Methyl-2- iodo benzoate

Several solid supports have been employed for the attachment of o-iodosobenzoic acid, including silica gel, titania and nylon [89]. Two polymer-supported o-iodoxybenzoic acid reagents have recently been reported. The first was obtained by attaching a carboxymethyloxy derivative of f-butyl o-iodo-benzoate to an aminopropylated silica gel and oxidation with oxone [90]. The second involved chloromethylated polystyrene which was coupled with methyl 5-hydroxy-2-iodobenzoate and eventually oxidized by Bu4NS05H/MeS03H [91]. Some of these polymeric reagents appear in Scheme 31. 

Pans-2-Iodocyclohexyl acetate can be isolated in essentially quantitative yield from the reaction of thallium(I) acetate, iodine, and cyclohexene in a 1 1 1 molar ratio in refluxing chloroform. lodo acetates from a representative series of alkenes including cyclohexene have been similarly prepared in 80-98% yield in glacial acetic acid which was not dried as described in this procedure. The corresponding iodo benzoates are obtained in comparable yields from reaction with thallium(I) benzoate and iodine in benzene. The deactivated olefin methyl cinnamate did not react under these conditions, and o-allylphenol underwent ring iodination to... 

Methyl-2-iodoxybenzoate can be further converted to the diacetate 243 or a similar bis(trifluoroacetate) by treatment with acetic anhydride or trifluoroacetic anhydride, respectively (2005JOC6484). A single-crystal X-ray diffraction analysis of methyl-2-[(diacetoxy)(oxo)iodo]benzoate 243 revealed a pseudo-benziodoxole structure with three relatively weak intramolecular I 0 interactions. Esters of 2-iodoxyisophthalic acid (e.g., 244) were prepared by the oxidation of the respective iodoarenes with dimethyl-dioxirane. An X-ray structural analysis of diisopropyl 2-iodoxyisophthalate 244 has demonstrated strong intramolecular interaction with the... 

Barluenga et al.565 have reported the selective monoiodination of arenes with bis (pyridine)iodonium(I) tetrafluoroborate [I(py2)BF4] in excess superacids (2 equiv.) [Eq. (5.210)]. Comparable results were found for activated compounds with both HBF4 and triflic acid, whereas triflic acid was more effective in the iodination of deactivated aromatics. For example, nitrobenzene and methyl benzoate are unreactive in HBF4 but give the corresponding iodo derivatives in triflic acid (83% and 84% yields, respectively, in 14 h). Iodination of phenol required low temperature (-60°C). 

This reaction type differs from die three-component reaction reported by Grigg et al. Thus, Grigg et al. [53] (Scheme 7) immobihzed 3-iodo-4-(N-acetyl-N-(2-methyl-2-propenyl)amino)benzoate (36) onto a sohd support. In the presence of suitable Pd salts, Pd substituted the iodide function of the aromatic. The proximal isopropyhdene group trapped the resulting metalated species in an intramolecular Heck reaction. The resulting alkyl palladium species (37) could then react with a suitable carbanion equivalent. The authors used vinylstaimanes or boronates for this purpose, which they obtained in situ from alkynes by hydroboration or hydro-starmylation. The latter procedure allowed them to attach the same vinylic species via its terminal carbon (boronate) (41) and its subterminal carbon (stannane) (39). 

Palladium(II) acetate micro-encapsulated in polyurea is an economical and versatile heterogeneous catalyst for a range of phosphine-free cross-coupling reactions in both conventional solvents and supercritical carbon dioxide. The catalyst can be recovered by simple filtration and recycled up to four times [93]. The potential of these materials has been demonstrated by their efficacy in Suzuld-type couplings. Investigations have centered upon carbonylation reactions to prepare aryl esters from commercially available aryl iodides. Treatment of iodo-methyl benzene tvith 3 mol% of catalyst in butanol and triethylamine at 90 °C under an atmosphere of carbon monoxide afforded butyl-methyl benzoate in an excellent yield of 89% in 16 h. 

Methyl benzoate is formed from the 4-ethyl-4-iodo-l-methyl-l//-l,2,4-triazole-catalysed aerobic oxidation of benzaldehyde in THE in the presence of 1,8-diazabycyclo[5.4.0]undec-7-ene (DBU) and methanol. Benzoic acid is the oxidation product if the reaction is performed in the presence of water instead of the alcohol. These reactions are not reconciled with either oxidative or oxygenative mechanism... 

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