136708-39-9

Upstream product

• 40908-37-0 N-(2,2,6,6-tetramethylpiperidin-4-yl)acetamide 
• 136708-42-4 4-(acetylamino)-2,2,6,6-tetramethyl-1-hydroxy-piperidinium p-toluenesulfonate 
• 136708-43-5 4-acetylamino-2,2,6,6-tetramethyl-1-piperidinium acetate 
• 14691-88-4 4-amino-2,2,6,6-tetramethyl-1-piperidine-1-oxyl 
• 64-19-7 acetic acid 
• 36768-62-4 4-AMINO-2,2,6,6-TETRAMETHYLPIPERIDINE 
• 1620751-78-1 N-[2,2,6,6-tetramethyl-1-(2-nitrobenzyloxy)piperidin-4-yl]acetamide 
• 826-36-8 2,2,6,6-Tetramethyl-4-piperidone 
• 4168-79-0 4-hydroxyimino-2,2,6,6-tetramethylpiperidine 
• 110-89-4 piperidine 
• 201415-38-5 5-phenylbenzoxazole 

Downstream Products

• 36410-81-8 4-isothiocyanato-2,2,6,6-tetramethylpiperidine N-oxide 
• 122586-91-8 N-(1-Cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)acetamide 
• 1350920-13-6 4-acetamido-2,2,6,6-tetramethylpiperidine-N-hydroxyammonium tetrafluoroborate 
• 14691-88-4 4-amino-2,2,6,6-tetramethyl-1-piperidine-1-oxyl 
• 14691-88-4 4-amino-2,2,6,6-tetramethylpiperidinyloxy 

Relevant academic research and scientific papers

Preparation of Some Homologous TEMPO Nitroxides and Oxoammonium Salts; Notes on the NMR Spectroscopy of Nitroxide Free Radicals; Observed Radical Nature of Oxoammonium Salt Solutions Containing Trace Amounts of Corresponding Nitroxides in an Equilibrium Relationship

Three new homologous TEMPO oxoammonium salts and three homologous nitroxide radicals have been prepared and characterized. The oxidation properties of the salts have been explored. The direct 13C NMR and EPR spectra of the nitroxide free radicals and the oxoammonium salts, along with TEMPO and its oxoammonium salt, have been successfully measured with little peak broadening of the NMR signals. In the spectra of all ten compounds (nitroxides and corresponding oxoammonium salts), the carbons in the 2,2,6,6-tetramethylpiperidine core do not appear, implying paramagnetic properties. This unpredicted overall paramagnetism in the oxoammonium salt solutions is explained by a redox equilibrium as shown between oxoammonium salts and trace amounts of corresponding nitroxide. This equilibrium is confirmed by electron interchange reactions between nitroxides with an N-acetyl substituent and oxoammonium salts with longer acyl side chains.

Reaction of Nitroxides with Sulfur Containing Compounds II [1]. Preparation of Nitroxides Bearing an Isothiocyanate Substituent in View of the Nitroxyl Group Reduction with Thiophosgene

The reaction of thiophosgene with 2,2,6,6-tetramethylpiperidine-1-oxyl (used as a model nitroxyl radical) was examined. 2,2,6,6-Tetramethylpiperidine and 2,2,6,6-tetramethyl-1-hydroxypiperidine were identified as products. The reaction is not competitive with the reaction of thiophosgene with an amino group. Thus, three nitroxides with an isothiocyanate group were synthesized from thiophosgene and the nitroxides containing the amino substituent.

A revised preparation of (4-Acetamido-2,2,6,6-tetramethylpiperidin-1-yl) oxyl and 4-acetamido-2,2,6,6-tetramethyl-1-oxopiperidinium tetrafluoroborate: Reagents for stoichiometric oxidations of alcohols

Revised preparations of (4-acetamido-2,2,6,6-tetramethylpiperidin-1-yl)oxyl and the corresponding oxoammonium salt, 4-acetamido-2,2,6,6-tetramethyl-1- oxoammonium tetrafluoroborate are presented together with some of the important properties of these two oxidizing reagents. Georg Thieme Verlag Stuttgart New York.

Synthesis and fluorescence properties of six fluorescein-nitroxide radical hybrid-compounds

Six fluorescein-nitroxide radical hybrid-compounds (2ab, 3ab, 4, and 5) were synthesized by the condensation of 5- or 6-carboxy-fluorescein and 4-amino-TEMPO (2ab), 5- or 6-aminofluorescein and 4-carboxy-TEMPO (3ab), and fluorescein and 4-carboxy-TEMPO (4), or by reaction of the 3-hydroxyl group of fluorescein with DPROXYL-3-ylmethyl methanesulfonate (5). Fluorescence intensities (around 520 nm) after reduction of the radical increased to 1.43-, 1.38-, and 1.61-folds for 2a, 2b and 3b respectively; 3a alone exhibited a decrease in intensity on reduction. Since 4 was readily solvolyzed in PBS or even methanol to afford fluorescein and 4-carboxy-TEMPO, its fluorescence change could not be measured. Hybrid compound 5 containing an ether-linkage between the fluorescein phenol and 3-hydroxymethyl-DPROXYL hydroxyl centers, was stable and on reduction, showed a maximum increase (3.21-fold) in relative fluorescence intensity in PBS (pH 5.0), despite its remarkably low absolute fluorescence intensity.

Selective Aromatic C-H Hydroxylation Enabled by η6-Coordination to Iridium(III)

We report an aromatic C-H hydroxylation protocol in which the arene is activated through η6-coordination to an iridium(III) complex. η6-Coordination of the arene increases its electrophilicity and allows for high positional selectivity of hydroxylation at the site of least electron density. Through investigation of intermediate η5-cyclohexadienyl adducts and arene exchange reactions, we evaluate incorporation of arene π-activation into a catalytic cycle for C-H functionalization.

Kinetics and thermodynamics of reversible disproportionation-comproportionation in redox triad oxoammonium cations - Nitroxyl radicals - Hydroxylamines

Kinetics and equilibrium of the acid-catalyzed disproportionation of cyclic nitroxyl radicals R2NO· to oxoammonium cations R2NO+ and hydroxylamines R2NOH is defined by redox and acid-base properties of these compounds. In a recent work (J. Phys. Org. Chem. 2014, 27, 114-120), we showed that the kinetic stability of R2NO· in acidic media depends on the basicity of the nitroxyl group. Here, we examined the kinetics of the reverse comproportionation reaction of R2NO+ and R2NOH to R2NO· and found that increasing in -I-effects of substituents greatly reduces the overall equilibrium constant of the reaction K4. This occurs because of both the increase of acidity constants of hydroxyammonium cations K3H+ and the difference between the reduction potentials of oxoammonium cations ER2NO+/R2NO· and nitroxyl radicals ER2NO·/R2NOH. pH dependences of reduction potentials of nitroxyl radicals to hydroxylamines E1/3σ and bond dissociation energies D(O-H) for hydroxylamines R2NOH inwater were determined. For a wide variety of piperidine- and pyrrolidine-1-oxyls values of pK3H+ and ER2NO+/R2NO· correlate with each other, as well aswith the equilibriumconstants K4 and the inductive substituent constants ωI. The correlations obtained allowprediction of the acid-base and redox characteristics of redox triads R2NO·-R2NO+-R2NOH.

Photolabile protecting groups for nitroxide spin labels

Nitroxide spin labels can be protected against critical conditions of DNA/RNA or peptide synthesis by reduction and alkylation with light-sensitive groups such as nitrobenzyl- or aminocoumarins. High chemical stability qualifies tetraethylisoindoline 5 an

Amination of benzoxazoles and 1,3,4-oxadiazoles using 2,2,6,6- tetramethylpiperidine-N-oxoammonium tetrafluoroborate as an organic oxidant

No transition metals are necessary to convert benzoxazoles and 1,3,4-oxadiazoles into the corresponding pharmacologically interesting 2-aminated heterocycles by formal direct C(2)-amination using tetramethylpiperidine-N-oxoammonium tetrafluoroborate (TEMPO+BF 4-) as an oxidant (see scheme; TEMP=2,2,6,6- tetramethylpiperidine; TfOH=trifluoromethanesulfonic acid).

Oxidation of primary and secondary alcohols by 4-acetylamino-2,2,6,6- tetramethylpiperidine-1-oxoammonium tetrafluoroborate in aqueous media

water soluble oxidant 4-acetylamino-2,2,6,6-tetramethylpiperidine-1- oxoammonium tetrafluoroborate 1 oxidizes primary and secondary aliphatic, primary allylic, and primary and secondary benzylic alcohols to their corresponding aldehydes and ketones in aqueous media in good to excellent yields. ARKAT-USA, Inc.

Synthesis of 2,2,6,6-tetramethylpiperidine derivatives

Diazotization of 4-amino-2,2,6,6-tetramethylpiperidine in acetic or sulfuric acid affords 2,2,6,6-tetramethyl-1,2,3,6-tetrahydropyridine in high yield. Under the same conditions, the corresponding nitroxyl radical transforms into 4-hydroxy-2,2,6,6-tetrame