Metal groups aryl iodide

Reactivity and yields are greatly enhanced by the presence of 0.5-1% Na in the Li. The reaction is also generally available for the preparation of metal alkyls of the heavier Group 1 metals. Lithium aryls are best prepared by metal-halogen exchange using LiBu" and an aryl iodide, and transmetalation is the most convenient route to vinyl, allyl and other unsaturated derivatives ... 

This is a very rare metal in cross-coupling reactions. Direct comparison of similar methylating reagents derived from Al, Ga, and In showed that the Ga derivative is the least reactive.165 Vinylgallium dichlorides underwent cross-coupling with aryl iodides in the presence of Pd catalysts with P(o-tol)3 the reaction is moderately tolerant to acidic functional groups.166... 

This group is stable to metalation of the aromatic ring hy metal halogen exchange, Grignard formation, LiAlLL, reduction, NaOH, PDC, hydrogenolysis, NaBLL, and LDA. Reaction of an aromatic triazene with Mel at 120°C gives the aryl iodide. ... 

Substrate—Aromatic bromides or iodides (Ar-X) are rapidly converted to the corresponding aryllithium (Ar-Li) when treated with 1 molar equivalent of n-BuLi or 2 molar equivalents of (-BuLi. However, some substrates may rearrange to a more thermodynamically stable aryllithium via abstraction of a proton from a more acidic site, and this can lead to the formation of unwanted impurities (Scheme 12.5, eq. 2). Similarly, proton abstraction from aryl bromide substrates that contain an ortfto-directing metalation group (DMG) may lead to impurities in the final product. ... 

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