Activated metals. IV. Preparation and reactions of highly reactive magnesium metal

Abstract

The reduction of magnesium salts in ethereal solvents with potassium or sodium yields magnesium in the form of a fine black powder. This magnesium metal exhibits unusual reactivity toward alkyl and aryl halides. For example, bromobenzene reacts with the magnesium yielding phenylmagnesium bromide in a few minutes at -78". Rieke, Bales / Reactions of Highly Reactive Magnesium Metal

Preparation of fluorohalomethylmagnesium halides using highly active magnesium metal and their reactions

“…Rieke and co-workers published a series of methods resulting in the formation of highly active magnesium metal, which allowed the preparation of organomagnesium compounds at temperatures as low as À80 8C [16][17][18][19]. One using potassium and magnesium bromide worked best in our hands.…”

Chemistry of and with Highly Reactive Metals

“…To simplify workup of the reaction mixture the use of polymer-bound Rieke metals has also Tdbk 2. Effect of diverse additives o n the reactwiry of Rieke magnesium in the reaction with p-chlorotoluene at 0 C [20]. …”

Anionic block copolymerization of vinyl functionalized triphenylphosphines with styrene

“…4-Styryldiphenylphosphine (I) was synthesized by a published method that was modified to improve the yield 16,17) . Freshly cut potassium (19.93 g, 0.50 mol, 2.6 eq), water free magnesium chloride (24.28 g, 0.26 mol, 1.3 eq), dry potassium iodide (21.15 g, 0.13 mol, 0.65 eq) and THF (550 Scheme 1: mL) were placed in nitrogen atmosphere in a 1 L threenecked flask equipped with a condenser, a Stutz vacuum valve, a 100 mL addition funnel, thermometer, and magnetic stirring bar.…”

“…The use of activated magnesium for the preparation of the Grignard compound increased the yield from 32 to 88%. This might be due to the absence of thermal polymerization of the styrene derivative, as activated magnesium allows the reaction to be carried out at low temperature 17) . Polymerization: The homopolymerization of the 4-styryldiphenylphosphine monomer occurred in a very controlled manner.…”