Silver nitrite-iodine

The iodine atom in iodobenzene (unlike that in the corresponding aliphatic compounds) is very resistant to the action of alkalis, potassium cyanide, silver nitrite, etc. This firm attachment of the iodine atom to the benzene ring is typical of aromatic halides generally, although in suitably substituted nitio-compounds, such as chloro-2,4-dinitrobenzene, the halogen atom does possess an increased reactivity (p. 262). 

Replacement of silver nitrite by inexpensive sodiiunor potassium nitrite enhances the imlity of this process Treatment of alkenes v/ith sodiiun nitrite and iodine in ethyl acetate and water in the presence of ethylene glycol gives conjngatednitroalkenesin49-82% yield The method for generation of nitryl iodide is improved by the treatment of iodme v/ith potassium nitrite complexed v/ith 18-crovm-6 in THF under sonicadon, as shovmin Eq 2 32 ... 

In exptl work, indirect methods of introducing nitro groups find wide application as, for example, the replacement of a halogen (iodine or bromine in an alkyl iodide or bromide) by the nitro group, by means of silver nitrite (the Victor Meyer reaction)... 

The synthetic applications of this reagent to the synthesis of nitroalkenes have been known since the 1960s.60 Nitration of alkenes with nitryl iodide, generated in situ from iodine and silver nitrite, is convenient for the synthesis of P-nitrostyrenes with various functional groups.61 This method is applied to the synthesis of ortho-methoxylated phenylisopropylamines, which are potent serotonine agonists (Eq. 2.31).62... 

Aromatic cation-radicals can also react with NOj", giving nitro compounds. Such reactions proceed either with a preliminary prepared cation-radical or starting from nncharged componnd if iodine and silver nitrite are added. As for mechanisms, two of them seem feasible—first, single electron transfer from the nitrite ion to a cation-radical and second, nitration of ArH with the NOj radical. This radical is quantitatively formed when iodine oxidizes silver nitrite in carbon tetrachloride (Neelmeyer 1904). 

A mixture of silver nitrite and iodine reacts with alkenes to give jS-nitroalkyl iodides, and therefore, provides a convenient route to a-nitroalkenes. Treatment of alkenes with ammonium nitrate and trifluoroacetic anhydride in the presence of ammonium bromide, followed by... 

When the reaction of methyl 5,6-dideoxy-2,3-di-0-p-tolylsulfonyl-a-L-arafoino-hex-5-enofuranoside with silver nitrite and iodine was performed in more-polar solvents, such as methanol and acetonitrile, a /3-iodo nitrate was produced, in addition to the C-iodo-C-nitro adduct 88 in methanol, the ratio of the two products was130 3 2. The /3-iodo nitrate was identical with the adduct obtained by the reaction of the alkene with silver nitrate and iodine in acetonitrile.132 The formation of the /3-iodo nitrate in the silver nitrite-iodine reaction in polar solvents may be due to the increased solubility of the silver nitrite the available nitrite ions could then be oxidized to nitrates. The positions of the iodo and nitrate groups in the adduct have not yet been established. 

The use of the pseudohalogen nitryl iodide, prepared in situ from iodine and silver nitrite, has been found to add to an alkene in what is strictly an anti-Markownikov fashion. The explanation for this lies in that nitryl iodide adds in a radical manner, initially forming the more stable secondary radical after addition of NO2.115 Treatment of 3-0-acetyl-5,6-dideoxy-1,2-0-isopropylidene-a-D-xy/o-hex-5-enofuranose with nitryl iodide was found to afford an unstable adduct, with the nitro group appended to C-6, and iodine attached to the more substituted C-5.116-118 Similarly, treatment of benzyl 2-0-benzyl-3,4-dideoxy-a-D-g/ycero-pent-3-enopyranoside (70, Scheme 19) with nitryl iodide afforded the unstable adduct 71, which, upon exposure to mild base (NaHC03), afforded the eliminated product, namely benzyl 2-0-benzyl-3,4-dideoxy-4-nitro-a-D-g(ycew-pent-3-enopyranoside (72). The eliminated product was then readily converted into benzyl 2-0-benzyl-3,4-dideoxy-(3-L-r/ireo-pentopyranoside (73) by reduction with sodium borohydride. Addition of deuteride using NaBD4 led to axial deuteration atC-3. 

After investigating the reaction in order to control its stereochemistry, they succeeded in improving this approach considerably, as shown below. Introduction of a nitro group into the known styrene 302 by reaction with silver nitrite in the presence of iodine, gave the nitrostyrene 303 in 72% yield. Heating of 303 at 120°C gave the cis-fused adduct 304 stereoselecti-vely in 97% yield. Treatment of the nitro compound 304 thus obtained with titanium trichloride furnished the sensitive ketone 305. Concomitant reduction of the carbonyl and urethane groups of the crude product with LAH afforded ( )-chelidonine in 54% yield from 304 (146) (Scheme 111). 

Nitryl iodide, from iodine with silver nitrite or from NO2 and iodine, adds to alkenes, generally in ether at room temperature, by a radical mechanism. Yields are 50-90%. The products yield nitroalkenes on treatment with base, a sequence used recently in the preparation of intermediates (ArCH—CMeNOa) for amphetamine analogs. The reaction is also a key step in the a-methylenebuty-rolactone synthesis shown in Scheme... 

Nitryl Iodide, INO2. Mol. wt. 172.92. Hassner and co-workers generated this reagent in situ in ether solution at room temperature from one equivalent of silver nitrite and iodine in a nitrogen atmosphere. They found that it adds to some olefins, for example, to A -cholestene ... 

It is reported that dibromofuroxan reacts slowly with diethylamine in ether, to afford a mixture of bisdiethylaminofuroxan and bisdiethylamino-glyoxime.246 Dioximes are also produced in its reaction with ammonia, hydroxylamine, and aniline the last reagent is also oxidized to aniline black. Dichlorofuroxan behaves similarly.83 The dichloro compound rapidly liberates iodine from iodide ion, oxidizes aniline, and forms hygroscopic salts of uncertain composition with aqueous sodium hydroxide, but it does not react with silver nitrite in ether.83... 

The crystal structure of the gold(i) complex [CeF5Au(PPhs) ] has been determined. It is approximately linear with a C—Au—P bond an e of 17go 302 The chlorine in chlorobis(pentafluorophenyl)triphenylphosphine-gold(iii) may be replaced by Br, NOj, or OAc, using potassium bromide, or silver nitrite or acetate in acetone, but an excess of potassium or silver salt causes liberation of periluorobiphenyl. It is not possible to introduce iodine using KI, but the iodo-compound is available by the route ... 

Silver perchlorate iodine sodium nitrite Nitration via radical cations... 

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