Synthesis and structure of N-alkoxyhydrazines and N-alkoxy-N’,N’,N’-trialkylhydrazinium salts

Abstract

Mendeleev Communications N-Alkoxyhydrazines represent an interesting example of ON -N geminal systems. 1-10 Usually, N-alkoxyhydrazines are very unstable due to n N ® s* N-O(Alk) orbital interaction within the N-OAlk bond. 11 Only one compound of this type 1 is known, 11 in which the donor capacity of nitrogen is decreased owing to its participation in aziridine cycle (Scheme 1). Tetramethoxyhydrazine 2 3 easily dissociates into two dimethoxyaminyl radicals on heating since its N-N bond is weakened by n O(Me) ® s* N-N anomeric effect. 3,4 The other N-alkoxy-N-alkylhydrazines are postulated as unstable primary intermediates in nucleophilic substitution at nitrogen atom in the reactions of N-chloro-N-alkoxy-N-tert-alkylamines with N-nucleo philes 9,11 and in the reactions of N-acyloxy-N-alkoxybenzamides with anilines. 12,13 However, N-alkoxyhydrazines with electron-withdrawing substituents at both nitrogen atoms, such as N,N'-dialkoxy-N,N'-bis-(alkoxycarbonyl)hydrazines 14 and N,N'-diacyl-N,N'-dialkoxyhydrazines 8,15,16 are relatively stable compounds. Among them, structure of N,N'-bis(4-chlorobenzoyl)-N,N'-diethoxyhydrazine 3 has been studied by XRD. 8 For the further XRD studies of N-alkoxyhydrazines structures we selected N,N'-bis(methoxycarbonyl)-N,N'-dimethoxyhydrazine 5 and N-methoxyhydrazine 7. Compound 5 is major product of methanolysis of methyl N-chloro-N-methoxycarbamate 4 in the presence of Et 3 N. 17 Compound 7 was synthesized by the reaction of compound 4 with potassium salt of N-acetylbenzenesulfonamide in MeCN (see Scheme 1). ‡ Synthesis and structure of N-alkoxyhydrazines and N-alkoxy-N',N',N'-trialkylhydrazinium salts †

Heteroatom Substitution at Amide Nitrogen—Resonance Reduction and HERON Reactions of Anomeric Amides

“…Pyramidal nitrogens and corresponding anomeric interactions have also been observed in the structures of a number of urea and carbamate analogues of anomeric amides ( 10 – 14 ) studied by Shtamburg and coworkers and selected structural data are presented in Table 2 [66,67,68,69]. Where substituent electronic effects are largely similar as in 11b and 13 , it can be deduced that the stronger conjugative effect of the α-nitrogen lone pair in the urea 11b, relative to the α-oxygen in the carbamate 13, results in significantly less amide resonance interaction and, hence, significant increase in pyramidality at the amide nitrogen.…”

Взаємодія 4-Галогенофенілгліоксалей З N-Алкокси-N’-Арилсечовинами

“…We are deeply convinced that N-hydroxyhydantoins and Nalkoxyhydantoins may bring a huge practical value in the field of pharmaceutical and medical industries as well. Our recent research in the arylglyoxals [10] has shown a completely new way to receive the N-hydroxyhydantoins [11][12][13][14] and N-alkoxyhydantoins [12][13][14][15][16][17][18][19][20][21]. We would like to continue discussing these research results in this article.…”

Heteroatom Substitution at Amide Nitrogen — Resonance Reduction and HERON Reactions of Anomeric Amides

“…structures of a number of urea and carbamate analogues of anomeric amides (10-14) studied by Shtamburg and coworkers and selected structural data are presented in Table 2 [66][67][68][69].…”