5-phenyl- -iodide

Repeat this analysis for the reaction of phenyl methyl ether with HI leading to phenol and methyl iodide or methanol and phenyl iodide and involving protonated phenyl methyl ether as an intermediate. (Note In this case, the appropriate empty molecular orbital is LUMO+2 the LUMO is concentrated primarily on the CO bond.) Which reaction, with ethyl propyl ether or phenyl methyl ether, appears to be more likely to give selective ether cleavage ... 

Isoquinolinium, 2-ethyl 3,4-dihydro 6,7 dimethoxy-l-phenyl-, iodide (23581-03 51,7... 

Phenyl iodide chemisorbs dissociatively at a Cu(110) surface at 295 K with structural information being obtained from STM and chemical information from XPS.28 At low exposures (6 L), the surface concentrations of carbon and iodine species, calculated from the intensities of the C(ls) and I(3d) spectra, were in the expected 6 1 ratio and the iodine concentration 5.1 x 1014cm 2. With further exposure, the iodine concentration increased and reached a maximum value of 5.5 x 1014cm-2 after an exposure of 1200L. This was... 

Phenyl iodide dissociates at Cu(110) to form a c(2 x 2) iodine layer, accompanied by coupling of phenyl groups which desorb as biphenyl but with evidence that some phenyl groups remain at the surface stabilised as chains at step-edges and on terraces as paired chains . Chemisorption of HC1 at Cu(110) is corrosive , with evidence for surface buckling. 

Ternary Pd-catalyzed coupling reactions of bicyclic olefins (most often norbor-nadiene is used) with aryl and vinyl halides and various nucleophiles have been investigated intensively over the past few years [44]. A new approach in this field is to combine Heck and Suzuki reactions using a mixture of phenyliodide, phenyl-boronic acid and the norbornadiene dicarboxylate. Optimizing the conditions led to 84% of the desired biphenylnorbornene dicarboxylate [45]. Substituted phenyl-iodides and phenylboronic acids can also be used, though the variation at the norbornadiene moiety is highly limited. 

Highly reactive zinc can be prepared by reduction of anhydrous ZnC with potassium/THF or sodium/DME(l 7,29). This zinc has been shown to undergo rapid oxidative additions with alkyl bromides to produce near quantitative yields of the corresponding dialkylzinc. It also underwent oxidative addition with phenyl iodide and bromide. Moreover, the zinc was found to be useful in the Reformatsky reaction. Reactions could be carried out in diethyl ether at room temperature to generate near quantitative yields of the 3-hydroxyester. 

Allene-substituted lactams or cyclic imines are useful intermediates in the synthesis of indolizine derivatives. While the former are stable and need a Pd(0) catalyst and the presence of phenyl iodide to react < 1997TL6275>, the latter are produced in situ and react immediately (Scheme 37) <2001JA2074>. 

The lactam 145, bearing a terminal triple bond, is transformed into the corresponding allene derivative 146 through a Crabbe reaction (Equation 7). Using Pd(PPh ()4 as the catalyst and in the presence of phenyl iodide, the corresponding indolizine is obtained. The lactam nitrogen atom is added to the central carbon atom of the allene... 

Only a few attempts have been made to use Ni(PPh3)4 and Pt(PPh3)4 as catalysts in cross-coupling reactions of zinc-substituted allene 68 with phenyl iodide (cf. Eq. 14.7). In both cases the resulting coupling product 70 was formed in <5% yield [33]. 

Grigg and co-workers described a novel three-component indium-palladium-mediated allylation reaction [67]. As exemplified by Eq. 14.16, 3,3-disubstituted oxi-ndole derivative 133 was obtained smoothly from phenyl iodide, the easily available isatin imine 132 and 1,2-propadiene (131). Excellent levels of diastereoselectivity were obtained in this cascade reaction employing imines derived from enantiopure sulfmamides. 

The resting state of this catalytic system was found to be the dimer shown. The migratory insertion is the rate-determining step and not the oxidative addition of aryl halide to a palladium zero species, see Figure 13.17. These kinetics were found for phenyl iodide phenyl bromide already showed less clear-cut kinetics indicating that the oxidative addition is somewhat slower now. The system shown in Figures 13.16-17 gives at least half a million turnovers. 

The next example deals with an effect of ferrous chloride addition (Galli and Gentili 1993). Phenyl iodide reacts with the potassium derivative of l,l-dimethyl-butan-2-one (pinacolin) in DMSO according to the following equations ... 

Without illumination, the reaction proceeds slowly, but by no means it is negligible 8% of phenylpinac-olin is formed, with no regard to the prolonged duration. The addition of ferrous chloride in amounts of 40% to molar equivalent of Phi results in incisive acceleration of this reaction. The disappearance of Phi is observed within 20 min, replaced by 74% of the substitution product, PhCH2COCMe3, and ca. 10% of the disubstitution prodnct, Ph2CHCOCMe3. The authors cite diverse data, theorizing that iron(II), associated with the enolate ion, acts as an electron-transfer relay between the enolate and phenyl iodide (Scheme 5.25). 

Unfortunately, we lack measured enthalpy of formation values for most organic iodides of interest here except for ethyl, n-propyl and phenyl iodides. From equation 14 and with phenyl iodide in its reference liquid state and with ethyl and propyl iodides in their reference gaseous states, the enthalpies of formation of ethyl lithium and of n-propyl lithium are calculated to be ca —54 and —74 klmoP, respectively. The former value is the same as those from Table 1 and the latter is compatible with one of the other values for n-propyl lithium derived in earlier sections. 

Isoquinohne, 1,2,3,4-tetrahydro-2-methyl-l-(2-phenylethyl)-, 56, 7 Isoquinohnes, alkylation of, 56, 19 Isoquinohmum, 2-ethyl-3,4-dihydro-6,7-dimethoxy-l-phenyl-, iodide, 56, 7 ISOXAZOLE, 3-(4-chlorophenyl)-5-(4-methoxyphenyl)-, 55, 39 Isoxazole, 5-(4-chlorophenyl)-3-(4-meth-oxyphenyl)-, 55, 42... 

VEEL spectra of surface phenyl groups have been obtained by ultraviolet photolysis of phenyl chloride on Ag(lll) at 300 K (211) and by thermal decomposition of phenyl iodide on Cu(lll) (212). The spectra are similar, and the strengths of the absorptions from the out-of-plane yCH modes, at 740 and 725 cm-1 respectively, show that the phenyl group is also more near to parallel than to perpendicular to the metal surfaces, again probably because of a combination of cr- and 77-bonding. 

Phenyl iodide Sodium Biphenyl Sodium bromide... 

A 1,3-substituted allene, which has axial chirality instead of carbon central chirality, has been prepared by a palladium-catalyzed cross-coupling of 4,4-dimethylpenta-l,2-dienylzinc chloride (83) with phenyl iodide (5c) or by that of l-bromo-4,4-dimethylpenta- 1,2-diene (84) with phenylzinc chloride [60] (Scheme 8F.20). The highest enantiomeric purity (25% ee) of the allene (S)-85 was obtained in the former combination with (f ,/ )-diop (1) as chiral ligand. It is interesting that the enantiomeric purity was independent of the ratio of the reagents though the reaction seems to involve a kinetic resolution of the racemic 83. 

Preparation of Boc-Dpr.30,36 A mixture of diacetoxyiodobenzene (24.16 g, 75 mmol), acetonitrile (100ml), and water (100 ml) is stirred until almost complete dissolution. Acetic acid (8.6 ml, 150 mmol) is then added and solid Boc-Asn (11.61 g, 50 mmol) is introduced into the flask with acetonitrile (25 ml) and water (25 ml). The mixture is stirred at room temperature for 24 h. The phenyl iodide by-product is removed by extraction with t-BuOMe (2 x 100 ml). The aqueous layer is concentrated under reduced pressure and the solid residue is suspended in cold EtOH (100 ml), collected by filtration, and washed with cold EtOH then with Et20, and dried under vacuum to give crude Boc-Dpr as a white crystalline sohd (7.62g, 75%). 

Heck coupling of phenyl iodide with alkenes Pd(OCOCH3)2/ P(C6H5)3 B[(CH3CH2C6F13)n (n = 1,2) Solvent replacement Carroll and Holmes (1998)... 

Stille coupling of phenyl iodide with vinyl tin reagents Pd2(dba)3/tris[3,5- bis(trifluoromethyl)phenyl]-phosphine Solvent replacement Morita et al. (1998)... 

Heck coupling of phenyl iodide with acrylates Pd(02CCF3), Pd[CF3C(0)CHC(0)CF3]2 Solvent replacement Shezad et al. (1999)... 

In their pioneering work on the catalytic carbopalladation reaction of 1,2-heptadiene with phenyl iodide in the presence of a suitable base, Shimizu and Tsuji observed the formation of the corresponding substituted 1,3-dienes 62 via a / -hydride elimination from the 7z>allyl intermediate 61 [61]. Based on these observations, a three-component Heck-Diels-Alder cascade process has been developed by Grigg and co-workers [73]. A wide variety of aryl and heteroaryl iodides were used for the intermolecular reaction with dimethylallene to afford the corresponding 1,3-dienes. These subsequently react in situ with N-methylmaleimide to give the bicyclic adducts 63 (Scheme 8.30). 

An equimolar mixture of 3,4,5-trimethoxy phenyl iodide 157, lithium propargyl alkoxide 158, and diethyl ethoxymethylene malonate 159 was stirred at room temperature in the presence of a palladium catalyst. Then, to the resulting intermediate 161 potassium t-butoxide was added, and the ensuing base-promoted decarboxylative aromatization afforded tetrahydrofuran MCR adduct 162 in good yield. The ester was first reduced and the furan ring was hydrogenated with Raney nickel to furnish a diastereomeric mixture of products 163 in high yield. Further synthetic manipulations then provided a known precursor to the natural product. 

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