- Controllable selective functionalization of a cavitand via solid state photolysis of an encapsulated phenyl azide
-
Phenyl azide (1) has been encapsulated within cavitand 2 to form a 1:1 complex of 1@2 in the solid state. Subsequent irradiation affords two diastereomeric nitrene addition products 5 and 7. The ratio of 5 and 7 can be reversed by thermally induced valence isomerization to 1Hazepine 8 followed by photolysis. In sharp contrast, phenylnitrene generation by photolysis of the corresponding 1.5:1 complex results mainly in the regioselective formation of C-H insertion product 4. The supramolecular approach to phenylnitrene chemistry provides good yields, in contrast to the generally low yield reactions of this species in solution.
- Wagner, Gerald,Arion, Vladimir B.,Brecker, Lothar,Krantz, Carsten,Mieusset, Jean-Luc,Brinker, Udo H.
-
supporting information; experimental part
p. 3056 - 3058
(2009/12/22)
-
- Process for preparing aromatic azo and hydrazo compounds, aromatic amides and aromatic amines
-
A process for producing amino or amido substituted aromatic azo or hydrazo compounds, or aminoaromatic amines, or aminoaromatic amides, or mixtures thereof, comprises the steps of: (a) bringing into reactive contact in a suitable solvent system a nucleophilic compound selected from the group of aniline, substituted aniline derivatives, aliphatic amines, substituted aliphatic amine derivatives, amides and substituted amide derivatives with an azo containing compound; and (b) reacting the nucleophilic compound and the azo containing compound in a confined zone at a suitable time, pressure and temperature.
- -
-
-
- Method of preparation of 4-aminodiphenylamine
-
A method of preparing 4-aminodiphylamine through an intermediate preparation of 4-nitrodiphenylamine and/or 4-nitrosodiphenylamine and/or their salts by reaction of aniline with nitobenzene in a liquid medium at a temperature of 50 to 130° C., under normal or reduced pressure, in an inert atmosphere or in the presence of air oxygen, with subsequent hydrogenation of an intermediate of 4-nitrodiphenylamine and/or nitrosodiphenylamine and side products, and by isolation of 4-aminodiphenylamine and the side products of unconverted raw materials.
- -
-
Page column 7
(2008/06/13)
-
- Electronic spectra of push-pull 4-phenylaminoazobenzene derivatives
-
A series of push-pull type 4-phenylaminoazobenzene derivatives bearing an electron-withdrawing 4'-substituent were probed by electronic spectra in solution. The visible absorption maxima of these azobenzenes were correlated with the solvent parameters through the McRae theory as well as the solvent donor numbers. While the absorption spectra of these neutral species were solvent-dependent, those of protonated species were almost solvent independent. On the other hand, the absorption maxima and the rates of thermal cis-to-trans isomerization in a given solvent were correlated with Hammett constants. These results are discussed with the help of semi- empirical molecular-orbital calculations and compared with previously published data on related compounds.
- Makita, Shohei,Saito, Ayako,Hayashi, Makoto,Yamada, Shohei,Yoda, Koji,Otsuki, Joe,Takido, Toshio,Seno, Manabu
-
p. 1525 - 1533
(2007/10/03)
-
- A New Route to 4-Aminodiphenylamine via Nucleophilic Aromatic Substitution for Hydrogen: Reaction of Aniline and Azobenzene
-
A new example of nucleophilic aromatic substitution for hydrogen is described which encompasses reacting aniline and azobenzene (1) in the presence of base under aerobic conditions to generate 4-(phenylazo)diphenylamine (2) in high yield.Monitoring the time course of the reaction under anaerobic conditions revealed that hydrazobenzene (9) was formed as an intermediate in the reaction in equal molar amounts as 2.However, under aerobic conditions 9 was shown not to persist in the reaction mixture.The kinetic effect of isotopic substitution on this reaction was probed by competition experiments utilizing equal molar mixtures azobenzene-d10 and undeuterated material which gave a kH/kD of 4.6 +/- 0.1.It was concluded from these studies that azobenzene was functioning as both the electrophile and oxidant in this reaction.Catalytic hydrogenation of 2 generates 4-aminodiphenylamine (4-ADPA) (10) and aniline.These reactions form the basis of a novel synthetic route to 4-ADPA which does not utilize halogenated intermediates or reagents and ultimately relies on O2 as the terminal oxidant in the system.
- Stern, Michael K.,Cheng, Brian K.,Hileman, Frederick D.,Allman, James M.
-
p. 5627 - 5632
(2007/10/02)
-
- Superoxide-Promoted Oxidation Reactions of Aniline and N-Methylaniline in Dimethyl Sulfoxide
-
The chemistry of superoxide was investigated in reference to its reactions with primary and secondary aromatic amines.Two aromatic amines (aniline and N-methylaniline) reacted extensively in aprotic solutions containing potassium superoxide.In the case of aniline, trans-azobenzene and 4-nitrodiphenylamine were the major products, with smaller amounts of 4-aminodiphenylamine, 4-nitrosodiphenylamine, and p-(phenylazo)diphenylamine also being produced.With N-methylaniline, both oxidation and demethylation occurred, leading to the isolation of N-phenylformamide, aniline,and smaller amounts of azobenzene and 4-nitrodiphenylamine.Both superoxide and hydrogen peroxide alone were unable to convert either 4-aminodiphenylamine to its nitro and nitroso derivatives or N-phenylformamide to aniline.Solutions containing potassium tert-butoxide in place of superoxide produced the same products and oxygen was required for the reaction.Taken together, these results indicated that primary and secondary reducing aromatic amines are readily ionized by superoxide in aprotic solutions and then oxidized in a process involving molecular oxygen, leading to products whose structures suggest that processes such as radical recombination, N-oxidation, and N-demethylation have taken place.
- Stuehr, Dennis J.,Marletta, Michael A.
-
p. 694 - 696
(2007/10/02)
-
- THERMAL AND PHOTOCHEMICAL DECOMPOSITION OF 3- AND 4-AZIDOPYRIDINE 1-OXIDES IN NUCLEOPHILIC SOLVENTS
-
The thermolysis and photolysis of the title compounds in aniline, N-methylaniline, N,N-dimethylaniline, morpholine and dioxane containing methoxide ion in methanol afforded complex mixtures from which only major products were isolated.No ring-expansion products were detected.In aniline, many of its known oxidation products were found, the N-oxide acting as an oxidizing agent.Hydrogen-abstraction products were the main ones formed from pyridine 1-oxides.
- Abramovitch, Rudolph A.,Bachowska, Barbara,Tomasik, Piotr
-
p. 805 - 815
(2007/10/02)
-