Magnesium imides

The formation of imides could be excluded since ammonia could be expelled with magnesium hydroxide from the samples (outgassed at 100°). 

The metallation should proceed via the formation of a chelated tetrahedral magnesium enolate complex, with a (Z)-geometry. The conformational rigidity would be enforced by chelation of both the imide enolate and bis(sulfonamide) ligand to the tetrahedral magnesium ion. 

The enantioselective amination of iV-acyl oxazolidinones has been studied as part of a general approach to the synthesis of arylglycines. In this case, the enolization is initiated by a chiral magnesium bis(sulfonamide) complex. The oxazolidinone imide enolates are generated using catalytic conditions (10 mol% of magnesium complex) and treated in situ with BocN=NBoc to provide the corresponding hydrazide. 20 mol% of iV-methyl-p-toluensulfonamide are added to accelerate the reaction (equation 117). 

In earlier sections it has been shown that the reaction of a magnesium dialkyl with one equivalent of a primary amine usually affords the primary amido derivative. However, it is also possible to effect elimination of the second equivalent of alkane to give magnesium imides. The reaction of MgEt2 with aniline in thf proceeded via an amido intermediate which eliminated ethane to yield the hexameric imido compound [ (thflMgNPhJg] which was the first homometallic magnesium imide to be structurally characterized. Equation (3.9). 

Other than [(thf)3Ca(AlH)3(NBu )4], no molecular calcium imides related to those described for magnesium in Section 3.3.7, are currently known. Crystals of the parent imide CaNH have been shown to have a structure similar to that of NaCl. ... 

Ammonia, Lithium amide. Lithium Imide. Lithium nitride. Magnesium nitride. 

Nitrile oxides react with the methyl enol ethers of (Rs)-l -fluoro-alkyl-2-(p-tolylsulfinyl)ethanones to produce (45,5/f,/fs)-4,5-dihydroisoxazoles with high regio-and diastereo-selectivity.87 In the 1,3-dipolar cycloaddition of benzonitrile oxide with adamantane-2-thiones and 2-methyleneadamantanes, the favoured approach is syn, as predicted by the Cieplak s transition-state hyperconjugation model.88 The 1,3-dipolar cycloaddition reaction of acetonitrile oxide with bicyclo[2.2.l]hepta-2,5-diene yields two 1 1 adducts and four of six possible 2 1 adducts.89 Moderate catalytic efficiency, ligand acceleration effect, and concentration effect have been observed in the magnesium ion-mediated 1,3-dipolar cycloadditions of stable mesitonitrile oxide to allylic alcohols.90 The cycloaddition reactions of acryloyl derivatives of the Rebek imide benzoxazole with nitrile oxides are very stereoselective but show reaction rates and regioselectivities comparable to simple achiral models.91. 

Thecouple jMg2+ + e - Mg, with the cation present as the salt Mg(CFsSOs)2 (1 M) has been used as a reference electrode in N-propyl-N-methylpiperidinium bis(trifluoromethylsulfonyl)imide [C3mPip][NTf2] [47]. The authors also considered the use of a magnesium ribbon as a pseudo-reference electrode. The RTIL... 

The compounds, silver imide and aluminum nitride, are largely covalent but hydrolysis of either yields ammonia, just as do the hydrolyses of the ionic compounds sodamide or magnesium nitride thus none of these compounds is stable in the presence of moisture. Since water is a stronger... 

Synthesis of Siloxane-Polyimide Elastoplastics. In a typical polymerization, a 5-L, three-neck, round-bottom flask equipped with an overhead mechanical stirrer, a Dean-Stark trap with condenser and a nitrogen inlet, and a thermometer was charged with 484.00 g (0.2406 mol) of D2o-DiSiAn, 41.61 g (0.431 mol) of mPD, 19.52 g (3 wt %) of 2-hydroxypyridine, and 2 L of o-dichlorobenzene. The mixture was warmed to 100 °C for 1 h to dissolve the monomers and the catalyst. The polyamic acids precipitated and then redissolved when the mixture was warmed to 150 °C for 2 h. To the oligomer solution was added 99.13 g of BPADA dissolved in 200 mL of o-dichlorobenzene. The mixture was maintained at 150 °C for an additional 2-h period to ensure incorporation of the dianhydride and then warmed to reflux. After approximately 100 mL of a solvent-water mixture had been removed, the solution was maintained at 180 °C for 40 h. The mixture was cooled to room temperature and diluted with 1 L of methylene chloride. Polymer was isolated from the solution by a slow addition of the polymer solution to 4 L of methanol. The resulting slurry was filtered, and the polymer was redissolved in 4 L of methylene chloride, extracted three times with 2 N aqueous HCl to remove catalyst, washed with water, dried with magnesium sulfate, reprecipitated into methanol as before, filtered, and dried in vacuo at 100 °C to obtain 522 g (85%) of a rubbery material with an IV of 0.50 dL/g. IR, NMR, and Si NMR spectroscopic analysis indicated the absence of amic acid functionalities that could be present if imidization is incomplete. 

Metal amides can be added to ordinary nitriles e.g. lithium, sodium or magnesium amides), thus forming amide imide salts, which on addition of water or alcohol afford amidines. Some recent results demonstrate the wide applicability of the method, e.g. from metal amides and trialkoxyacetonitriles, tri-alkoxyacetamidines (319 Scheme 52) were prepared and from lithium imides and nitriles A -alkylide-neamidines (320) could be synthesized. 

Magnesium amides and imides have provided to be useful as possible transfer agents for -NR2 and -NR ligands to transition metals. The magnesium imide Mg(NPh)(THF) has been reported as a suitable transfer agent for the imido... 

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