Azanone reactions with

The reaction of 2,3,4,5-tetrakis(trifluoromethyl)(yclopenta-2,4-dien-l-one with tertiary phosphines results in nucleophilic attack by the phosphine at carbonyl ojgrgen to form zwitterionic adducts. Nucleophilic attack at carbonyl ojgrgen is also implicated in a phosphine-mediated addition of 1,2-dicarbonyl compounds to nitroso-electrophiles. The diphosphine l,l-bis(diphenylphosphino)methane has been shown to undergo redox reactions with o-quinones, forming phosphine oxides of type (104). An overview of the reactions of HNO (azanone) with metal porphyrins includes reference to O-atom abstraction by phosphines from HNO to form nitrite. ... 

An isomeric mixture of the pyridotriazine derivatives 129 and 130 was obtained in the reaction of 2-aminopyridine with perfluoro-5-azanon-4-ene 128 in the presence of triethylamine in acetonitrile. Compounds 129 and 130 were isolated in 40% and 13% yield, respectively, beside some side products (Equation 16) <2000JFC(103)105>. 

Interaction of iV-pentafluorophenylcarbonimidoyl dichloride with benzonitrile and aluminium trichloride leads to l-pentafluorophenyl-4,6-diphenyl-13 -triazin-2-one along with urea derivatives . Reaction of perfluoro-5-azanon-4-ene with a range of bidentate nitrogen nucleophiles (urea, substituted amidine hydrochlorides and guanidine), in the presence of triethylamine or potassium hydroxide, effectively provides fluorinated 1,3,5-triazines 16-19 <00JFC(103)105>. 

In this case, however, 1-isopropyl-4,4-difluoro-2-hexafluoroethyl-3-tri-fluoromethyl-li/-azetine is formed, which points to a direct reaction of olefin 1 with isopropylamine. This suggests that steric factors play a definite role in this reaction. Indeed, the interaction between olefin 1 and ethylamine is the second route of this reaction. If, however, no isomerization of perfluorolefin takes place under the action of the starting alkylamine, or if a symmetrically substituted structure is formed, then only one heterocyclic compound is obtained. This is realized for perfluoro-5-azanon-4-ene. Irrespective of the character of the nucleophilic reagent, diazete derivative 20 is produced. 

Thus reactions of perfluoro-2-methylpent-2-ene and perfluoro-5-azanon-4-ene with urea in the presence of triethylamine in dipolar aprotic solvents (MeCN, DMF) form 6-fluoro-4-pentafluoroethyl-5-trifluoro-methyl-l//-pyrimidin-2-one 93 and an s-triazine derivative, respectively (00JFC(103)105, 80/82JAP(K)85377). 

It was established (01IZV457) that the products of the reaction of per-fluoro-2-methylpent-2-ene and perfluoro-5-azanon-4-ene with guanidine hydrochloride in the presence of triethylamine are 4-fluoro-6-pentafluoro-ethyl-5-trifhioromethyl-pyrimidin-2-ylamine 101, whose structure was confirmed by X-ray analysis (Fig. 4) and compound 102, respectively. 

Note that in the case of the reaction of guanidine hydrochloride with perfluoro-5-azanon-4-ene one obtains a mixture of products 102 and 103. Compound 103 is the product of further reaction of perfluoro-5-azanon-4-ene with 102. It may be assumed that 103 is formed according to the following scheme ... 

In the reaction of perfluoro-5-azanon-4-ene with 2,6-dimethylaniline, the attack at the carbon atom of the new N=C bond forms a six-membered heterocycle derived from dihydroquinazoline (00JFC(104)263). If the 2,6-positions of the benzene ring of aniline contain electron-donor substituents... 

Me, MeO), then cyclization by the C-anion center is possible. Thus the reactions of perfluoro-2-methylpent-2-ene and perfluro-5-azanon-4-ene with 2,6-dimethylaniline form dihydroquinoline and dihydroquinazoline derivatives, respectively. 

Reaction of perfluoro-5-azanon-4-ene with the amino alcohols 296 in the presence of base affords a convenient route to the oxadiazepine derivatives 297a,b [01JFC11]. 

The reaction of 1 with perfluoro(5-azanon-4-ene) leads, depending on the reaction temperature, to f)erfluoro(3-propyl-4-azaocla-2,4-dicnc) (4) or perfluoro(4-ethyl-5-azanona-3.5-diene) (5). The transfer of the trifluorovinyl fragment to the azamethine molecule presumably results in the initial formation of the products of allyl and vinyl fluorine substitution. ... 

Thus, reaction of the silane, in the presence of cesium fluoride in acetonitrile, with per-fluoro(3-azapent-2-ene) and perfluoro(5-azanon-4-ene) gave phenylazaalkenes 9. 

HNO and NO are, as will be shown in next chapters, very reactive molecules. One of the key reactions is the reaction of HNO with itself (i.e., dimerization) to yield hyponitrous acid (H2N2O2) at nearly diffiisional rate, which decomposes to water and N2O. Therefore, nitroxyl solutions are not stable and HNO, if not produced continuously, readily disappears. Also, HNO cannot be isolated in the sohd state, NO is even more imstable, and its reactivity is less understood. To overcome these problems, working with HNO (or NO ) has always rehed on the use of azanone... 

Rate Constants and Reduction Potentials foe Reactions of Azanone, Azanone Anion, and Nitric Oxide with Biologically Relevant Small Molecules... 

The first studied reactions of azanone with Fe porphyrins were not with isolated porph5rrins, but directly with myoglobin, the benchmark of the heme proteins. 

In this context, the reaction of azanone with isolated iron porph5nins seemed to be a relevant study to be carried out. The first experiments involved the reaction of common, previously described HNO donors such as trioxodinitrate (AS) and tol-uenesulfohydroxamic acid (a PA derivative, TSHA), with several model porphyrins, including the water soluble anionic meso-tetrakis(4-sulfonatophenyl)porphynnate [Fe(III)TPPS] , the cationic meso-tetrakis-N-ethyl pyridinium-2-yl porph3me [Fe(III) TEPyP], as well as the pentacoordinated heme-protein model... 

On the other hand, (case ii) if the reaction of the donor with the metalloporphyrin is faster than its spontaneous decomposition rate, the metalloporphyrin reacts directly with the donor, accelerating its decomposition rate and forming the corresponding nitrosyl complex by azanone transfer to the metal center. For these cases, almost no free HNO is produced, as evidenced by the quantitative formation of the nitrosyl product even for equimolar metalloporphyrin to donor ratios. In these cases, the Uobs against [Donor] plot gives a straight line from which the bimolecular cat(Donor) rate constant can be obtained. 

Kinetic analysis show that the association rate constant for the reaction of the reconstituted globin with azanone is practically the same than that for the free porphyrinate, suggesting that the protein environment is not involved in the reaction mechanism. However, oxidation of the nitrosyl porphyrin inside the protein is ca. 1000 times slower than for the porphyrin in solution, a feature that is ascribed to the role played by the distal residues which protect the nitrosyl product inside the protein matrix (see Scheme 7). 

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