New Method for Preparation of Isolable N-tert-Alkoxyarylaminyl Radicals

Abstract

Stable N-tert-alkoxy-2,4-diphenyl-6-tert-butylphenylaminyl radicals were prepared by heating 2,4-diphenyl-6-tert-butylphenylnitrosobenzenes and azo compounds in refluxing benzene and isolated as radical crystals. Their structures were confirmed by the elemental analyses, ESR, and X-ray crystallography.

Radical Single-Molecule Junctions

“…Oxoaminyl radicals, which have the structure RNOR • ( 6c ), are persistent but not isolable. Those that have been isolated require stable aromatic groups bound to the nitrogen group ( 6d ). − Additionally, certain nitroxide groups, namely TEMPO, are stable enough to be synthesized, isolated, and measured in single-molecule junctions, which will be discussed later in this Perspective. There are also nitrogen-based radical cations that can be made using chemical oxidants, which have also been measured in single-molecule junctions and will be discussed further.…”

Electrochemical study of stable N-alkoxyarylaminyl radicals

“…High resolution FAB mass spectra (HRFABMS) were recorded with a JEOL JMS-7000T mass spectrometer. (2) and N-tert-butoxy-2,4,6-tris(4-chlorophenyl)phenylaminyl (3) were prepared by our previously reported methods [12,16,17]. N-[(4-Nitrophenyl)thio]-2,4-bis(4-chlorophenyl)-6-tert-butylphenylaminyl (9) was prepared according to our previously reported method [21].…”

“…Although N-alkoxyaminyl radicals were extensively studied by ESR spectroscopy over a long time [1][2][3][4][5][6][7][8][9][10], the first isolation of N-alkoxyaminyls by our group was quite recent [11][12][13][14][15][16][17]. We obtained isolable N-alkoxyarylaminyls by two methods.…”

“…We obtained isolable N-alkoxyarylaminyls by two methods. One method involves the reaction of the lithium salts of 2,4,6-tri-substituted anilines with tert-alkyl peroxybenzoates [11][12][13][14][15] and the other involves the reaction of 2,4-diaryl-6-tert-butylnitrosobenzenes with azo compounds [16,17]. Interestingly, the isolated N-alkoxyarylaminyls are stable in the presence of oxygen even in solution and, although they were heated at 80 • C in benzene for 10 days, 80% of the radical survived.…”

New Method for the Synthesis of N-tert-Alkoxyarylaminyl Radicals1

“…For example, the isolated radical yields are low, ,− (12−27%) and the use of butyllithium in the radical syntheses refuses the presence of functional groups. To overcome these problems, much effort has been paid, and we have now established a new convenient method for the synthesis of N - tert -alkoxyarylaminyls . The method involves the addition of a tert -alkyl radical to 2,4-diaryl-6- tert -butylnitrosobenzenes.…”