Dimethyl formamide adduct

Nitroalkanes react with Jt-deficient alkenes, for example, p-nitro ketones are produced from a,P-unsaturated ketones [41], whereas allylic nitro compounds have been prepared via the Michael-type addition of nitroalkanes with electron-deficient alkynes (Table 6.19). The reaction in either dimethylsulphoxide [42] or dimethyl-formamide [43] is catalysed by potassium fluoride in the presence of benzyltriethyl-ammonium chloride the reaction with dimethyl acetylenedicarboxylate is only successful in dimethylsulphoxide [42], Primary nitroalkanes produce double Michael adducts [42,44], A-Protected a-aminoacetonitriles react with alkynes under catalysed solidiliquid conditions to produce the Michael adducts [45] which, upon treatment with aqueous copper(Il) sulphate, are converted into a,p-unsaturated ketones. 

Solid Mo02Br2(DMF)2 melts at 139-141°C with decomposition. The IR spectrum, taken as a KBr dispersion, has characteristic bands for i moO 903 and 940 cm The NMR spectrum in acetone-t/g exhibits signals at S 3.03 (s, 3H, CHa), 3.22 (s, 3H, CH3), 8.26 (s, IH, CH). The complex is insoluble in hexane and diethyl ether and is soluble in methanol, ethanol, dichloromethane, chloroform, acetone, dimethyl formamide, and dimethyl sulfoxide. It is stable in air at room temperature and can be manipulated without special care. This product is specially useful for the synthesis of a number of adducts with pyridine and related bases, since the dimethyl formamide displaced can be readily removed by washing with most common organic solvents. 

Anhydrous lanthanide adducts with dimethyl formamide (DMF) [4], dimethyl sulphox-ide [5] (DMSO) and hexamethyl phosphoramide [6] may be used for the synthesis of anhydrous complexes as long as their solvation does not interfere with the preparative reaction [7],... 

Reaction of sodium dithiocarbamate with an equimolar amount of the chloroacetaldehyde/sodium hydrogen sulfite adduct (110) in dimethyl-formamide at room temperature yields 111 quantitatively. The latter, treated first with concentrated sulfuric acid and then with sodium tetraphenylborate, gives the salt 112 in 86% yield.Under the same conditions, piperi-dinium dithiobenzoate reacts with 110 providing in 64% yield 2-phenyl-l,3-dithiolium tetraphenylborate. ... 

A series of cyclizations to benzene derivatives during formylation reactions with dimethylchloromethyleneammonium chloride or the related adduct of dimethyl-formamide-phosphorylchloride has been observed125. ... 

Similarly, pteridine-6-carbaldehyde 2a after conversion to the oxime 3 can be transformed to the corresponding nitrile oxide with (V-chlorosuccinimide in dimethyl formamide, followed by treatment with friethylamine in the presence of a dipolarophile, to give good yields of cycloaddition products 4.254 These adducts are hydrolyzed to the 2-amino compounds by heating to 70-80°C with 1 M hydrochloric acid in dioxane. 

Dimethyl formamide Urea adducts Paraffins Furfural, furfural alcohol. Cycle oil Heavy aromatics... 

The nature and the amount of solvent can influence the yield and the composition of the copolymers in these copolymerizations. Copolymerization of phenanthrene with maleic anhydride in benzene yields a 1 2 adduct. In dioxane, however, a 1 1 adduct is obtained. In dimethyl formamide no copolymer forms at all. Another example is a terpolymerization of acrylonitrile with 2-chloroethyl vinyl ether and maleic anhydride or with p-diaxene-maleic anhydride. The amount of acrylonitrile in the teipolymer increases with an increase in the r-electron density of the solvent in the following order ... 

From carbonohydrazide. Equimolar quantities of carbonohydrazide (71) and aroyl isothiocyanates undergo an addition-cyclization in dimethyl-formamide at 100 °C, with elimination of hydrazine, resulting in moderate yields of 2-aroylamido-5-hydroxy-l,3,4-thiadiazoles (73). The postulated intermediate mono-adducts (72) are not isolable, but stable addition... 

Abstract - This work is concerned with the origin of effects on rate equilibrium processes when reactions are performed in dipolar aprotic media such as dimethyl sulfoxide and dimethyl-formamide compared to typical hydroxylic media. An example of processes studied in our laboratory is the competition between proton abstraction and a-complex (Meisenheimer adduct) formation in the interaction of nitroaromatic compounds with basic systems (e.g. 1,3-dinitrobenzene in DMF-D20-Na0D). Other reactions studied are the base catalyzed isotopic exchange of D2 in aqueous DMSO mixtures, and also isotopic exchange of fluoroform. It has been found possible in certain cases to dissect the initial state and transition state contributions to the reaction rates from the kinetically measured enthalpies of activation and the thermodynamically evaluated enthalpies of transfer of the reactants. This procedure affords insight into transition state properties and behaviour. 

Many noticeable examples of chiral Lewis base catalyzed allylation of carbonyl compounds have also appeared. Iseki and coworkers published a full paper on enantioselective addition of allyl- and crotyltrichlorosilanes to aliphatic aldehydes catalyzed by a chiral formamide 28 in the presence of HMPA as an additive [41]. This method was further applied to asymmetric allenylation of aliphatic aldehydes with propargyltrichlorosilane [40]. Nakajima and Hashi-moto have demonstrated the effectiveness of (S)-3,3 -dimethyl-2,2 -biquinoline N,AT-dioxide (29) as a chiral Lewis base catalyst for the allylation of aldehydes [42]. In the reaction of (fs)-enriched crotyltrichlorosilane (54 , E Z=97 3) with benzaldehyde (48), y-allylated anfi-homoallylic alcohol 55 was obtained exclusively with high ee while the corresponding syn-adduct was formed from its Z isomer 54Z (fs Z= 1 99) (Scheme 6). Catalytic amounts of chiral urea 30 also promote the asymmetric reaction in the presence of a silver(I) salt, although the enantioselectivity is low [43]. 

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