyloxy)phenyl)-N-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)aniline 

Relevant academic research and scientific papers

Enolizable Ketones as Activators of Palladium(II) Precatalysts in Amine Arylation Reactions

Enolizable ketones have been identified as effective activators for palladium(II) precatalysts in the coupling of aryl bromides and aniline. N-arylation reactions catalyzed by [(DTBNpP)PdCl2]2 (DTBNpP = (bis(tert-butyl)neopentylphosphine) and PEPPSI-IPr precatalysts are activated by the addition of acetone, mesityl oxide, and 3-pentanone. 3-Pentanone was the most effective activator. Mechanistic studies show that acetone, 3-pentanone, and mesityl oxide reduce [(DTBNpP)PdCl2]2 in the presence of NaO-t-Bu to Pd0(DTBNpP)2

A Polystyrene-Cross-Linking Tricyclohexylphosphine: Synthesis, Characterization and Applications to Pd-Catalyzed Cross-Coupling Reactions of Aryl Chlorides

A polystyrene-cross-linking tricyclohexylphosphine (PS-TCP) was synthesized through radical emulsion polymerization of 4-tert-butylstyrene as a monomer and tris(trans-4-styrylcyclohexyl)phosphine as a threefold cross-linker. The PS-TCP showed enhanced ligand performance compared to the corresponding polystyrene-triphenylphosphine hybrid PS-TPP and tricyclohexylphosphine in Pd-catalyzed Suzuki–Miyaura and Buchwald–Hartwig reactions of aryl chlorides.

Versatile routes for synthesis of diarylamines through acceptorless dehydrogenative aromatization catalysis over supported gold-palladium bimetallic nanoparticles

Diarylamines are an important class of widely utilized chemicals, and development of diverse procedures for their synthesis is of great importance. Herein, we have successfully developed novel versatile catalytic procedures for the synthesis of diarylamines through acceptorless dehydrogenative aromatization. In the presence of a gold-palladium alloy nanoparticle catalyst (Au-Pd/TiO2), various symmetrically substituted diarylamines could be synthesized starting from cyclohexylamines. The observed catalysis of Au-Pd/TiO2 was heterogeneous in nature and Au-Pd/TiO2 could be reused several times without severe loss of catalytic performance. This transformation needs no oxidants and generates molecular hydrogen (three equivalents with respect to cyclohexylamines) and ammonia as the side products. These features highlight the environmentally benign nature of the present transformation. Furthermore, in the presence of Au-Pd/TiO2, various kinds of structurally diverse unsymmetrically substituted diarylamines could successfully be synthesized starting from various combinations of substrates such as (i) anilines and cyclohexanones, (ii) cyclohexylamines and cyclohexanones, and (iii) nitrobenzenes and cyclohexanols. The role of the catalyst and the reaction pathways were investigated in detail for the transformation of cyclohexylamines. The catalytic performance was strongly influenced by the nature of the catalyst. In the presence of a supported gold nanoparticle catalyst (Au/TiO2), the desired diarylamines were hardly produced. Although a supported palladium nanoparticle catalyst (Pd/TiO2) gave the desired diarylamines, the catalytic activity was inferior to that of Au-Pd/TiO2. Moreover, the activity of Au-Pd/TiO2 was superior to that of a physical mixture of Au/TiO2 and Pd/TiO2. The present Au-Pd/TiO2-catalyzed transformation of cyclohexylamines proceeds through complex pathways comprising amine dehydrogenation, imine disproportionation, and condensation reactions. The amine dehydrogenation and imine disproportionation reactions are effectively promoted by palladium (not by gold), and the intrinsic catalytic performance of palladium is significantly improved by alloying with gold. One possible explanation of the alloying effect is the formation of electron-poor palladium species that can effectively promote the β-H elimination step in the rate-limiting amine dehydrogenation.

SUBSTITUTED DIARYLAMINES AND USE OF SAME AS ANTIOXIDANTS

The present invention relates to substituted heteroaromatic dianlamine compounds of Formula I and II, their pharmaceutically acceptable salts, and compositions thereof useful as antioxidants, wherein each of X, Y and Z are independently a carbon or nitrogen atom; R1 and R2 are each independently a hydrogen or an electron donating group, but are not both hydrogen, and wherein R1 and R2 are each bonded to a carbon atom in their own respective aryl ring.

Amination of aryl iodides catalyzed by a palladium-copper complex supported by a chelate-bridging ligand

Palladium-copper complexes supported by a new chelate-bridging ligand designed for a cooperative effect of two metals were synthesized. The bimetallic complexes exhibited higher activities as catalysts for amination of aryl iodides than mononuclear catalyst.

Synthesis and X-ray structure determination of highly active Pd(II), Pd(I), and Pd(0) complexes of Di(tert -butyl)neopentylphosphine (DTBNpP) in the arylation of amines and ketones

The air-stable complex Pd(eta;3-allyl)(DTBNpP)Cl (DTBNpP = di(tert-butyl)neopentylphosphine) serves as a highly efficient precatalyst for the arylation of amines and enolates using aryl bromides and chlorides under mild conditions with yields ranging from 74% to 98%. Amination reactions of aryl bromides were carried out using 1-2 mol % Pd(η3-allyl)(DTBNpP)Cl at 23-50 °C without the need to exclude oxygen or moisture. The C-N coupling of the aryl chlorides occurred at relatively lower temperature (80-100 °C) and catalyst loading (1 mol %) using the Pd(eta;3-allyl) (DTBNpP)Cl precatalyst than the catalyst generated in situ from DTBNpP and Pd2(dba)3 (100-140 °C, 2-5 mol % Pd). Other Pd(DTBNpP)2-based complexes, (Pd(DTBNpP)2 and Pd(DTBNpP)2Cl2) were ineffective precatalysts under identical conditions for the amination reactions. Both Pd(DTBNpP)2 and Pd(DTBNpP)2Cl2 precatalysts gave nearly quantitative conversions to the product in the α-arylation of propiophenone with p-chlorotoluene and p-bromoanisole at a substrate/catalyst loading of 100/1. At lower substrate/ca'alyst loading (1000/1), the conversions were lower but comparable to that of Pd(t-Bu3P)2. In many cases, the tri-tert-butylphosphine (TTBP) based Pd(I) dimer, [Pd(μ-Br)(TTBP)] 2, stood out to be the most reactive catalyst under identical conditions for the enolate arylation. Interestingly, the air-stable Pd(I) dimer, Pd2(DTBNpP)2(μ-Cl)(μ-allyl), was less active in comparison to [Pd(μ-Br)(TTBP)]2 and Pd(eta;3-allyl) (DTBNpP)Cl. The X-ray crystal structures of Pd(eta;3-allyl)(DTBNpP) Cl, Pd(DTBNpP)2Cl2, Pd(DTBNpP)2, and Pd 2(DTBNpP)2(μ-Cl)(μ-allyl) are reported in this paper along with initial studies on the catalyst activation of the Pd(eta;3-allyl)(DTBNpP)Cl precatalyst.

Neopentylphosphines as effective ligands in palladium-catalyzed cross-couplings of aryl bromides and chlorides

The use of neopentylphosphine ligands in the palladium-catalyzed Suzuki, Sonogashira, Heck, and Hartwig-Buchwald couplings of aryl bromides and chlorides are reported. Di-tert-butylneopentylphosphine (DTBNpP) provided highly active catalysts for the coupling of aryl bromides at mild temperatures. Trineopentylphosphine, an air-stable trialkylphosphine, gave inactive catalysts at room temperature, but showed good activity in the H-B amination of aryl chlorides at elevated temperatures.

Bulky alkylphosphines with neopentyl substituents as ligands in the amination of aryl bromides and chlorides

Di(tert-butyl)neopentylphosphine (DTBNpP) in combination with palladium sources provided catalysts with comparable or better activity for the Hartwig-Buchwald amination of aryl bromides than tri(tert-butyl)phosphine (TTBP) under mild conditions. DTBNpP also provided effective catalysts for amination reactions of aryl chlorides at elevated temperatures. Further replacement of tert-butyl groups with neopentyl substituents resulted in less effective ligands for amination reactions. Computationally derived cone angles showed that replacement of a tert-butyl group with a neopentyl group significantly increased the cone angle of the phosphine. The larger cone angle of DTBNpP than TTBP appears to correlate with the higher activity of catalysts derived from DTBNpP in the amination of aryl bromides. TTBP is a stronger electron donor than DTBNpP, which may explain the higher activity for TTBP-derived catalysts toward aryl chlorides.

Effect of steric and electronic properties of palladium complexes with bidentate diphosphine ligands on the basis of diphenyl oxide on arylation of amines

New complexes of palladium chloride with bidentate diphosphine ligands on the basis of 2,2′-bis(diorganylphosphino)diphenyl oxides were prepared by three methods, and their catalytic activity in arylation of amines was studied. 2005 Pleiades Publishing, Inc.

Preparation of diarylamines by the addition of 4-(N,N-dimethylamino)phenyllithium to nitroarenes

The addition of 4-(N,N-dimethylamino)phenyllithium to nitroarenes in THF (-78°C) affords the corresponding diarylamines in one-pot and the reaction appears to be general in scope. A 'nitroso'-based mechanism is proposed for this novel nitroreductive N-arylation reaction.