Carbon nucleophiles aryl iodide

Arylation or alkenylation of soft carbon nucleophiles such as malonate is carried out by using a copper catalyst, but it is not a smooth reaction. The reaction of malononitrile, cyanoacetate, and phenylsulfonylacetonitrile with aryl iodide is possible by using a Pd catalyst to give the coupling products. 

The coupling of aryl halides and classical carbon nucleophiles, such as malonates, is also feasible in the presence of a properly selected palladium or copper catalyst. Diethyl malonate and 3-iodopyridine, for example, gave diethyl 2-(3 -pyridyl)malonate in 73% yield (7.84.), The optimal catalyst in this process consisted of copper(I) iodide and 2-hydroxylbiphenyl.106... 

More reactive carbon nucleophiles than enolates can also be prepared on insoluble supports (see Chapter 4) and are used to convert aldehydes or ketones into alcohols. Organolithium compounds have been generated on cross-linked polystyrene by deprotonation of formamidines and by metallation of aryl iodides (Table 7.5). Similarly, support-bound organomagnesium compounds can be prepared by metallation of aryl and vinyl iodides with Grignard reagents. The resulting organometallic compounds react with aldehydes or ketones to yield the expected alcohols (Table 7.5). 

Palladium(0)-catalysed coupling of non-conjugated dienes, aryl iodides and stabilized carbon nucleophiles has been developed468. An incredibly high yield (86%) of pentacycle 343 has been obtained from a Pd(0)-catalysed zipper reaction of acetylenic pentaene 342. The reaction is triggered off by a Pd-catalysed cyclization of acetylenic bond and the first olefinic bond469. 

During arylations of carbon nucleophiles with aryl halides in the presence of palladium triarylphosphine complexes products containing the aryl group of the phosphine can result (Scheme8.16). These reactions proceed via reversible arylation of the Pd-bound phosphine, which occurs at temperatures above 50 °C, particularly readily in the presence of iodide [11] (see Section 8.2). Electron-deficient aryl groups usually migrate less readily than electron-rich groups [23, 25],... 

Related reactions of nonconjugated dienes (e.g., 1,4-dienes) underwent a similar coupling reaction with aryl iodides and stabilized carbon nucleophiles [43]. In this reaction, the... 

Arylcyclopropanes are obtained from coupling using cyclopropylzinc halides. Carbonylative coupttng. Symmetrical ketones are formed on treatment of organozinc reagents with (PhjPl Pd under CO. In the presence of aryl iodides the reaction with RZnI gives RCOAr. Methacrylic acid derivatives are formed by a Pd-catalyzed reaction of allene, carbon monoxide, and nucleophiles. ... 

Larock, R.C., Lu, Y.-d., Bain, A.C. and Russell, C.E. (1991) Palladium-catalyzed coupling of aryl iodides, nonconjugated dienes and carbon nucleophiles by palladium migration. J. Org. Chem., 56,4589-90. 

The carbonylation of aryl halides in the presence of suitable nucleophiles such as alcohols and amines offers an attractive approach to benzoic acid derivatives. Hence, the reaction of polymer-supported primary and secondary alcohols with aryl iodides under a carbon monoxide atmosphere was investigated. Under the reported reaction conditions, this three-component reaction proceeded in good yields and after cleavage the products were obtained in moderate to good purities (Scheme 27). ... 

A synthesis of tylophorine 6.207 used an electron-rich arene as the carbon nucleophile (Scheme 6.92). The substrate was constructed by a sequence of two Suzuki couplings (Section 2.6), first an aryl-aryl coupling between iodide 6.201 and boronic acid 6.202, then an aryl-alkyne coupling, using an alkyne boronate 6.204 derived from proline. Platinum-catalysed cyclization generated the pyrrolidine 6.206, and the synthesis was completed by a one-pot deprotection-Pictet-Spengler reaction. 

Nucleophilic Displacement. PhTMS-BF3 0Et2 system has been shown to be useful in the transformation of allylic alcohols to allylic sulfides (eq IS). Preparation of unsymmetrical diaryl sulfides can be achieved by reaction of arenediazonium tetraflu-oroborates with PhSTMS (eq 19). In some cases, addition of cupric sulfide increases the yield of the diaryl sulfides. The use of (phenylthio)trimethylsilane as a coupling partner in palladium catalyzed reactions with aUyl carbonates (eq 20) and aryl iodide (eq 21) has been explored. ... 

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