Tetrakis iodide

Scheme 5-25. Fourfold Heck reaction with a diazonium salt (top) and a tetrakis iodide (bottom). ...

The activity of homogeneous catalysts also has been demonstrated Wilkin son s catalyst trisftriphenylphosphme rhodium chloride induces perfluoroalkyl iodides to add to olefins at 80 [70] (equation 10) Tetrakis(triphenylphosphine)-... 

A synthetically useful virtue of enol triflates is that they are amenable to palladium-catalyzed carbon-carbon bond-forming reactions under mild conditions. When a solution of enol triflate 21 and tetrakis(triphenylphosphine)palladium(o) in benzene is treated with a mixture of terminal alkyne 17, n-propylamine, and cuprous iodide,17 intermediate 22 is formed in 76-84% yield. Although a partial hydrogenation of the alkyne in 22 could conceivably secure the formation of the cis C1-C2 olefin, a chemoselective hydrobora-tion/protonation sequence was found to be a much more reliable and suitable alternative. Thus, sequential hydroboration of the alkyne 22 with dicyclohexylborane, protonolysis, oxidative workup, and hydrolysis of the oxabicyclo[2.2.2]octyl ester protecting group gives dienic carboxylic acid 15 in a yield of 86% from 22. 

In 1988, Linstrumelle and Huynh used an all-palladium route to construct PAM 4 [21]. Reaction of 1,2-dibromobenzene with 2-methyl-3-butyn-2-ol in triethylamine at 60 °C afforded the monosubstituted product in 63 % yield along with 3% of the disubstituted material (Scheme 6). Alcohol 15 was then treated with aqueous sodium hydroxide and tetrakis(triphenylphosphine)palladium-copper(I) iodide catalysts under phase-transfer conditions, generating the terminal phenylacetylene in situ, which cyclotrimerized in 36% yield. Although there was no mention of the formation of higher cyclooligomers, it is likely that this reaction did produce these larger species, as is typically seen in Stephens-Castro coupling reactions [22]. 

When one, or both, of the interactive modules are tetradentate, bi- or tridimensional (3D) architectures can be formed. An example of 2D architecture is the (4,4) network present in the complex diiodoacetylene/Ph4P+ Cl (and the analogous complexes formed by bromide or iodide anions) [194] as well as in the complex l,6-diiodoperfluorohexane/tetrakis(4-pyridyl)pentaerythritol [195]. In all these complexes, the XB acceptor works as the tetradentate tecton sitting at the node of the network and the XB donor works as the linear bidentate module that spaces the nodes. 

For instance, adamantanoid architectures are formed on the self-assembly of tetradentate XB donors with tetradentate XB acceptors, both the complementary tectons alternating at the nodes of the network (this is the case in the complex CBr4/Et4N+Cl and its bromide and iodide analogues [192], in the complex tetrakis(4-pyridyl)pentaerythritol/tetrakis(4-iodiotetralluorophenyl)pentaerythritol [195], and in other systems [197]). 

Bis[(tris(isopropyl)cyclopentadienyl)]zinc (Zn C5(Pr1)3H2 2, 21) and bis[(tetrakis(isopropyl)cyclopentadienyl)]zinc (Zn C5(Pr1)4H 2, 22) were synthesized from the respective potassium cyclopentadienides and zinc iodide as shown in Scheme 18.50 The same slipped sandwich compounds were also isolated from zinc-reduced VC13 solutions when they were treated with these alkali metal cyclopentadienides at room temperature.51 The outcomes of these reactions suggest that zincocenes are likely intermediates in the syntheses of transition metal metallocenes, in which the metal halides have been pre-reduced with zinc. The solid-state structure of Zn G5(Pr1)4H 2 is shown in Figure 10. The sole... 

In another reduction, the propargylic phosphate 64 is reduced with samarium(II) iodide in the presence of tetrakis(triphenylphosphine)palladium and tert-butanol as a proton source the allene 65 is produced almost exclusively, <1% of the isomeric alkyne 66 being present in the product mixture [19]. 

The ring closure to form butenolides by palladium(O) catalysis can be combined with C,C bond linking, as shown by Ma and co-workers. If using tetrakis (triphenyl -phosphane)palladium(O), the products 272 are obtained from 268 (R1 = alkyl, R2 = H) and vinyl iodides or aryl bromides and iodides R3X [304]. The authors assume that... 

With catalysis by tetrakis(triphenylphosphane)palladium(0), the reaction of allenic amides 275 and aryl or vinyl iodides afforded Z-configured iminolactones 277... 

Probably, the first series of lanthanide complexes with neutral oxygen donor ligands is that of AP with the lanthanide nitrates. In 1913, Kolb (79) reported tris-AP complexes with lighter lanthanide nitrates and tetrakis-AP complexes with heavier lanthanide nitrates. Subsequently, complexes of lanthanide nitrates with AP which have a L M of 6 1 and 3 1 have also been prepared (80-82). Bhandary et al. (83) have recently shown through an X-ray crystal and molecular structure study of Nd(AP)3(N03)3 that all the nitrates are bidentate and hence the coordination number for Nd(III) is nine in this complex. Complexes of AP with lanthanide perchlorates (81, 84), iodides (81, 85), and isothiocyanates (66, 86, 87) are known. While the perchlorates and iodides in the respective complexes remain ionic, two of the isothiocyanates are coordinated in the corresponding complexes of AP with lanthanide isothiocyanates. 

Complexes of lanthanide chlorides 156,173), bromides (256), and iodides 174) with 2,6-DMePyO have also been prepared and characterized. The presence of bridging 2,6- DMePyO molecules has been suggested in the complexes of lanthanide iodides. Vicentini and De Oliveira (2 73) have reported tetrakis-2,6-DMePyO complexes with lanthanide nitrates. However, by changing the method of synthesis, tris-2,6-DMePyO complexes with the lanthanide nitrates could be prepared in this laboratory (252). All the nitrate groups in the tris-2,6-DMePyO complexes are bidentate. In the 2,4,6-TMePyO complexes (252) also the nitrate groups are coordinated to the lanthanide ion in a bidentate fashion. 

Z)-1-Hexenyl iodide 1-Hexene, 1-iodo-, (Z)- (8,9) (16538-47-9) (E)-l-Hexenyl iodide 1-Hexene, l-1odo-, (E)- (8,9) (16644-98-7) Tetrakis(triphenylphosphine)palladium Palladium,... 

The choice of catalyst is important, for instance the use of tetrakis(triphenylphos-phane)palladium(O) complex results in the quantitative cyclotrimerization of 3,3-dimethylcy-elopropene.17 In similar fashion 3,3-dimethoxycyclopropene cyciodimerizes to 3 (R = OMe, 74%) using bis(dibenzylideneacetone)paUadium(0) [Pd(dba)2] complex.18 The trisubstituted cyclopropene 4 is transformed to the head-to-head dimer 5 in the presence of copper(I) iodide.19... 

The reaction of tetrakis( -mercaptoethylamine) trinickel (II) iodide, [Ni-jNi(NH2CH2CHoS)2 2]I2, with methyl iodide was found to result in the forma-... 

Decarboxylation of halofurancarboxylic acids is usually carried out with copper and quinoline at 150-230 °C and the product often distills from the reaction mixture (71BSF242). Heating chloromercuriofurans with iodine and potassium iodide in water yields iodofurans. Thus 3,4-bis(chloromercurio)-2,5-dimethylfuran yields the diiodo compound (41%), and tetrakis(chloromercurio)furan yields tetraiodofuran (67%). Boiling sodium furan-2,5-dicar-boxylate with potassium iodide and iodine in water yields the diiodofuran, and 2,5-dibromofuran (78%) is similarly available from sodium 5-bromofuran-2-carboxylate, potassium bromide and bromine (74ZOR1341). 

Linear single bridges have been found in the structures of -iodo-bis[tris(2-diphenylarsino-ethyl)aminenickel(I)] tetraphenylborate52 and /z-iodo-bis[tetrakis(phenyl isocyanide)iodocobalt(II)] iodide.53 In both cases the metal to bridging iodide distance is long (Ni—12.994 A, Co—I 2.891 A) and this is rationalized in terms of the steric requirements of the phenyl rings on the ligands. 

Several perfluoroalkyl iodides add to alkenes in the presence of 1 mol % of tetrakis(triphenylphos-phine)palladium(O) at room temperature in fair to good yields forming fluoroalkyl iodides.52 Palladium hydride elimination is less favorable than substitution of the palladium by iodide in these examples. This is due to the reaction proceeding by an unusual radical chain mechanism (equation 17). 

Several (A/-alkenyl)iodoacetamides undergo cyclization when they are reacted with tetrakis(triphe-nylphosphine)palladium(O). The highest yields (which are generally only moderate) are obtained in DMF solution with 1,8-dimethylaminonaphthalene (Proton Sponge) to take up the hydrogen iodide formed. This reaction has been used to prepare piperidones, oxindoles, indolizidines, quinolizidines, pyrrolidines, indoles, quinolines53 and pyrrolizidines (equation 18).54... 

When the irradiation was carried out in the presence of thiophene, the corresponding bithienylcarbaldehyde 125 was obtained. The aldehydic function can be converted into the acetylene 126 and the product was treated with vinyl bromide, copper iodide, and tetrakis(triphenylpho-sphine) palladium (0) under phase-transfer conditions to give a natural bithiophene 127 isolated from Tagetes minuta (87fCS(Pl)1777). 

Scheme 60), e.g., tetrakis-TES-uric acid 404) gives tetramethyl uric acid 405) by means of methyl iodide. 

Kuroboshi, M. Waki, Y. Tanaka, H. Palladium-catalyzed tetrakis(dimethylamino)ethy-lene-promoted reductive coupling of aryl halides./. Org. Chem. 2003, 68, 3938-3942. Luo, F.-T. Jeevanandam, A. Basu, M. K. Efficient and high-turnover homocoupling reaction of aryl iodides by the use of palladacycle catalysts. A convenient way to prepare poly-p-phenylene. Tetrahedron Lett. 1998, 39, 7939-7942. 

Other early work in this field included the use of tetrakis(p-aminophenyl)-porphyrin (Fig. 7a), which was electrodeposited onto glassy carbon and showed a near-Nernstian response to iodide [76]. Electrodeposited methylthiophene-methylpyrrole copolymer was deposited and shown to give a near-Nernstian response to bromide [77]. Pyrrole-3-boronate (Fig. 7b) could be deposited to give films with a good response and marked selectivity to fluoride [78]. A cobalt aminophthalocyanine could also be electropolymerised to give a good sensor for nitrite [79] or sulphide ion [80]. 

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