1.3- Dimethyl-2-imidazolidinone

All of the alkyl electrophiles shown in Schemes 73-78 are primary alkyl derivatives. On the other hand, cross-coupling of primary alkylzincs with secondary alkyl iodides and bromides was shown to be feasible with 4% Ni(COD)2, 8% s-Bu-Pybox (3) and DMA(N,N-Dimethylacetamide)88k (Scheme 79). More recently, a modification of this procedure through the use of -Pr-Pybox and 7 1 DMI/THF, where DMI is 1,3-dimethyl-2-imidazolidinone, in place of v-Bu-Pybox (3) and DMA has been shown to permit enantioselective alkylation of racemic secondary a-bromoamides with organozincs210 (Scheme 79). 

HomoaUyHc alcohols.1 The reagent reacts with aldehydes and ketones to form derivatives of homoallylic alcohols in satisfactory yield (equation I). 1,3-Dimethyl-2-imidazolidinone is the most satisfactory solvent. 

A very recent study has shown that MCM-41 and HMS-type mesoporous silica are efficient catalysts for the continuous chemical fixation of C02 into 1,3-dimethyl- 2-imidazolidinone with N,N-dimethylethylenediamine in scC02 [133]. 

Interestingly, when 2,3 6,7-bis(trimethylene)naphthalene is treated with sodium ditelluride in HMPTA or 1,3-dimethyl-2-imidazolidinone solution,... 

Thermolysis of the seleno-bridged 1,2-diazocine 7, in absence of solvent at 115-130 °C, led by simultaneous extrusion of nitrogen and selenium to the l,2-di-/-butyl-3,3,6,6-tetramethylcyclohexene in 43% yield. The same compound was obtained in lower yield (7%) when the thermolysis of 7 was conducted in refluxing 1,3-dimethyl-2-imidazolidinone (DMI Scheme 4) <2000JOC1799>. 

Reaction of 1 and related silyl anions with 1,3-dienes gives 1,4-disilyl-2-butenes. The (E)-isomer is the exclusive or major product. HMPT or 1,3-dimethyl-2-imidazolidinone (DMI) is essential. 1,3-Dienes substituted at C, and/or C4 do not undergo this reductive disilylation. 

Little selectivity is observed in hydrocarbon solvents, but use of DME or THE markedly improves. syn-selectivity, particularly when TMEDA or 1,3-dimethyl-2-imidazolidinone (DM1) is added. Low temperatures are also important. Even so, little stereoselectivity obtains if R and R- are of similar size. For highest selectivity, R- should be larger than R. ... 

Dimethyl-2-imidazolidinone Dimethylisopropylsilyl Dimethylmaleoyl Dithianylmethoxy carbonyl Dimethylphosphinyl... 

Allyl iodide undergoes an oxidative metalation upon treatment with Snp2 in 1,3-dimethyl-2-imidazolidinone (DMI) [44]. The resulting allyl iododifluorotin species adds to aldehydes to afford homoallylic alcohols (Table 28) The reaction can also be performed with SnCh or SnBr2. 

Dimethyl-2-imidazolidinone, 6, 374 Dimethylmaleic anhydride, 187 Dimethyl(methylene)ammonium hahdes,... 

Synthesis of Aromatic Nitriles from Esters. A one-flask method has been developed for the conversion of aromatic esters to the corresponding nitriles by use of NaHMDS in a sealed tube at 185 °C in a mixture of THF and 1,3-dimethyl-2-imidazolidinone (DMEU) (eq 20). The transformation proceeded with good to excellent yields. The synthetic strategy is only apphcable to aromatic esters that bear an electron-donating substituent such as hydroxy or methoxy. In the latter case, con tetitive 0-demethyla-tion is observed, thus leading to a mixture of nitrile products. The reaction has been also applied to indole-3-carboxylate. However, simple unsubstituted methyl benzoate failed to give the desired product. 

Dimethyl imidazolidinone CAS 80-73-9 EINECS/ELINCS 201-304-8 Synonyms N,N -Dimethylethyleneurea 1,3-Dimethyl-2-imidazolidinone 1,3-Dimethylimidazolidin-2-one DMI 2-Imidazolidinone, 1,3-dimethyl-Classification Heterocyclic organic compd. Empirical C5H10N2O... 

From the synthetic point of view, more flexibility is achieved by employing non-aqueous non-derivatizing solvents. Extensive work has been carried out on binary or ternary mixtures like inorganic or organic electrolytes in strongly dipolar aprotic solvents. The best known example is LiCl in DMA, in A-methyl-2-pyrrolidone (NMP), or in 1,3-dimethyl-2-imidazolidinone (DMI) [5]. The structure of these ceUulose/solvent system complexes has been described by several authors, differing essentially in the role played by the Li and CD ions, as comprehensively discussed in a specific review [6]. 

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