Alkali metals amide

The intervening years have seen huge growth in the number of well-characterized compounds, the vast majority of which are lithium, sodium or potassium salts. Their strucuiral chemistry has proven to be especially rich and the number of structures of alkali metal amides currently available exceeds 200. These involve a wide selection of structural motifs that were mostly unknown in 1980. 

There have been several reviews on alkali metal amide structural chemistry. Most of these deal with lithium amides but there is also significant coverage of the heavier elements and other topics such as derivatives of primary amides and hydrazides. Two comprehensive reviews for lithium amides and related salts published in 1991 and 1995 include extensive tables of structural data. There have also been reviews of the of lithium amides as well as of the extensive use of alkah metal 

Metal Amide Chemistry Michael Lappert, Andrey Protchenko, Philip Power and Alexandra Seeber 

Although lithium and sodium amide are commercially available, the suspensions prepared in liquid ammonia are much more reactive, and most reactions with these bases are carried out in this solvent. Lithium and sodium amide can be obtained in a dry state by completely evaporating the ammonia, the last traces in a water-pump vacuum. The powders obtained are very reactive and must be stored under 

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The conversion of acetylenes into acetyl ides, M-C=C-R (M = Li, Na, K, MgBr), by means of alkyllithium or Grignard reagents in organic solvents or by alkali metal amides in liquid ammonia is well documented (for practical examples see ref. 1, for review articles consult inter alia refs. 2-5). 

RCsC-H + C2H5U, Ci,HqLi or alkali metal amide ... 

Deprotonation of terminal acetylenes by organolithiurn compounds in organic solvents or by alkali metal amides is an extremely fast reaction, even at very... 

The last isomerization is remarkable in that the triple bond can shift through a long carbon chain to the terminus, where it is fixed as the (kinetically) stable acetylide. The reagent is a solution of potassium diami no-propyl amide in 1,3-di-aminopropane. In some cases alkali metal amides in liquid ammonia car also bring about "contra-thermodynamic" isomerizations the reactions are successful only if the triple bond is in the 2-position. 

This isomerization, which must proceed through a 1,2,3-trienylanine, is not "contra-thermodynamic", since with a catalytic amount of potassium tert.-butoxide the same result is obtained. Enyne ethers, H2C=CH-CsC-0R, undergo a similar conversion into HCeC-CH=CH-OR upon interaction with alkali metal amides in liquid NH3, followed by hydrolysis . Enyne sulphides, H2C=CH-CsC-SR, and the hydrocarbons H2C=CH-CsC-R (R = or phenyl) give only tars or polymeric products under... 

Organometallic reagents and alkali metal amides can react via a cyclic transition state (Section II, B, 5) beginning with electrophilic attack at the most basic ring-nitrogen. As a result, sodamide (in dimethylaniline, 145°, 2 hr) yields the 4-amino derivatives (40% yield S)) methyl- or phenyl-magnesium iodides give the 4-adduct quantitatively.s ... 

Pyridine and other heterocyclic nitrogen compounds can be aminated with alkali metal amides in a process called the Chichibabin reaction The attack is always in the 2 position unless both such positions are filled, in which case the 4 position is attacked. Substituted alkali metal amides (e.g., RNH and R2N ) have also been used. The mechanism is probably similar to that of 13-15. The existence of intermediate ions such as 15... 

Benzylic quaternary ammonium salts, when treated with alkali metal amides, undergo a rearrangement called the Sommelet-Hauser rearrangementSince the product is a benzylic tertiary amine, it can be further alkylated and the product again subjected to the rearrangement. This process can be continued around the ring until an ortho position is blocked. ... 

Alkali metal amides and Nitriles and ethylene diamines ... 

Alkali metal amides and hydrides C Liquid ammonia B... 

Interaction of selenium with alkali metal amides and alkaline earth metal amides gives explosive products. 

Reactions of amines with alkenes have been reviewed298,299. Alkali metal amides are active homogeneous catalysts for the amination of olefins. Thus diethylamine and ethylene yield triethylamine when heated at 70-90 °C at 6-10 atm in the presence of lithium diethylamide and /V./V./V. /V -tetrarncthylcthylcncdiaminc. Solutions of caesium amide promote the addition of ammonia to ethylene at 100 °C and 110 atm to give mixtures of mono-, di- and triethylamines300. The iridium(I)-catalysed addition of aniline to norbomene affords the anilinonorbomane 274301. Treatment of norbomene with aniline... 

Wittig rearrangement of benzylic quaternary ammonium salts upon treatment with alkali metal amides via the ammonium ylide intermediates. 

With alkali metal amides violent reactions occur, forming alkali hydroxides and ammonia ... 

Pyridine and other heterocyclic nitrogen compounds an be aminated with the alkali-metal amides by chichibabin reaction. The attack is always in the 2 position unless both such positions... 

Salts of very powerful oxidizing acids (eg chromic or permanganic) are unknown, and are unlikely to exist. Hydrazonium iodate may exist in solution at low temp (Ref 27a). Alkali metals, amides and hydrides react with hydrazine to give the corresponding alkali hydrazide. Sodium hydrazide explodes violently in the presence of 02 or when heated above 100°C—a typical behavior of the alkali hydrazides. For other reactions, see Ref 24 Explosive and Combustion Properties... 

For the anionic polymerization of methacrylonitrile (MAN), many initiators have been developed, which include alkali-metal alkyls such as butyllithium [42], triphenylmethylsodium [43], phenylisopropylpotassium [43], the disodium salt of living a-methylstyrene tetramer [44], alkali-metal amides [45], alkoxides [46], and hydroxide [47], alkali metal in liquid NH3 [48], quaternary ammonium hydroxide [49], and a silyl ketene acetal coupled with nucleophilic or Lewis acidic catalysts [50]. However, only a single example of the synthesis of PMAN with narrow molecular-weight distribution can be cited, and the reported number-average molecular weights were much higher than those calculated from the stoichiometry of the butyllithium initiator [42]. 

In a related manner, ketene S,N-acetals also react with alkali metal amides to give ynamines [19] (Eq. 30). Some examples are shown in Table V. 

Ynamines can also be produced by a or jS eliminations in the reaction of dihaloalkenes or trihaloalkenes with alkali metal amides [10,21] (Eqs. 26-29). 

Lithium amides are the most important of the alkali metal amides. This is mainly due to the facility with which they can be prepared in solution by the simple reaction of the amine with commercially available LiBu". An analogous reaction with heavier metal alkyls is much more difficult due to the high reactivity of heavier alkali metal alkyls which attack many solvents. Another advantage of lithium amides is that they tend to be more soluble in hydrocarbons than their heavier element congeners. This is due to the small size (and hence greater polarizing power) of the lithium ion, which induces greater covalent character. 

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