Hydrazines diimides

Dia ene deductions. Olefins, acetylenes, and azo-compounds are reduced by hydrazine in the presence of an oxidizing agent. Stereochemical studies of alkene and alkyne reductions suggest that hydrazine is partially oxidized to the transient diazene [3618-05-1] (diimide, diimine) (9) and that the cis-isomer of diazene is the actual hydrogenating agent, acting by a concerted attack on the unsaturated bond ... 

Repeat your analysis for pyridazine. Do any of the resonanee eontributors provide an adequate deseription of its geometry Does pyridazine incorporate a nitrogen-nitrogen double bond (Refer to hydrazine and to diimide as examples of moleeules ineorporating NN single and double bonds, respeetively.)... 

The available studies indicate that diimide has been used as a reducing agent for the preparation of HNBR. It has been used mainly as an alternative for hydrogenation of nitrile rubber latex. The use of diimide to hydrogenate low-molecular weight olefines is well known in the organic literature [93]. Diimide can be conveniently generated in situ by thermal treatment of solutions of p-tolu-enesulfonyl hydrazide or oxidation of hydrazine. 

In the above-mentioned reactions with hydrazine and hydroxylamine, the actual reducing species is diimide (NH=NH), which is formed from N2H4 by the oxidizing agent and from NH2OH by the ethyl acetate.The rate of this reaction has been studied.Although both the syn and anti forms of diimide are produced, only the syn form reduces the double bond, at least in part by a cyclic mechanism ... 

Diimide from hydrazine hydrate Diimide can be generated from hydrazine hydrate by oxidation with this hypervalent iodine compound in CH2C12. 

S-S Wang, ID Kulesha, DP Winter, R Makofske, R Kutny, J Meienhofer. Preparation of protected peptide hydrazides from the acids and hydrazine by dicyclohexylcarbo-diimide-hydroxybenzotriazole coupling. Int J Pept Prot Res 11, 297, 1978. 

Since diimide exists as a transient intermediate and cannot be isolated under normal conditions, procedures for reduction by diimide necessarily involve generation of the reagent in situ1 1 11. Diimide can be generated by (i) oxidation of hydrazine, (ii) acid decomposition of azodicarboxylate salts and (iii) thermal or base-catalyzed decomposition of substituted benzenesulfonyl hydrazides. 

The checkers observed only partial reduction of the triene and intermediate diene under these conditions, apparently because sufficient water was present in the reaction mixture to prevent adequate partitioning of the olefins between the hydrocarbon layer and the aqueous ethanolic layer containing the diimide. The checkers avoided this difficulty by use of hydrazine containing less than 5% water (95-f- % hydrazine) available from Olin Mathieson Chemical Company or from Eastman Organic Chemicals. This difficulty could probably also be avoided by use of absolute ethanol rather than 95% ethanol. 

The procedure described is based on the selective reduction with diimide described by Ohno and Okamoto and by Nozaki and Noyori. It illustrates the generation of diimide from the air oxidation of hydrazine and the use of diimide for the selective reduction of the trans double bond in cis,trans,trans-, S,9-cyc o-dodecatriene, the product of trimerization of butadiene. ... 

Diimide diimine, diazene), N2H2 or HN=NH, is an ephemeral species which results from decomposition with acids of potassium azodicarboxylate [264, 265] from thermal decomposition of anthracene-9,10-diimine [266, 267], and of hydrazine [268,269] and its derivatives [270]. Although this species has not been isolated, its transient existence has been proven by mass spectroscopy and by its reactions in which it hydrogenates organic compounds with concomitant evolution of nitrogen [271]. 

The behavior of dienes and polyenes - both open chain and cyclic - toward reduction depends especially on the respective positions of the double bonds. Carbon-carbon double bonds separated by at least one carbon atom behave as independent units and can be partly or completely reduced by catalytic hydrogenation or by diimide. cis, trans, /rani-l,5,9-Cyclododecatriene treated with hydrazine and air in the presence of copper sulfate (diimide in situ) gave cij-cyclododecene in 51-76% yield [269]. It appears as if the trans double bonds were reduced preferentially. 

Primary amines can be reduced to their parent compounds by treatment with hydroxylamine-O-sulfonic acid and aqueous sodium hydroxide at 0°. Substituted hydrazines and diimides are believed to be the reaction intermediates in the ultimate replacement of the primary amino group by hydrogen in yields 49-72% [708],... 

Conjugated oximes were converted to pyrazoles in a one-pot reaction by refluxing with hydrazine and iodine in ethanol. The process proceeds via an inverse electron-demand Diels-Alder reaction involving electron-deficient heterodienes and diimide species as dipolarophiles . ... 

The 1,2,3,4-isomer is also the major product if other reduction reagents [7] such as anhydrous hydrazine [6], diimide [3] or palladium hydride wrapped in gold foil [15] are used. Contrary to this result, reduction with wet Zn/Cu couple (Section 5.2.2) does not lead to the cis-l-adduct. Instead the e-isomer and the trans-3-isomer are formed as major products [5]. 

The redox reactions of hydrazine toward main-group and transition metal oxidants have been reviewed (73). Different stoichiometries have been found, with N2 appearing as the N-containing oxidized product, sometimes accompanied by the formation of NH3 and/or HN3. The mechanisms have been analyzed in terms of the one- or two-electron nature of the oxidants, and imply both outer-and inner-sphere routes, depending on the oxidant. The very reactive, key intermediate, diazene (diimide), N2H2, has been proposed in most of these reactions. 

The reagent can be prepared in situ, by the copper-catalyzed oxidation of hydrazine. Hydrogen peroxide or oxygen are often the oxidants. The acid-catalyzed decomposition of potassium azodicarboylate provides a useful source of diimide ... 

The carbon-carbon double bond can be reduced by diimide prepared in solution in a number of ways.34 183,184 Oxidation of hydrazine with oxygen (air) or H202 in the presence of a catalytic amount of Cu(II) ion was the first method to generate and use diimide in hydrogenation.183-185 Acid-catalyzed decomposition of alkali azido-dicarboxylates,185,186 as well as thermal or base-catalyzed decomposition of aromatic sulfonyl hydrazides,183,184 are also useful methods for preparing the diimide reducing agent. 

Hydrazine actually has been used as a hydrogenating agent for over sixty years, but it was not until the 1960 s that the diimide intermediate in such reactions was recognized. 

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