2978-47-4Relevant academic research and scientific papers
Di-tert-alkyl nitroxyl radicals. Synthesis, physical properties and applications as inhibitors of vinyl polmerization at elevated temperatures
Sosnovsky, George,Jawdosiuk, Mikolaj,Clumpner, J. Michael
, p. 109 - 126 (2007/10/03)
Stable di-tert-alkylnitroxyl radicals, tert-butyl-tert-pentylnitroxyl (4a), di-tert-pentylnitroxyl (4b) and tert-octyl-tert-pentylnitroxyl (4c), the homologs of di-tert-butylnitroxyl (1), were synthesized from tert-alkyl amines 7a-c via the 3-tert-alkylamino-3-methyl-1-butynes 8a-c. Oxidation of 8a,b with hydrogen peroxide lead to relatively unstable N-tert-alkyl-N-(1,1-dimethyl-prop-2-ynyl)nitroxyl radicals 15a,b. The thermal stability, vapor pressure data, ultraviolet, visible and electron paramagnetic resonance spectra of 4a-c were recorded. The radicals were explored as potential inhibitors of unwanted alkene polymerization reactions at elevated temperatures, in comparison with the aliphatic di-tert-butyl nitroxyl (1), the alicyclic nitroxyl radicals 2,2,6,6-tetramethylpiperidin-1-oxyl (2) and 4-hydroxy-2,2,6,6-tetramethyl-piperidin-1-oxyl (3), some commercial polymerization inhibitors, such as diethyl-hydroxylamine (Pennstop, 16), ammonium salt of N-hydroxy-N-nitrosobenzenamine (Cupferron, 17), bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (Tinuvin 770, 18), and the well-known spin traps 2-methyl-2-nitrosopropane (19) and tert-butylhydroxylamine (20).
Preparation of a Series of Highly Hindered Secondary Amines, Including Bis(triethylcarbinyl)amine
Kopka, Ihor E.,Fataftah, Zacharia A.,Rathke, Michael W.
, p. 4616 - 4622 (2007/10/02)
A series of highly branched secondary amines was prepared by coupling propargylamines with propargyl chlorides.Hydrogenation of the resultant dipropargylamines was accomplished with Raney nickel in the presence of potassium hydroxide.The resultant amines, including bis(triethylcarbinyl)amine, are among the most hindered secondary amines reported to date.The pKa values of the conjugate acids of the series of secondary amines exhibit a regular decrease with increasing size of the amine.The bulkier members of the series are inert to methyl iodide.Bis(triethylcarbinyl)amine reacts with boron trifluoride etherate to give a primary amine adduct and 3-ethyl-2-pentene.
