Lithium-Alkylamine reduction

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... 

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. ... 

In an attempt to prepare alkylamines by asymmetric reduction of imines with chiral hydride reagents, diphenylphosphinyl imines (38), prepared by reaction of ketoximes (39) with chlorodiphenylphosphine [(Cg 115)2 PCI], were reduced in the presence of a variety of chiral aluminum and boron hydride reagents43. Among the most promising reagents was BINAHL-H44 (40), a chiral hydride compound prepared by the modification of lithium... 

Reduction Nitriles and amides can be easily reduced to alkylamines using lithium aluminium hydride (LiAlH4). In the case of a nitrile, a primary amine is the only possible product. Primary, secondary, and tertiary amines can be prepared from primary, secondary and tertiary amides, respectively. 

Reduction ofarenes. Calcium in a mixed solvent composed of methylamine and cthylenediamine is comparable to lithium and an alkylamine for reduction of aromatic hydrocarbons to monoenes. Thus naphthalene is reduced by this newer system to A -octalin (82%) and A -octalin (18%). The method is more efficient than one using calcium and liquid ammonia, although the latter method is considerably improved in rate and selectivity by small amounts of HMPT. 

Alkylamines are generally accessible via the reduction of nitroalkenes with lithium aluminum hy-dride. Substituted thienylethylamines can also be obtained using this methodology (equation 30). 

One of die most popular reactions in organic chemistry is dissolving metal reductions [1-3], Two systems are frequently used - sodium dissolved in ammonia with alcohol and lithium dissolved in alkylamines [4]. Although calcium is seldom used, it has been successfully applied to the reduction of a variety of compounds and functional groups [5], including aromatic hydrocarbons, carbon-carbon double and triple bonds, benzyl ethers, allyl ethers, epoxides, esters, aliphatic nitriles, dithianes, als well as thiophenyl and sulfonyl groups. 

Reduction of aikyi azides (Section 22.10) Alkyl azides, prepared by nucleophilic substitution by azide ion in primary or secondary alkyl halides, are reduced to primary alkylamines by lithium aluminum hydride or by catalytic hydrogenation. 

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