Photoreaction of Nitroso Compounds in Solution. Part XXXI. Mechanisms of Intramolecular Acid Catalyzed Cleavage Reactions and a Hydride Initiated Rearrangement of C-Nitroso Alkanes

Abstract

CHOW. Can. J. Chem. 53,3014(1975).Two novel rearrangements of nitroso alkanes, one intramolecular acid catalyzed cleavage reaction and the other ring enlargement during hydride reduction, are described. Aminium radical initiated addition to norbornene under nitrogen gave cis-exo-and trans-2-nitroso-3ammonium norbornanes in a good yield. Whereas the trans isomer underwent the usual nitroso group reactions, i.e., tautomerization, dimerization, and HNO addition, the cis-exo isomer and its hydroxy analog cleaved extremely readily to give 1,3-bisformylcyclopentane derivatives. The stereoelectronic driving force in this cleavage is interpreted as the intramolecular proton transfer and the electron reorganization via a cyclic transition state. Metal hydride reduction of the trans isomer was accompanied by ejection of the neighboring amino group and an expansion of the ring to form an azabicyclic compound. A sequence involving an intramolecular displacement to form aziridine followed by the reductive cleavage is proposed. K. SOMOSEKHAREN PILLAY, SHI C. CHEN, THOMAS MOJELSKY et YUAN L. CHOW. Can. J. Chem. 53,3014 (1975). On decrit deux nouveaux rearrangements des nitroso alkanes: une reaction de coupure intramolCculaire catalyske par les acides et une autre impliquant une expansion de cycle au cours d'une reduction par les hydrures. L'addition au norbornene initiee par le radical amminium, se fait sous atmosphere d'azote et conduit, avec de bons rendements, aux cis-exo-et trans-nitroso-2 ammonium-3 norbornanes. Alors que le groupe nitroso de I'isomkre trans reagit normalement, a savoir tautomerisation, dimkisation et addition de HNO, l'isomtre cis-exo et son analogue hydroxyle se coupent extrtmement facilement pour conduire aux derives bisformyl-1,3'cyclopentanes. On suggere que la force stCreotlectronique aidant cette rupture est le transfert intramolCculaire d'un proton et la reorganisation electronique par I'intermediaire d'un Ctat de transition cyclique. La reduction de I'isomtre trans par les hydrures complexes est accompagnee par une expulsion du groupe amino voisin et par une expansion de cycle conduisant a un compost azabicyclique. On propose un mecanisme impliquant un deplacement intramoleculaire conduisant a une aziridine qui serait ensuite coupee lors de la reduction. [Traduit par le journal] 5 -9 5 R,, R, = CH(OCH,), 6 R, = CHO; R, = CH(OCH,), 7 R, = CH(OCH,),; R, = CH=NOH 8 R,, R, = CHO 9 R, = CHO; R, = CH=NOH

Chemistry of the Nitric Oxide-Releasing Diazeniumdiolate (“Nitrosohydroxylamine”) Functional Group and Its Oxygen-Substituted Derivatives

“…In a recent direct example, nitroxyl derived from Angeli's salt (Na 2 N 2 O 3 , an O-diazeniumdiolate, see later) was trapped by nitrosobenzene to produce Cupferron. 82 The reaction also explains the production of diazeniumdiolates in the photolysis of N-nitrosoamines in the presence of olefins [83][84][85] (via addition of HNO formed from the N-nitrosoamine to the C-nitroso compound formed by addition of the N-nitrosoamine to the olefin) and in the reaction of monoalkylhydroxylamines with nitric oxide. 86 Conversion of C-nitroso dimers to diazeniumdiolates was first reported in 1895.…”

Preparations ofC-Nitroso Compounds

“…146 Similarly, dimethylnitrosamine undergoes photoaddition to norbornene (eq 18). 147 An interesting analogous synthesis is provided by the photoaddition of N-nitrosopiperidine to phenylacetylene followed by hydrolysis to form phenylglyoxal ketoxime, which tautomerizes to give the dimer of 1-nitroso-2-hydroxystyrene (Scheme 10), 148 a compound which merits a full structural study.…”

Synthesis of azacyclic compounds by an aminium radical route: orbital overlap requirements

“…The next lower signal centered at T 6.57, equivalent in intensity to four protons, could be assigned to the C-2 and C-6 protons. The unusually low ?-values for protons geminal to an amine group had been observed in another hydroxylamine derivative (54), and suggested that 22 might be a zwitterion in which the amine group was protonated by the nearby weakly acidic Nnitrosohydroxylamino group.…”