Multigram syntheses of magnesium(I) compounds using alkali metal halide supported alkali metals as dispersible reducing agents

The alkali metal halide supported alkali metal materials, ca. 5% w/w Na/NaCl and 5% w/w K/KI, are prepared without specialist equipment by rapidly stirring molten alkali metal with finely ground alkali metal halide powder. Scanning electron microscopy reveals the particles of 5% w/w Na/NaCl to lie largely in the 10-100 μM size range. The freely flowing powders are easily dispersible in organic solvents and are used as reducing agents for the facile syntheses of three magnesium(I) compounds, [{HC(MeCNAr)₂}Mg]₂, Ar = mesityl (Mes), 2,6-diethylphenyl (Dep), or 2,6-diisopropylphenyl (Dip), which can be obtained in yields of up to 12 g. The potential advantages Na/NaCl and K/KI powders offer to synthetic inorganic/organometallic chemists, relative to currently available alkali metal reducing agents, are discussed.