Alkali metals and derivatives

S.5.4. from Organogermanium Hydrides with Alkali Metals and Derivatives. 

Derivatives of Antimony Pentabromide and Pentaiodide. The existence of SbBr and Sbl is in doubt, although from time to time they are reported in the Hterature (35). The existence of a 1 1 adduct, SbBr 0(0244 )2, however, is generally accepted. In addition, the SbBr ion is known, and from x-ray studies has been found to have a slightly distorted octahedral stmcture (36). Indeed, there are quite a number of complex bromoantimony compounds with alkali metals and organic bases, some of wliich contain Sb(V). Thus the quinuclidinium salt (C24423N44)4Sb2Br2g is actually made up of... 

The alkynylation of estrone methyl ether with the lithium, sodium and potassium derivatives of propargyl alcohol, 3-butyn-l-ol, and propargyl aldehyde diethyl acetal in pyridine and dioxane has been studied by Miller. Every combination of alkali metal and alkyne tried, but one, gives the 17a-alkylated products (65a), (65c) and (65d). The exception is alkynylation with the potassium derivative of propargyl aldehyde diethyl acetal in pyridine at room temperature, which produces a mixture of epimeric 17-(3, 3 -diethoxy-T-propynyl) derivatives. The rate of alkynylation of estrone methyl ether depends on the structure of the alkyne and proceeds in the order propar-gylaldehyde diethyl acetal > 3-butyn-l-ol > propargyl alcohol. The reactivity of the alkali metal salts is in the order potassium > sodium > lithium. 

In the meantime, we believe that the best prediction of the toxicity of an ionic liquid of type [cation] [anion] can be derived from the often well known toxicity data for the salts [cation]Cl and Na[anion]. Since almost all chemistry in nature takes place in aqueous media, the ions of the ionic liquid can be assumed to be present in dissociated form. Therefore, a reliable prediction of ionic liquids HSE data should be possible from a combination of the loiown effects of the alkali metal and chloride salts. Already from these, very preliminary, studies, it is clear that HSE considerations will be an important criterion in selection and exclusion of specific ionic liquid candidates for future large-scale, technical applications. 

The simplest (and smallest) alkali metal alkynyl derivative, ethynyllithium, can only be obtained in the form of single crystals as a base adduct. In the presence of ethylenediamine (en), a polymeric compound as double strands connected by the en donors is obtained, 150.159... 

ACID ANHYDRIDES, ACYL HALIDES, ALKALI METALS ALKYLALUMINIUM DERIVATIVES, ALKYLNON-METAL HALIDES COMPLEX HYDRIDES, METAL HALIDES, METAL HYDRIDES METAL OXIDES, NON-METAL HALIDES (AND THEIR OXIDES)... 

Bipyridine is likewise reduced to 4,4 -bipiperidine by sodium and amyl alcohol and by catalytic hydrogenation. " 2,2 -Dimethyl-4,4 -bipyridine is reduced to 2,2 -dimethyl-4,4 -bipiperidine. Electrochemical reduction of 4,4 -bipyridine affords 4,4 -bipiperidine and some partly reduced 4,4 -bipyridines. Further work on the electroreduction of 4,4 -bipyridine has been reported. Reduction of 4,4 -bipyridine by tin and hydrochloric acid " or by controlled catalytic hydrogenation - gives l,2,3,4,5,6-hexahydro-4,4 -bipyridine. 4,4 -Bipyridine is reduced to its 1,4-dihydro derivative by bisdihydropyridyl metal complexes and to its radical anion by alkali metals and related processes. " " The ionization constant of the radical anion has been determined. ... 

The electrochemical oxidation of aromatic aldehydes (1) must be studied in strongly alkaline media. Acidity functions for strongly alkaline aqueous solutions of alkali metal and quaternary ammonium hydroxides, corresponding to dissociation of proton (H ), are well established (2, 3). Substituted anilines and diphenylamines (4,5) and indoles (6) were used as acid-base indicators for establishment of such scales, but whether an acidity scale based on one type of indicator can be rigorously applied to acid-base equilibria involving structurally different acidic groups for reactions in strongly alkaline media remains questionable. For substituted anilines, behavior both parallel (7) and nonparallel (8) to the H scale based on indole derivatives has been reported. The limited solubility of anilines in aqueous solutions of alkali metal hydroxides, the reactions of the aniline derivative with more than one hydroxide ion, irreversible substitution reactions (9), and the possibility of hydroxide ion addition rather than... 

Ring opening is common in the alkali metal and liquid ammonia reduction of furans unless an anion stabilizing group is present, so most work has been done with derivatives of furancarboxylic acids. Treatment of furan-2-carboxylic acid with lithium and ammonia at -78 °C followed by rapid addition of ammonium chloride affords 2,5-dihydrofuran-2-carboxylic acid (80%). Reductive alkylation similarly gives 2-alkyl-2,5-dihydrofuran-2-carboxylic acids. This method has been used in a synthesis of rosefuran, the intermediate dihydrofuran (66) being converted into the product (67) by oxidative decarboxylation with... 

Reactions with Alkali Metals and Their Derivatives... 

Several alkali metal (M) derived ate complexes have been prepared (Table 8). Again, the formation of such ternary systems is preferred. Even Sm(II) derivatives were readily available [89], A common feature of the observed molecular structures are close inter- and intramolecular M - C as well as close Ln-- Si van der Waals contacts which ensure steric saturation of the metal centers. Depending on the size of the alkali metal, different types of solid state structures are generated (Fig. 15). A comparison to the ammonia derived species in Sect. 2.1 can be drawn. 

When TDAE (a liquid at room temperature) is added to C60 in solution, the resulting salt crystallizes as small particles, which can be removed by filtration. TDAE+Cg0 is a charge-transfer salt with a monoclinic structure, different from the high-symmetry cubic structures of pristine C60 and its alkali metal-intercalated derivatives [83]. 

The second part of the chapter deals with several kinds of asymmetric reactions catalyzed by unique heterobimetallic complexes. These reagents are lanthanoid-alkali metal hybrids which form BINOL derivative complexes (LnMB, where Ln = lanthanoid, M = alkali metal, and B = BINOL derivative). These complexes efficiently promote asymmetric aldol-type reactions as well as asymmetric hydrophosphonylations of aldehydes (catalyzed by LnLB, where L = lithium), asymmetric Michael reactions (catalyzed by LnSB, where S = sodium), and asymmetric hydrophosphonylations of imines (catalyzed by LnPB, where P = potassium) to give the corresponding desired products in up to 98% ee. Spectroscopic analysis and computer simulations of these asymmetric reactions have revealed the synergistic cooperation of the two different metals in the complexes. These complexes are believed to function as both Brpnsted bases and as Lewis acids may prove to be applicable to a variety of new asymmetric catalytic reactions.1,2... 

---