Lithium bromide iodide

Lithium bromide and iodide probably have some degree of covalenc> but this does not affect the general conclusion. 

DTGS = deuterated triglycine sulfate KRS — 5 = mixed thallium bromide-iodide LT = lithium tantalate MCT = mercury cadmium telluride and OPO = optical parametric oscillator. 

Although ethereal solutions of methyl lithium may be prepared by the reaction of lithium wire with either methyl iodide or methyl bromide in ether solution, the molar equivalent of lithium iodide or lithium bromide formed in these reactions remains in solution and forms, in part, a complex with the methyllithium. Certain of the ethereal solutions of methyl 1ithium currently marketed by several suppliers including Alfa Products, Morton/Thiokol, Inc., Aldrich Chemical Company, and Lithium Corporation of America, Inc., have been prepared from methyl bromide and contain a full molar equivalent of lithium bromide. In several applications such as the use of methyllithium to prepare lithium dimethyl cuprate or the use of methyllithium in 1,2-dimethyoxyethane to prepare lithium enolates from enol acetates or triraethyl silyl enol ethers, the presence of this lithium salt interferes with the titration and use of methyllithium. There is also evidence which indicates that the stereochemistry observed during addition of methyllithium to carbonyl compounds may be influenced significantly by the presence of a lithium salt in the reaction solution. For these reasons it is often desirable to have ethereal solutions... 

Metal halide salts other than sodium iodide have been used sparsely to prepare halodeoxy sugars from sulfonate esters. Lithium chloride (107) and lithium bromide (33) have found limited application. Potassium fluoride (dihydrate) in absolute methanol has been used (51, 52) to introduce fluorine atoms in terminal positions of various D-glucose derivatives. The reaction is conducted in sealed tube systems and requires... 

Another variation of this method involves the treatment of an acetonitrile solution of the aryl aldehyde, trimethylsilyl chloride, and either sodium iodide, if iodide products are desired, or lithium bromide, if bromide products are desired, with TMDO. After an appropriate reaction time (5-195 minutes) at a temperature in the range of —70° to 80°, the upper siloxane layer is removed and the benzyl iodide or bromide product is isolated from the remaining lower portion after precipitation of the inorganic salts by addition of dichloromethane. For example, p-anisaldehyde reacts to form /i-rnethoxybenzyl bromide in 84% isolated yield under these conditions (Eq. 200).314,356... 

The testing of a rigid-sphere approximation must however be logically consistent, and if the anions are big enough they must be in anion-anion contact. The geometry of this is well-known (7) from the halide-radii just obtained from potassium salts, the anions should be in contact in lithium bromide and iodide conversely from their experimental anion-anion distances one would infer for r ... 

Lithium alkynyl(trialkoxy)borates have also been found suitable partners for this reaction, and have been success-fully coupled with aryl bromides, iodides, and allyl carbonates. Molander recently reported on the coupling of alkynyltrifluoroborates with aryl bromides, triflates, and chlorides in moderate yields using Pd(dppf)Gl2 as catalyst and GS2GO3 as base, in THF or water at 60... 

In agreement with this mechanism, it was found that the epoxide (4RS)-4,4-(epoxy-methano)tricyclo[5.1.0.02,5]octane-e c/o-8-carbaldehyde 2,2-dimethylpropaneT,3-diyl acetal (1) gave 4-oxotricyclo[6.1.0.02,6]nonane- ,/ttreatment with lithium iodide in tetrahydrofuran.71 Several examples employing this oxaspirohexane to cyclopentanone isomerization method are shown (see Table 7).69-80 Lithium bromide in the presence of hexamethylphosphoric triamide was also effective in these transformations.70,74,76 79,80... 

The chlorides, bromides, iodides, and cyanides are generally vigorously attacked by fluorine in the cold sulphides, nitrides, and phosphides are attacked in the cold or may be when warmed a little the oxides of the alkalies and alkaline earths are vigorously attacked with incandescence the other oxides usually require to be warmed. The sulphates usually require warming the nitrates generally resist attack even when warmed. The phosphates are more easily attacked than the sulphates. The carbonates of sodium, lithium, calcium, and lead are decomposed at ordinary temp, with incandescence, but potassium carbonate is not decomposed even at a dull red heat. Fluorine does not act on sodium bofate. Most of these reactions have been qualitatively studied by H. Moissan,15 and described in his monograph, Lefluor et ses composes (Paris, 1900). 

Aq. soln. of lithium chloride absorb larger amounts of ammonia than water alone, owing to the formation of complexes, LiCl(NH3) —lithium ammino-chlorides. Similar remarks apply to lithium bromide and iodide. If the solubility of ammonia in water be unity, R. Abegg and H. Riesenfeld found the solubility at 25° is ... 

H. Stamm also measured the solubilities of the salts of the alkalies in liquid ammonia —potassium hydroxide, nitrate, sulphate, chromate, oxalate, perchlorate, persulphate, chloride, bromide, iodide, carbonate, and chlorate rubidium chloride, bromide, and sulphate esesium chloride, iodide, carbonate, and sulphate lithium chloride and sulphate sodium phosphate, phosphite, hypophosphite, fluoride, chloride, iodide, bromate, perchlorate, periodate, hyponitrire, nitrite, nitrate, azide, dithionate, chromate, carbonate, oxalate, benzoate, phtnalate, isophthalate ammonium, chloride, chlorate, bromide, iodide, perchlorate, sulphate, sulphite, chromate, molybdate, nitrate, dithionate, thiosulphate, persulphate, thiocyanate, phosphate, phosphite, hypophosphite, arsenate, arsenite, amidosulphonate, ferrocyanide, carbonate, benzoate, methionate, phenylacetate, picrate, salicylate, phenylpropionate, benzoldisulphonate, benzolsulphonate, phthalate, trimesmate, mellitate, aliphatic dicarboxylates, tartrate, fumarate, and maleinate and phenol. 

Alternatively, a more nucleophilic anionic reagent can be generated by selective cleavage of a single trimethylsilyl group with methyl lithium-lithium bromide complex. This 1ithiobutadlyne derivative will react with electrophiles such as carbonyl compounds or primary alkyl iodides. 2... 

Primary and secondary alkyl bromides, iodides, and sulfonates can be reduced to the corresponding alkanes with LiBHEt3 (superhydride) or with lithium aluminum hydride (LiAlH4, other names lithium tetrahydridoaluminate or lithium alanate). If such a reaction occurs at a stereocenter, the reaction proceeds with substantial or often even complete stereoselectivity via backside attack by the hydride transfer reagent. The reduction of alkyl chlorides to alkanes is much easier with superhydride than with LiAlH4. The same is true for sterically hindered halides and sulfonates ... 

The following 1,2-oxatellurolium iodides were similarly prepared using sodium iodide instead of lithium bromide and stirring the mixture for 15 min at 50o1. 

While the major use for palladium catalysis is to make carbon-carbon bonds, which are difficult to make using conventional reactions, the success of this approach has recently led to its application to forming carbon-heteroatom bonds as well. The Overall result is a nucleophilic substitution at a vinylic or aromatic centre, which would not normally be possible. A range of aromatic amines can be prepared direcdy from the corresponding bromides, iodides, or triflates and the required amine in the presence of palladium(O) and a strong alkoxide base. Similarly, lithium thiolates couple with vinylic triflates to give vinyl sulfides provided lithium chloride is present. 

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