Iodination mercuration

An entirely different approach to 3-haloindoles involves a mercuration/iodination sequence, which has been adopted by Hegedus to prepare 4-bromo-3-iodo-l-(4-toluenesulfonyl)indole for use in the synthesis of ergot alkaloids [20,21], We will discuss this chemistry later. 

An entirely different approach to 3-haloindoles involves a mercuration/iodination... 

TUNGSTEN CARBIDE [12070-12-1 12718-69-3 (92%WC 8% Co) 11107-01-0 (85%WC 15% Co) 37329-49-0 (78%WC 14% Co 8% Ti)] WC Finely divided material reacts violently with powerful oxidizers, fluorine, chlorine trifluoride, iodine pentafluoride, mercuric iodine, nitric oxide, nitrogen oxide, lead dioxide. See also tungsten. TURPENTINE or TURPENTINE STEAM DISTILLED (8006-64-2 9005-90-7) C.oHi,... 

A mixture of bicyclo[2.2.1]heptadiene, glacial acetic acid, and tris(triphenyl-phosphine)platinum(O) heated 64 hrs. at 120° under Ng in an autoclave exo-5-acetoxybicyclo[2.2.1]hept-2-ene. Y 95%. E. F. Magoon and L. H. Slaugh, J. Organometal. Chem. 55, 409 (1973) n//-Markownikoff addition to prim, acoxy compds. by hydroboration-mercuration-iodination cf. R. C. Larock, J. Org. Chem. 39, 834 (1974). 

The Mercurex process employs mercuric nitrate-nitric acid in a packed column (Holladay, 1979). While dilute nitric acid has been investigated, improved organic iodine remove is obtained with concentrated acid (> 10 M). Mercuric iodine complexes are formed. One treatment method involves oxidation to the iodate, followed by filtration of the iodate. The mercuric iodate can be filtered off. DF s for the mercurex process are affected by aromatic vapors and may be 100 or less. The toxicity and cost of mercury are disadvantages as well as the lack of demonstrated conversion technology for the mercurex solution. 

The 4,5-dihalogenothiazoles are obtained by cyclization-halogenation reactions as show in scheme 12 (3). 2-Acetamido-4,5-diiodothiazole has been obtained by Hurd and Wehrmeister (80). The triiodothiazole can be prepared by iodination by molecular iodine of the mercuric complex of 2-iodothiazole following the Travagli method (81). 

Mercurous fluoride [13967-25 ] Hg2p2, is less effective than Hgp2. The addition of chlorine or iodine to the reagent increases its reactivity owing to the formation of a complex between Hgp2 and HgX2 (4,12). 

The iodination reaction can also be conducted with iodine monochloride in the presence of sodium acetate (240) or iodine in the presence of water or methanolic sodium acetate (241). Under these mild conditions functionalized alkenes can be transformed into the corresponding iodides. AppHcation of B-alkyl-9-BBN derivatives in the chlorination and dark bromination reactions allows better utilization of alkyl groups (235,242). An indirect stereoselective procedure for the conversion of alkynes into (H)-1-ha1o-1-alkenes is based on the mercuration reaction of boronic acids followed by in situ bromination or iodination of the intermediate mercuric salts (243). 

Complete iodination of organic compounds can be achieved by preventing the formation of free hydrogen iodide through the addition of an oxidizing agent, neutralization of the HI with a base, or combination using mercuric salts. 

Iodides. Iodides range from the completely ionic such as potassium iodide [7681-11-0] KI, to the covalent such as titanium tetraiodide [7720-83-4J, Til. Commercially, iodides are the most important class of iodine compounds. In general, these are very soluble in water and some are hygroscopic. However, some iodides such as the cuprous, lead, silver and mercurous, are insoluble. 

The aHphatic iodine derivatives are usually prepared by reaction of an alcohol with hydroiodic acid or phosphoms trHodide by reaction of iodine, an alcohol, and red phosphoms addition of iodine monochloride, monobromide, or iodine to an olefin replacement reaction by heating the chlorine or bromine compound with an alkaH iodide ia a suitable solvent and the reaction of triphenyl phosphite with methyl iodide and an alcohol. The aromatic iodine derivatives are prepared by reacting iodine and the aromatic system with oxidising agents such as nitric acid, filming sulfuric acid, or mercuric oxide. 

Mercuric iodide (red) [7774-29-0] M 454.4, m 259 (yellow >130°), b 350°(subl), d 6.3. Crystd from MeOH or EtOH, and washed repeatedly with distilled water. Has also been mixed thoroughly with excess 0.00IM iodine solution, filtered, washed with cold distilled water, rinsed with EtOH and Et20, and dried in air. POISONOUS. 

Iodoveratrole has been prepared by iodination of veratrole in the presence of mercuric oxide and by methylation of 4-iodoguaiacol with methyl iodide in alcoholic sodium ethoxide solution. ... 

Nicotine may be detected by the colourless, crystalline mercurichloride obtained when an aqueous solution is added to a solution of mercuric chloride, by the black precipitate formed under similar conditions with potassium platinic iodide and the characteristic crystalline periodide, BI2. HI, m.p. 123°, produced on admixture, under specified conditions, 2 of ethereal solutions of nicotine and iodine (cf Anabasine, p. 43). A polarographic study of nicotine has been made by Kirkpatrick. ... 

By Iodine Mercuric Oxide Photolysis of 5a.-Hydroxy Steroids... 

A-Nor-B-homo steroids with different substitution patterns than those described above may be prepared by acid catalyzed cyclization of 3)3-hydroxy-5(10)-seco-cholest-tra/w-l(l0)-en-5-one acetate (134a) formed in 30-40% yield by mercuric oxide-iodine sensitized irradiation of cholestane-3j3,5a-diol... 

Iodine trichloride Mercuric chloride Mercurous chloride Molybdenum pentachloride... 

Styrene oxide has previously been prepared by the action of iodine, water and mercuric oxide on styrene.1 A description of Hibbert s method 2 using benzoylhydroperoxide has appeared... 

Iodination of 4 with molecular iodine in the presence of mercuric oxide formed the 3-iodo derivative (52JA4951 66CJC2283). Iodine in tetrahydro-furan oxidatively cyclized /3-(3-benzo[b]thienyl)-a-mercaptoacrylic acids rather than iodinating the thiophene ring [70JCS(C)2431]. 

Iodine acetate would seem to be unambiguously present in the iodination of pentamethylbenzene in acetic acid by iodine and mercuric acetate, since the latter components form an equilibrium mixture of iodine acetate and acetoxy-mercuric iodide and mercuric acetate speeds up the iodination332. Second-order rate coefficients of 0.078 (25 °C) and 0.299 (45 °C) were obtained, and these values are intermediate between those obtained for the reaction of bromine acetate with benzene (2.5 xlO-3) and toluene (1.2) at 25 °C, indicating that bromine acetate is the stronger electrophile. 

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