178100-44-2

Upstream product

• 1056456-21-3 N-methyl-N-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)acetamide 
• 122-80-5 N-acetyl-p-phenylenediamine 
• 52578-66-2 p-(acetylamino)phenyl azide 
• 74-88-4 methyl iodide 
• 119-63-1 4-(N-methylacetamido)aniline 

Downstream Products

• 3009-34-5 quinoneimine 
• 106-51-4 p-benzoquinone 

Relevant academic research and scientific papers

Kinetic stabilizing effect of the 4-N-methylacetamido substituent on the phenylnitrenium ion

Photolysis of 4-(N-methylacetamido)phenyl azide in aqueous solution results in quantitative formation of the 4-(N-methylacetamido)phenylnitrenium ion, this cation arising from solvent protonation of an initially formed singlet arylnitrene. The cation is observed by flash photolysis, and is identified through characteristic quenching by azide ion and by 2′-deoxyguanosine, both excellent nucleophiles for arylnitrenium ions in water. The nitrenium ion is protonated in acidic solutions to form the 4-(N-methylacetamido)aniline dication, whose pKa is determined to be 1.5 based on the rate-pH profile. This means that the nitrenium ion is relatively basic, which suggests that there is significant positive charge on the N-methylacetamido group. Further evidence for this is seen in the remarkably long lifetime (5 ms) of the nitrenium ion in water. In fact, the 4-(N-methylacetamido)phenylnitrenium ion is 5000-fold longer-lived than the 4-methoxy-substituted analog. A 4-methoxy substituent on a phenyl ring is more electron donating according to σ+ values (-0.78 for MeO vs. -0.60 for NMeAc). The dramatic reversal in the arylnitrenium ions is another example of the failure of these to follow the carbocation scale.

Catalytic Azoarene Synthesis from Aryl Azides Enabled by a Dinuclear Ni Complex

Azoarenes are valuable chromophores that have been extensively incorporated as photoswitchable elements in molecular machines and biologically active compounds. Here, we report a catalytic nitrene dimerization reaction that provides access to structurally and electronically diverse azoarenes. The reaction utilizes aryl azides as nitrene precursors and generates only gaseous N2 as a byproduct. By circumventing the use of a stoichiometric redox reagent, a broad range of organic functional groups are tolerated, and common byproducts of current methods are avoided. A catalyst featuring a Ni - Ni bond is found to be uniquely effective relative to those containing only a single Ni center. The mechanistic origins of this nuclearity effect are described.

Thermolysis and radiofluorination of diaryliodonium salts derived from anilines

Aniline-derived diaryliodonium salts were synthesized and functionalized in good to excellent yields by judicious utilization of electron-withdrawing protecting groups. This simple approach opens another route to radiolabeling amino arenes in relatively complex molecules, such as flutemetamol.

Chemical Consequences of Arylnitrenes in the Crystalline Environment

UV photolysis of powdered crystals of several aryl azides at cryogenic temperatures afforded azo compounds predominantly. In the cases of p-(N-methylacetamido)phenyl azide and 2-azidobiphenyl, a CH insertion product or a carbazole was formed, competing with azo formation. These products can be considered to be formed through topotactic processes when the crystal structures are taken into account. The arylnitrenes generated in the azide crystals were monitored by ESR spectroscopy; they turned out to have extremely long half life-times, compared with those in the gas phase or in solution. Such high kinetic stabilities are ascribed to the inert environment around the generated nitrenes. The decay process of arylnitrenes in the initial stage obeyed a pseudo-first order kinetics; activation parameters were evaluated by Arrhenius plots. The activation enthalpies and entropies indicate that the diffusional processes of arylnitrenes may be the vital factors determining the kinetic stability and the product distribution in the crystalline environment.