Conformations of four-membered ring hydrazines and hydrazine radical cations

Abstract

Photoelectron spectra of 1,2-dialkyl-1,2-diazetidines show that the 1,2-dimethyl compound (1) exists overwhelmingly in the "diequatorial" trans conformation, while a significant amount of the "diaxial" trans conformation is detected for the diisopropyl compound (2), and the tricyclic structure holds the diazetidine ring in nearly eclipsed geometry for 3,4-dimethyl-3,4-diazatricyclo[4.2.1,02•5]non-7-ene (4) and its saturated analogue (3). Although A-dimethylaminoazetidine (5), TV-dipropylaminoazetidine (6), and biazetidine (8) are predominantly in gauche conformations, the anti conformation predominates for A-piperidinylazetidine (7). The rates of double nitrogen inversion for 3 and 4 are nearly identical and increase slightly with increasing solvent polarity, and SG*29S is about 3.8 kcal/mol lower than for 1. The ESR splitting constants for the cations from 1, 2, and 8 are reported, and compared to those for other tetraalkylhydrazine radical cations.

Density Functional Theory Study of 14N Isotropic Hyperfine Coupling Constants of Organic Radicals

“…Radicals 2-33 correspond to N-centered radicals: alkylaminyl radicals (2-8); radical cations of acyclic alkylamines (9)(10)(11)(12)(13)(14)(15)(16)(17)(18); radical cations of cyclic alkylamines (19)(20)(21)(22)(23)(24)(25)(26); iminyl radicals (27)(28)(29)(30)(31); azaphenyl radicals (32 and 33). Radicals 34-63 correspond to NN-centered radicals: alkylhydrazyl radicals (34)(35)(36)(37)(38)(39); radical cations of alkylhydrazines (40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53); radical cations of alkyldiamines (54)(55)(56)(57); radical ions of alkylazoalkanes (58-63). Radicals 64-106 correspond to NOand NO 2 -centered radicals: alkylnitroxyl radicals (64-79); radical anions of nitroalkanes (80)…”

[1 + 3] Cycloadditions of isocyanides to azomethine ylides; synthesis and properties of 1-phthalimidoazetidines

“…However, this result is in contrast to the stability of 1-aminoazetidine,15 l-amino-2,4-dimethylazetidine,16 and l-(dialkylamino)azetidines. 17 The instability of 30 resembles that of certain 1-aminoaziridines.18-20 The extrusion of aminonitrene from 30 would be expected to give some cyclopropane via the trimethylene intermediate. 16 No cyclopropane was found, and we propose that the reaction proceeds by cleavage of the C-N bond in 30 to give the intermediate 31 (Scheme V), as in the Wolff-Kishner reduction.…”

Silver(I)-catalyzed oxidation of cyclic secondary amines with peroxodisulphate

“…Authentic Sample of 1 -FormyZperhydroazocine (1 3).-A mixture of perhydroazocine (12) (3.28 g, 29 mmol) and ethyl formate (1 1 g, 149 mml) was refluxed for 1 h. Evaporation under reduced pressure gave an oily residue (4.2 g). Kugel-Rohr distillation (100 "C/O3 mmHg) of the residue (2.1 g) afforded compound (13) as a colourless oil (1.3 g, 64%) (Found: C, 67.9; H, 10.9; N, 9.6. CsHlSNO requires: C, 68.04; H, 10.71; N, 9.92%); v, , (neat) 1675-1 655 cm-l (amido CO); 6, (CDCl,) 8.1 (1 H, s), 3.5-3.2 (4 H, m), and Oxidation of Azetidine (7).-Azetidine (7.06 g, 124 mmol) was oxidized in a similar manner to piperidine.…”