Alkali metal amides potassium

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... 

Alkali metals, particularly potassium 2. Alkali metal alkoxides and amides 3. Organometallics ... 

Alkali metals, especially potassium, rubidium, and cesium Metal amides (e.g., NaNH2)... 

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. 

Whereas an elimination-addition mechanism is not involved in the reaction of pyridines with alkali-metal amides, the reaction of potassium amide with 2-chloropyridine iV-oxide probably involves the intervention of 2,3-dehydropyridine N-oxide.3686 3,4-Dehydropyridine N-oxide is an intermediate in the reaction of 3-chloropyridine N-oxide with piperidine.388 ... 

Other pyridine derivatives have been aminated with alkali metal amides. Treatment of 2,3 -bipyridine (116) with sodium amide afforded the isomers shown in Scheme 46 (77MI1). In a similar fashion, 2,2 -bipyridine gave 6,6 -diamino-2,2 -bipyridine, 3,3 -bipyridine yielded 6-amino-3,3 -bipyridine, and 4,4 -bipyridine afforded 2,2 -diamino-4,4 -bipyridine upon treatment with sodium amide (78RCR1042). The amination of 2-chloro-5-nitropyridine gave the Chichibabin products 2-amino-6-chloro-3-nitropyridine and 4-amino-2-chloro-5-nitropyridine in low yields (<3% of each) on treatment with potassium amide in liquid ammonia. The main product was 2-amino-5-nitropyridine, obtained primarily by the S fANRORC) mechanism (85JOC484). 

Introduction. Potassium f-butoxide is intermediate in power among the bases which are commonly employed in modem organic synthesis. It is a stronger base than the alkali metal hydroxides and primary and secondary alkali metal alkoxides, but it is a weaker base than the alkali metal amides and their alkyl derivatives, e.g. the versatile strong base Lithium Diisopropylamide. ... 

Synthetically important alkali—metal amides Lithium, sodium, and potassium hexamethyldisilazides, diisopropylamides, and tetramethylpiper-idides 13AG(E)11470. 

One of the first solvent-free alkali metal amides to be investigated was potassium diethylamide, 149 [122]. In the solid state, rings of (KNEt2)2 units form a complicated network. An interesting ladder strueture containing amide bridges and n-coordination was found for sodium 2,3,4,5-tetramethylpyrrolide, 150 [123]. 

Elimination of the proton from 1, 4-diene or 1, 3-diene compounds is often used for the preparation of metal dienyl complexes. The following compounds are utilized as deprotonating reagents alkyllithium compounds, (trimethylsilylmethyl )potassium, alkali metal amides, etc. Also useful are alkali metals as sands in the presence of triethylamine, which prevents anionic polymerization of dienes. 

Alkali metal amides cannot generally be prepared by direct reduction of the N-H bond. An exception is the rapid attack of potassium by 1,3-propanediamine, but catalytic amounts of ferric nitrate are necessary.i47 resulting strong base. 

A number of compounds of the types RBiY2 or R2BiY, where Y is an anionic group other than halogen, have been prepared by the reaction of a dihalo- or halobismuthine with a lithium, sodium, potassium, ammonium, silver, or lead alkoxide (120,121), amide (122,123), a2ide (124,125), carboxylate (121,126), cyanide (125,127), dithiocarbamate (128,129), mercaptide (130,131), nitrate (108), phenoxide (120), selenocyanate (125), silanolate (132), thiocyanate (125,127), or xanthate (133). Dialkyl- and diaryUialobismuthines can also be readily converted to secondary bismuthides by treatment with an alkali metal (50,105,134) ... 

Primary aromatic amides are crystalline solids with definite melting points. Upon boiling with 10-20 per cent, sodium or potassium hydroxide solution, they are hydrolysed with the evolution of ammonia (vapour turns red litmus paper blue and mercurous nitrate paper black) and the formation of the alkali metal salt of the acid ... 

To test this approach, 5 g samples -300 mesh Tyler, of a low-rank vitrinite, were stirred for 6 hrs in liquid ammonia (150 ml -33°C) containing 5 gms of potassium amide and 5 g of sodium amide. (The amides were formed in the medium, before introducing the coal, by action of anhydrous ferric oxide (1 g) or ferric chloride (1.5 g) on alkali metals.) Thereafter, 100 ml of anhydrous ethyl ether was added, the suspended coal material ethylated with C2H5Br (32 ml), and the reaction mixture stirred until all ammonia and ether had evaporated. Following... 

At the outset of our studies of the reactivity of I and II, it was necessary to investigate claims that tertiary henzamides were inappropriate substrates for the Birch reduction. It had been reported that reduction of A,A-dimethylbenzamide with sodium in NH3 in the presence of tert-butyl alcohol gave benzaldehyde and a benzaldehyde-ammonia adduct. We formd that the competition between reduction of the amide group and the aromatic ring was strongly dependent on reaction variables, such as the alkali metal (type and quantity), the availability of a proton source more acidic than NH3, and reaction temperature. Reduction with potassium in NH3-THF solution at —78 °C in the presence of 1 equiv. of tert-butyl alcohol gave the cyclohexa-1,4-diene 2 in 92% isolated yield (Scheme 3). At the other extreme, reduction with lithium in NH3-THF at —33 °C in the absence of tert-butyl alcohol gave benzaldehyde and benzyl alcohol as major reaction products. ... 

Ruthenium(III) catalyses the oxidative decarboxylation of butanoic and 2-methylpropanoic acid in aqueous sulfuric acid. ° Studies of alkaline earth (Ba, Sr) metal alkoxides in amide ethanolysis and of alkali metal alkoxide clusters as highly effective transesterification catalysts were covered earlier. Kinetic studies of the ethanolysis of 5-nitroquinol-8-yl benzoate (228) in the presence of lithium, sodium, or potassium ethoxide revealed that the highest catalytic activity is observed with Na+.iio... 

These catalysts require temperatures above 100° and usually 150-200° for reasonable rates. Alkylsodium compounds at their decomposition temperatures (50-90°) have also been used by Pines and Haag (9). Lithium reacted with ethylene diamine has also been reported by Reggel et al. (4) as a catalyst for this reaction. The homogeneous system thus formed seems to lower the temperature requirement to 100° (4), whereas the use of potassium amide in liquid ammonia requires 120° (S). Sodium reacted with ethylene diamine has been reported to be an ineffective catalyst (4)- The most active catalyst systems reported so far are high-surface alkali metals and activated-alumina supports. They are very effective at or near room temperature (10-12). 

Electron-transfer initiation from other radical-anions, such as those formed by reaction of sodium with nonenolizable ketones, azomthines, nitriles, azo and azoxy compounds, has also been studied. In addition to radical-anions, initiation by electron transfer has been observed when one uses certain alkali metals in liquid ammonia. Polymerizations initiated by alkali metals in liquid ammonia proceed by two different mechanisms. In some systems, such as the polymerizations of styrene and methacrylonitrile by potassium, the initiation is due to amide ion formed in the system [Overberger et al., I960]. Such polymerizations are analogous to those initiated by alkali amides. Polymerization in other systems cannot be due to amide ion. Thus, polymerization of methacrylonitrile by lithium in liquid ammonia proceeds at a much faster rate than that initiated by lithium amide in liquid ammonia [Overberger et al., 1959]. The mechanism of polymerization is considered to involve the formation of a solvated electron ... 

Some acetylenic (with a non-terminal triple bond) or allenic compounds, RCH=C CH2, can be transformed into alkali metal derivatives of terminal acetylenes by treatment with a very strong base. Treatment of an acetylenic compound with the grouping CHjCsC- or CH3C=CCH=CH- with one equivalent of an alkali amide (preferably the soluble potassium... 

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