Iodide Derivatives

Copper-mediated coupling of the aryl iodide derived from l,3-bis(2-hydroxy-hexafluoroisopropyl)benzene with perfluorooctyl iodide gives the desired compound as a dimethyl sulfoxide (DMSO) complex [166] (equation 143) Even bromoarenes can be coupled [167] (equation 144)... 

Rhodium catalyzed carbonylations of olefins and methanol can be operated in the absence of an alkyl iodide or hydrogen iodide if the carbonylation is operated in the presence of iodide-based ionic liquids. In this chapter, we will describe the historical development of these non-alkyl halide containing processes beginning with the carbonylation of ethylene to propionic acid in which the omission of alkyl hahde led to an improvement in the selectivity. We will further describe extension of the nonalkyl halide based carbonylation to the carbonylation of MeOH (producing acetic acid) in both a batch and continuous mode of operation. In the continuous mode, the best ionic liquids for carbonylation of MeOH were based on pyridinium and polyalkylated pyridinium iodide derivatives. Removing the highly toxic alkyl halide represents safer, potentially lower cost, process with less complex product purification. 

Zinc halide complexes with acetophenone have been structurally characterized and form monomeric or polymeric structural motifs.346 The bromide and iodide derivatives are monomeric and the chloride derivative is a coordination polymer with bridging chlorides. 

The selective and facile cleavage of the benzylic ether linkages of 1,2,3 or 4 is accomplished by treatment with iodotrimethylsilane to form the corresponding benzylic iodide. Further addition to these iodide derivatives of 1 affords dendrimers of generation 1 with phosphonium ion sites at the periphery. Such a strategy is conducted up to generation 3 with a phosphine or a phosphonium core (Scheme 3). 

The use of a higher CO pressure allowed the same intramolecular reaction starting with alkyl iodide derivatives 49 <2000TL3035> (Scheme 17, Equation 2). Without the presence of the CO atmosphere, the same reaction affords the expected indolizine derivatives 54 and 55 <1997TL7937> (Scheme 17, Equation 3). 

The opposite of the stabilisation of an ester is its activation. If we include in the concept ester the alkyl halides, their Friedel-Crafts reactions provide familiar examples of this phenomenon. An unusual example especially relevant to our present considerations is provided by some results made available to me in advance of publication by Giusti and Andruzzi. Their results [38] on the polymerisation of styrene by iodine and hydrogen iodide can be interpreted in terms of an organic iodide derived from styrene, probably 1-phenylethyl iodide, being activated by the co-ordination of one or two molecules of iodine. This process appears to polarise the C—I bond to such an extent that the normally stable ester becomes activated to a chain-propagating species and induces a pseudocationic polymerisation ... 

Lithium carbonate, administered for affective and bipolar disorders, may enhance the effects of antithyroid drugs. Potassium iodide, used as an expectorant, is a major ingredient in many cough medications. Iodide derived from this source may enhance the effects of antithyroid drugs and lead to iodine-induced hypothyroidism. Iodine in topical antiseptics and radiological contrast agents may act in a similar manner. 

Zirconocene diiodide can promote the addition of diallylzinc to a,/1-disubstituted unactivated alkynes. Thus, in the case of 5-decyne, a 94/6 mixture of the two isomeric alkenyl iodides (derived respectively from syn and anti additions to the triple bond) was obtained after iodinolysis (equation 74)108. However, the stereoselectivity was lower for 2-butyne (80/20) and the case of unsymmetrical alkynes was not mentioned. 

Silver iodide derivatives of trialkyl-phosphines and -arsines were prepared in 1937 for comparison with their copper(I) iodide analogues.201 The preparations involved shaking the ligands with silver iodide dissolved in concentrated aqueous KI. The products were found to be tetramers and of similar structure to the Cu1 complexes. The Pr As silver complex was isomorphous with [Cul-AsEt3]4. Molecular weight determinations in a range of organic solvents showed that partial dissociation occurred in solution. 

Figure 35 1H NMR data for anti and syn iminium iodides derived from 2H-thiopyran-2-thione 145.

Palladium/silver-catalyzed Heck reactions have usually involved vinyl or aryl halides and alkenes, but these reaction conditions were also extended to allenes. Indeed, Zenner and Larock65 showed that simple alkyl allenes readily reacted with aryl and vinyl iodide derivatives in the presence of palladium acetate or chloride and silver phosphate. Moreover, the reaction could be rendered asymmetric using chiral ligands the best one was a bisoxazolidine derivative (Scheme 10.37). 

Only recently, an aliphatic analogue of the pentacoordinate cationic tin complexes 461, the triorganotin iodide derivative 466, was obtained (equation 82)918. 

Ditellurium Tris[bis(2-hydroxyethyl) dithiocarbamate] Thiocyanate1 31 mg (0.1 mmol) of tellurium bis[bis(2-hydroxycthyl)dithiocarbamate] are dissolved in 5 ml of acetone. A solution of 0.29 g (3 mmol) of potassium thiocyanate in 10 ml of 3 M acetic acid is added. The reaction mixture is stirred and kept in a Petri dish at room temperature. Over night, deep-red, needle-shaped crystals separated. The crystals are filtered, washed with 1 M acetic acid and then with diethyl ether, and finally dried over anhydrous calcium chloride yield 80% dec. > 100° (TGA). The bromide and iodide derivatives were similarly prepared in the same yield. 

The complex (f-BuCp)Sml2 3THF is a rare example of an iodide derivative and the Sm coordination polyhedron is a distorted octahedron [25]. The Sm-I bond distances are 3.107(1) and 3.186(2) A. In the complex Cp°Sml2 2THF, where Cp° = 2-methoxyethyl cyclopentadienyl, the Cp° ligand forces the two iodine atoms into cis positions while the iodines are in the transpositions in the complex (r-BuCp)Sml2 3THF. 

The addition of diorganozinc compounds to alkynes can be promoted by different metallic species snch as Cp2Zrl2 and Ni(acac)2 to give the corresponding vinylic zinc componnds (equation 72). A snbsequent hydrolysis leads to the alkene, whereas iodinolysis provides the vinyl iodide derivative. Copper-zinc species, readily obtained by the... 

A methyl iodide derivative can be prepared by treating 1.5 g of dimethyl-(pentafluorophenyl)phosphine with 2.0 g of CH3I in 25 ml of absolute ethanol at reflux temperature for 4 hr. On cooling the mixture to room temperature, hygroscopic needles are obtained these are recrystallized from an acetone-benzene mixture to give 1.0 g of colorless needles. The H nmr spectrum of the methyl iodide derivative is a doublet of triplets that is centered at t7.16 with /pH = 14.8 Hz and /ph =1.7 Hz. 

Dimethyl(pentafluorophenyl)arsine is a colorless, malodorous liquid which has a nmr spectrum in dichloromethane consisting of a triplet centered at t8.51 with /PH = 1.1 Hz. A methyl iodide derivative of the arsine can be prepared by refluxing 1.7 g of the arsine with 15 ml of methyl iodide for 2 hr. After evaporation of the solvent and recrystallization of the product from a dichloromethane-benzene mixture, a colorless compound which melts at 167-168° is obtained. The nmr spectrum of the methyl iodide derivative is a triplet at t7.16 (Jfh = 1.4 Hz) in dichloromethane, and the infrared spectrum (Nujol mull) contains strong peaks at 1080 and 980 cm characteristic of the CeFs group. Anal, (done on the methyl iodide derivative). Calcd. for C9H9-FsAsI C, 26.09 H, 2.17 1, 30.68. Found C, 25.5 H, 2.21 I, 30.1. 

This coordinated structure, which was entirely novel in 1936, is not limited to copper(I) iodide derivatives. Silver(I) iodide forms similar tetrameric compounds with tertiary phosphines and arsines, and since tetrakis(monoiodo-tri-n-propylarsinesilver), [ (C3H 7) 3As,Agl]4, is strictly isomorphous with tetrakis (monoiodo-triethylarsinecopper), the two series have identical structures Hi). 

It should be noted that direct substitution of sulfonate or iodide derivatives at C6 is sensitive to steric hindrance. Kishi reported a failure in the substitution of a primary tosylate by vinyl cuprate in the synthesis of mycalamides where C4 had two geminal methyl substituents. An alternate five step route was developed to introduce the vinyl substituent [119]. Direct substitution of a primary triflate by an aryl Grignard reagent is a key step in the formal synthesis of (+)-apicularen A from D-glucal [194]. Displacement of a triflate with an alkynyllithium has also been used in the total synthesis of (+)-panaxacol [195]. 

Fluoride, chloride, bromide, and iodide derivatives of thallium(I) are well known. Their solubilities and photosensitivity are similar to the corresponding silver(I) systems. TIE is water-soluble, whereas the chlorides, bromides, and iodides are water-insoluble solids. This property is exploited in ligand-transfer chemistry involving thallium precursors. Some solid-state structures of thal-lium(I) salts of weakly coordinated anions show TT -halide interactions. Selective abstraction of a fluoride from a C-F bond, leading to thallium fluoride, has been described. The compound [ P(CH2CH2PPh2)3 RuH( 7 -ClTl)]PF6 represents the first metal complex containing an 77 -Cl-bonded TlCl ligand. This compound act as a thallium(I)-ion carrier. 

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