This step is the most essential one to the successful preparation of the Grignard reagent
. A few drops of THF and the reminder of the total volume of paramethoxy bromo benzene were added from the dripping funnels, dropwise, to the mixture and temperature remained controlled (35-40[degrees]C).
2,5Dibromo-3-hexylthiophene was readily prepared by a literature procedure: coupling of n-hexyl Grignard reagent
with 3-bromothiophene in the presence of Ni(dppe)[Cl.sub.2], followed by bromination with NBS  Scheme 2).
The substitution of fluorine with an ethynyl anion can be accomplished by using a lithium organometallic reagent, Scheme 2, or a Grignard reagent
, Scheme 3.
For example, in the reaction of methyl benzoate and three equivalents of isopropyl Grignard reagent
, the desired diaklylated adduct yield was 32%.
The monosolvated Grignard reagent
in toluene is particularly liable to complexation with a silane.
The symmetrical derivatives were prepared from the corresponding Grignard reagent
A long-standing problem associated with Grignard reagent
synthesis is that, in order to facilitate reaction between the organic halide and the metal in an ether solvent, all of the reagents must be dry and the surface of the magnesium must be clean and oxide free.
Such [Cp'MO(NO)[X.sub.2] anions also result when the neutral precursors are treated with an equimolar amount of a Grignard reagent
[Figure 3(b)], thereby indicating the occurrence of at least some single-electron transfer during these latter reactions.
A yellow reaction mixture was formed called Grignard reagent
. To this freshly prepared Grignard's reagent, continuous supply of carbon dioxide was made using tubing and was allowed to bubble through the reaction mixture for a few minutes.
and Transition Metal Catalysts: Formation of C-C Bonds by Cross-Coupling
Among the topics are solid-phase reactions of polymer-bound arenesulfonates with aryl Grignard reagents
, resin-to-resin transfer reactions through Sonogashira coupling, polyaniline-immobilized palladium for Suzuki-Miyuaura coupling reactions in water, solid-phase reactions of resin-supported boronic acids, and the palladium-catalyzed solid-phase synthesis of allelic amines.