Lithium-Alkylamines

The reduction of a carbon-carbon multiple bond by the use of a dissolving metal was first accomplished by Campbell and Eby in 1941. The reduction of disubstituted alkynes to c/ s-alkenes by catalytic hydrogenation, for example by the use of Raney nickel, provided an excellent method for the preparation of isomerically pure c -alkenes. At the time, however, there were no practical synthetic methods for the preparation of pure trani-alkenes. All of the previously existing procedures for the formation of an alkene resulted in the formation of mixtures of the cis- and trans-alkenes, which were extremely difficult to separate with the techniques existing at that time (basically fractional distillation) into the pure components. Campbell and Eby discovered that dialkylacetylenes could be reduced to pure frani-alkenes with sodium in liquid ammonia in good yields and in remarkable states of isomeric purity. Since that time several metal/solvent systems have been found useful for the reduction of C=C and C C bonds in alkenes and alkynes, including lithium/alkylamine, ° calcium/alkylamine, so-dium/HMPA in the absence or presence of a proton donor,activated zinc in the presence of a proton donor (an alcohol), and ytterbium in liquid ammonia. Although most of these reductions involve the reduction of an alkyne to an alkene, several very synthetically useful reactions involve the reduction of a,3-unsaturated ketones to saturated ketones. ... 

Ketene generator (K-1), 529 Lithium-alkylamine reduction (L-1), 580 Manipulation of a noxious solid with rubber gloves, a powder funnel, and a dust mask (N-3), 717 Mel-Temp apparatus (D-3), 243 Mercury seal for stirrer (G-3), 416 Model of the complex Coi(CO)g CuHaC— CCsHt (D-1) for construction of cobalt atoms, see L. F. Fieser, J- Chem. Ed., 42, 408 (1965), 111 Molecular sieve crystals (M-2), 704... 

N-lithioethylenediamine, 567-570 Lithium, 18, 570-573 alkyl and atyl derivatives, 571-573 Lithium acetylide, 573-574 Lithium acetylide-Ethylenediamine, 574 Lithium alkanyls, 280 Lithium-Alkylamine reduction, 137, 138, 574-581... 

Liebermann-Burchardt reaction, 137, 138 ( )-Lindestrene, 141 N-Lithioethylenediamine, 239 3-Lithio-l-trimethylsilylpropyne, 239-241 Lithium, 208, 255 Lithium acetylide, 241, 288 Lithium acetylide -ethylenediamine, 208 Lithium-Alkylamine reduction, 241-242 Lithium alkynes, 52... 

Lithio-1 -trimethylsilylpropyne, 638 Lithium, 274, 351 Lithium-Alkylamines, 322 Lithium-Ammonia, 322-323,463, 502 Lithium-Ethylamine, 12 Lithium-Hexamethylphosphoric triamide, 323... 

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