DMF as solvent

DMF as solvent [FORMIC ACID AND DERIVATIVES - DITffiTHYLFORMAMIDE] (Vol 11) Polyurethane dispersions... 

With secondary and tertiary alkyl halides an Ea-elimination is often observed as a side-reaction. As the alkyl halide reactant an iodide is most often employed, since alkyl iodides are more reactive than the corresponding bromides or chlorides. With phenoxides as nucleophiles a C-alkylation can take place as a competing reaction. The ratio of 0-alkylation versus C-alkylation strongly depends on the solvent used. For example reaction of benzylbromide 4 with /3-naphth-oxide 5 in yV,A-dimethylformamide (DMF) as solvent yields almost exclusively the /3-naphthyl benzylether 6, while the reaction in water as solvent leads via intermediate 7 to formation of the C-benzylated product—l-benzyl-2-naphthol 8—as the major product ... 

Similarly applicable for ester syntheses as CDI is A AT -oxalyldiimidazole, which was first described in reference [109]. It has been used to convert not only carboxylic acids but also metal carboxylates into the corresponding imidazolides.[110] Typical reaction conditions for the reactions with oxalyldiimidazole are for the first step 1-2 h, 25-45 °C, and for the second step 4 h, room temperature if X = H if X = Li or Na, if 60 °C and DMF as solvent. In the latter case the resulting Lilm or Naim function as catalysts in the conversion of alcohol into the alcoholate. Results are given in Table 3— 3 [no]... 

A vast improvement for the synthesis of both 3-bromo- and 3-iodoindole by using DMF as solvent was described by Bocchi and Palla, as summarized below [4], This appears to be the method of choice for the preparation of simple 3-bromo- and 3-iodoindoles. 

General conditions DMF as solvent and in situ formation of the EGB by constant potential electrolysis (CPE) at the potential of EGB-formation in a divided cell. 

This is well shy of that needed to reduce either the enone or alkyl halide. Only 1-20 mol% of the mediator is needed, in a medium consisting of LiC104 as the supporting electrolyte, DMF as solvent, and NH4Br as the proton donor. 

Asymmetric induction of between 30 and 66% has been reported for the addition of perfluoroalkyl iodides to chiral arene/chromiumtricarbonyl complexes using ultraso-nically dispersed zinc at room temperature (Scheme 3.19) [101], Photochemical decomposition of the organometallic intermediate affords a chiral alcohol product. The reaction is carried out in DMF as solvent and high overall yields are reported e.g.80 % (R = Et). Only a small excess of the perfluoroalkyl iodide is required and the conversion is complete in under 1 h. 

The competition between ET and 5n2 processes in the reaction between radical anions of various aromatic compounds, e.g. anthracene, pyrene, (E)-stilbene, and m- and / -cyanotoluene, and substrates such as RHal (where R = Me, Et, Bu, 2-Bu, neopentyl, and 1-adamantyl) or various methanesulfonates has been studied in DMF as solvent. The reaction mechanism could be characterized electrochemically in many of the systems indicated above. The presence of an 5n2 component is related not only to the steric requirements of the substrate, but also to the magnitude of the driving force for the ET process. 

Tris-(3,5-di-isopropylsalicylato)iron(III) is a serviceable scavenger for t-butylperoxyl radicals, though it is not as effective as bis-(3,5-di-isopropylsalicylato)manganese(II). An electrochemical study of salicylate and of 2,3- and 3,4-dihydroxy benzoates focused on DMF as solvent. ... 

A straightforward preparation of [Fe4Se4Br4] uses Na2Se, with DMF as solvent.Selenium can replace sulfur in a few high-nuclearity iron-sulfur clusters, e.g., [FegSeg(PEt3)4Cl2] " and... 

Nucleophilic Addition to Carbonyl Compounds and -Unsaturated Carbonyl Compounds.—Although the reactions of 17-oxo-steroids with various carbanion reagents are reported to have varying success/ the use of alcohols or DMF as solvents appears to facilitate the Wittig-Horner reaction/ For example, the ketone (97) was converted with (Et0)2P0CHC02Et into the E-ethyl ester (98) in... 

At temperature lower then 50°C, polymerization proceeds very slowly, whereas at 50°C, 4-vinylpyridine and 2-vinylpyridine polymerize very rapidly without any initiator. Using DMF as solvent, the system remains homogeneous through the polymerization time, whereas in acetone precipitates polymer mixture after a few minutes. It is also... 

The reactions are conducted under inert atmosphere, at room temperature, in DMF as solvent, and in the presence of NEt4C104 as the supporting electrolyte. A divided black zinc is thus obtained. The specific surface area of this zinc (24 to 56 m2/g) is all the larger as the current density applied (usually 60 mA/cm2) during the electrochemical process is low10. 

The procedure given here represents a high-yield reproducible synthesis for salts of [Ni6(CO)12]2- with several counterions, and affords fairly pure products. It involves the reduction of Ni(CO)4 with alkali hydroxide in N, N-dimethylformamide (DMF) as solvent and the use of a low-temperature condenser to prevent Ni(CO)4 loss due to the stripping action of the evolving carbon monoxide. 

Reaction with lactones.1 Under controlled conditions and in DMF as solvent lilhiomethyl isocyanide reacts with lactones to form alcoholic oxazoles (equation I). 

Phthalazine-l,4-diones have been prepared by nucleophilic cleavage of polystyrene-bound phthalimides (Entry 7, Table 15.27). The reaction rate proved to be highly dependent on the solvent used, being low in EtOH but high in DCM. Using DMF as solvent, no phthalazinediones could be isolated [325]. Hexahydropyridazines have been prepared on cross-linked polystyrene in low yields by treatment of support-bound 1-acyloxy-l, 3-dienes with diimide [326]. 

The previously mentioned specific effect of DMF as solvent suggests that it may play an integral role in the reaction, and a possible mechanism for the catalytic action of DMF is shown in Scheme 1. 

In DMF as solvent, PdCl2 or [PdCl2(DMF)2] will catalyze the hydrogenation of conjugated dienes and alkynes to alkenes.194 The above systems quite generally give selective reduction of dienes to monoenes. 

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