Divalent Nitrogen. I. The Rate of Dissociation of Tetraphenylhydrazine¹

Abstract

Rate of Dissociation of Tetraphenylhydrazine 1163The ether solution was treated with Ñorit and the product crystallized from ether to give a product with m. p. 200-205°, dec.; yield 4.2 g.

Cu-Catalyzed Aerobic Oxidative N–N Coupling of Carbazoles and Diarylamines Including Selective Cross-Coupling

“…Control experiments reveal that N–N cleavage in 2p is not promoted by copper and that N–N bond formation in 3a is irreversible under the reaction conditions (Figure S6). The N–N bond in tetraarylhydrazines is quite weak (e.g., BDE = 23.5 kcal/mol for ph 2 N–NPh 2 20 ), and homolytic cleavage of the tetraarylhydrazine N–N bond will generate aminyl radicals 21 capable of undergoing cross-coupling with the carbazole coupling partner. Irrespective of mechanism, the observations show that preferential formation of the cross-coupled product 3a over 2p is thermodyanamically controlled.…”

Acid catalysis of the radical decomposition of tetraphenylhydrazine

“…The radical decomposition of tetraphenylhydrazine was studied previously. 2,[5][6][7][8][9] The course of the reaction was monitored by spectrophotometry. N,N'-Diphenyl-1,4-phenylenediamine is converted into intensely coloured quinonediimine Ph-N=C 6 H 4 =N-Ph (QDI) in the reactions with free radicals where QDIH• is the 4-anilinodiphenylaminyl semiquinone radical Ph-N • -C 6 H 4 -NH-Ph, which is formed from DPPDA.…”

Transition‐Metal‐Free Dehydrogenative N–N Coupling of Secondary Amines with KI/KIO4

“…The origin of the cross‐coupling outcome might be the quite weak N–N bond of tetraphenylhydrazines (e.g., BDE = 23.5 kcal/mol for Ph 2 N–NPh 2 ). [6e], The dimerization of bis(4‐bromophenyl)amine should be reversible, which eventually shifts the equilibrium to the more stable cross‐coupled products. The above hypothesis was supported well by the experiment shown in Schemeà.…”