Aryl iodine-magnesium exchange

Functionalized aryl Grignard compounds, prepared by iodine-magnesium exchange according to the procedure reported by Cahiez, Knochel and coworkers in 1998, can be efficiently acylated. It is thus possible to prepare various polyfunctionalized diaryl ketones (Scheme 14). ... 

The chemistry of organomagnesium ate complexes TABLE 6. Iodine-magnesium exchange of aryl iodides... 

Substituted pyridines, quinolines, and diazines react with polyfunctionalized aryl Grignard reagents, obtained by iodine-magnesium exchange under very mild conditions in the presence of PdCl2(dppf) as a catalyst (Scheme 48). 136,137... 

Reaction of aryl Grignard compounds, obtained in situ by iodine-magnesium exchange, with C0CI2, presumably generates aryl radicals. In the presence of a double bond or aromatic ring an intramolecular radical cyclization may take place. This reaction was used for the synthesis of spiro-indolines.244 Oshima has applied cobalt-mediated tandem radical cyclization-cross-coupling reaction for the synthesis of benzyl-substituted heterocycles (Scheme 80).245... 

A convenient synthesis of aryl glycines from Grignard reagents, prepared via iodine-magnesium exchange, was performed by the reaction with N-Boc-iminomalonate (from diethyl mesoxalate and BocN=PPh3). The reaction... 

Iodine-magnesium exchange of aryl iodides bearing a functional group proceeds at low temperatures to provide the corresponding arylmagneslum compounds, which react with electrophiles [121]. Some examples are shown in Tab. 3.9. 

The iodine-magnesium exchange of aryl iodides with "Bu3MgLi, which is prepared by mixing "BuMgBr and "BuLi in a 1 2 ratio in THF at O C, proceeds smoothly at 0°C or -78 °C within 0.5 h, and the resulting arylmagnesium species are trapped by electrophiles. Examples are shown in Tab. 3.12. 

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