Showing papers by "Constantinos G. Screttas published in 1987"

Radical anions in hydrocarbon media. Interaction between unsolvated and/or solvated radical anions and metal alkoxides. Evidence for cation dependent clustering of ketyl anions at high concentrations

Abstract: The reaction of benzophenone (I), stilbene (IV), and anthracene with the Li alkoxide (II) and alkali metals to yield radical anions is studied.

Formation of Ketones in the Reaction of Aldehydes with Unsolvated Dibutylmagnesium in Hydrocarbon Solvents Under Homogeneous Conditions, and Its Implications.

Abstract: Unsolvated dibutylmagnesium reacts with aldehydes in the presence of lithium alkoxide in methylcyclohexane to give not only the expected secondary alcohol but also the ketone formed by oxidation of the alcohol. The amount of ketone produced depends on the reactant ratios, which can be chosen so that the ketone is the major product. The relevance of these observations to the reactions of aldehydes with organomagnesium and organolithium reagents in general is discussed.

Hexane-Soluble Complexes of Alkyl- and Alkenyl-Sodium Compounds with Magnesium Alkoxides.

Abstract: Summary Unsolvated alkylsodium compounds are solubilized in hexane or methylcyclohexane by complexation with magnesium 2-ethoxyethoxide. The soluble species appear to have well defined stoichiometries, characterized by the Na/Mg ratio. Thus butylsodium forms a 2/1 complex which is of moderate thermal stability, but if sufficient magnesium alkoxide is added to the 2/1 complex to make the Na/Mg ratio 1/1, than the complex becomes thermally very stable. Both of the BuNa complexes exhibit normal organometallic reactivity toward CO2, but with benzophenone the main product is the reduction rather than the addition product. The pronounced reducing ability is also manifested by the reduction of transtion metal salts to either the metallic state (e.g. AgNO3 CoCl2) or to a lower valency state (e.g. TiCl4). The BuNa complexes react very rapidly with potassium metal and undergo sodium metal displacement. Alkenylsodiums derived by metalation of olefins may also form soluble complexes with magnesium 2-ethoxyethoxide.