Lithium methide

Comparison of stability limits of low-temperature molten salts and lithium salts with a common anion shows the influence of the solvent, which limits the anodic stability range of solutions based on LiMe or Lilm. The 1,2-dimethyl-3-propylimidazolium methide... 

Cycloaddition Anodically generated phe-noxy cations, o-quinones, and o-quinone methides react with olefins to bicyclic and tricyclic annelated compounds in stereoselective cycloadditions [250-252]. In the synthesis of a Euglobal skeleton, a quinone methide has been generated in situ by anodic oxidation mediated by DDQ. The cycloaddition was promoted by the use of lithium perchlorate... 

A procedure for converting an aldehyde or ketone RR CO to the homologous aldehyde RR CHCHO consists of treating the substrate with lithium bis(ethylenedioxyboryl)methide, followed by oxidation with aqueous H2O2 602... 

Ah initio calculations on the competing metallo-dehydrogenation and nucleophilic addition reactions of organomethides with crotonaldehyde dimethylacetal reveal that addition to the double bond predominates in the case of lithium whereas this is only slightly preferred in the case of potassium methide the effect of R OK on deaggregation of RLi oligomers and on weakening C —Li+ interaction has been discussed.104... 

Lithium aluminum hydride-1-)-N-Methyl-ephedrine, 238 Lithium arenesulfonates, 69 Lithium benzeneselenOlate, 238-239 Lithium bis(ethylenedioxyboryl)methide,... 

Lithium tris(Trifluoromethane sulfonyl)methide (Li Tri TFSM) 3. Lithium pentafluoro sulfur difluoro Li C(S02CF3)3a 112... 

Ytterbium(lll) tris(perfluoroalkanesulfonyl)methides 34 are effective catalysts (10% mol) for the Friedel-Crafts acylation of arenes with anhydrides. Compounds 34 can be prepared as described in Scheme 3.7. Trimethylsilylmethyl lithium 31 is reacted with commercially available per-fluoroalkanesulfonyl fluorides, giving intermediates 32 that can similarly produce tris-perfluoroalkanesulfonyl derivatives 33. These compounds are converted into the catalysts 34 by reaction with ytterbium oxide. It is shown that the highly fluorinated catalyst (34, Ri = C5F13, = C8F17) (10% mol)... 

Benzodithiolium perchlorate (218 R = H, X = CIO4) is highly explosive. Its 2-methylthio-derivative (218 R = MeS) condenses with 1-ethylaminonaphthalene to give the stable quinone-methide imine (219). Lithium trialkyl(alkynyl)borates Li R 3BC=CR (R R = n-CsHn or n-C6Hi3) react stereoselectively with the salt (218 R = H, X = Bp4) to produce vinylboranes (220) in high cis itrans ratios, which on hydrolysis and... 

Lithium tris(phenylthio)methide. Ipso anion precursor. Nuck... 

Nitrogen Systems.—Monoaza-compounds. Treatment of the azapentalene anion (745) with dichloromethane and butyl-lithium yields a mixture of indolizine (746 R = H) and compound (747) it has been established that the latter is not a precursor of indolizine.3-Diethylaminoindolizine (746 R = NEt2) is formed by the reaction of 2-bromopyridine with propargyl alcohol and diethylamine in the presence of bis(triphenylphosphine)palladium(ll) dichloride and copper(i) iodide. The pyridinium ylide (748) undergoes 1,5-dipolar cyclization to the tran -dihydroindolizine (749). As in previous years, there have been several reports on the synthesis of the indolizine ring system from pyridinium ylides the methide (750 R = H, R = Ph) adds benzylideneacetophenone to form the tetrahydroindolizine (751), the action of phenyl vinyl sulphoxide. 

Lithium tris(perfluoroaIkanesulfonyl)methide salts have also received some attention for battery electrolytes, especially the salt with the C(S02CF3)3 anion (TriTFSM ) (Figs. 1.22J and 1.23b). The experimental gas-phase acidity values... 

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