Regioselective Iodination of Activated Arenes Using Phenyl Trimethylammonium Dichloroiodate in Ionic Liquid Under Microwave Irradiation

Abstract

The regioselective iodination of activated arenes has been achieved in the presence of phenyltrimethylammonium dichloroiodate and ionic liquid. The reaction has been carried out by both conventional heating as well as by microwave irradiation.     

Efficient Synthesis of Bis(4-Dimethaminophenyl)arylmethanes and Bis(4-Diamethaminophenyl)alkanes Using Iodine Reagent

A novel synthetic utility of NaICl₂ for the preparation of bis(4-dimethaminophenyl)arylmethanes and bis(4-dimethaminophenyl)alkanes is described. In the presence of an aqueous solution of NaICl₂, the reaction of arenes with aromatic aldehydes gives corresponding triarylmethane derivatives regioselectively in moderate to good yields. The method is also useful for the preparation of diarylalkane derivatives by using aliphatic aldehydes.

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Ionic Liquid Iodinating Reagent for Mild and Efficient Iodination of Aromatic and Heteroaromatic Amines and Terminal Alkynes

Hexamethylene bis(N-methylimidazolium) bis(dichloroiodate) (HMBMIBDCI), an ionic liquid iodinating reagent, have been prepared and characterized. Its ability to perform iodination reactions with a variety of substrates has been explored. In general, iodination reactions of aromatic and heteroaromatic amines proceed with good yields in the absence of solvent. Reactions of terminal alkynes in the presence of 1,8-diazabicyclo [5.4.O] undec-7-ene and tetrahydrofuran have been investigated as well.

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A novel system for the synthesis of nitriles from aldehydes using aqueous ammonia and sodium dichloroiodate

A simple and mild method for the conversion of varieties of aldehydes to the corresponding nitriles using aqueous ammonia and aqueous sodium dichloroiodate reagent at room temperature is discussed. Advantages of this system are short reaction time, easy work-up and moderate to good yields.     

Kinetics and mechanism of the oxidation of formic and oxalic acids by benzyltrimethylammonium dichloroiodate

The oxidation of formic and oxalic acids by benzyltrimethylammonium dichloroiodate (BTMACI), in the presence of zinc chloride, leads to the formation of carbon dioxide. The reaction is first order with respect to BTMACI, zinc chloride and organic acid. Oxidation of deuteriated formic acid indicates the presence of a kinetic isotope effect. Addition of benzyltrimethylammonium chloride enhances the rate. It is proposed that the reactive oxidizing species is [(PhCH₂Me₃N)⁺ (IZn₂Cl₆)^-]. Suitable mechanisms have been proposed.     

Mechanoactivation of solid-phase iodochlorination of olefins with potassium dichloroiodate(I)

Mechanoactivation of iodochlorination of olefins with a new reagent, potassium dichloroiodate(I), was studied.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2357–2358, September, 1996.     

Synthesis,Characterization, X‐Ray Structural Analysis,and Iodination Ability of Benzyl(triphenyl)phosphonium Dichloroiodate

Benzyl(triphenyl)phosphonium dichloroiodate (BTPPICl₂), BnPh₃P⁺(ICl₂)^?, is easily synthesized in a nearly quantitative yield by the addition of BnPh₃P⁺Cl^? to a CH₂Cl₂ solution of iodine monochloride (ICl). BnPh₃P⁺Cl^? can be prepared by the reaction of Ph₃P and BnCl. The compound was characterized by physicochemical and spectroscopic methods (elemental analysis, FT‐IR, and ¹H‐NMR). The use of phosphonium counterion improves the quality of the BTPPICl₂ crystals. BTPPICl₂ crystallizes in the monoclinic system, and its crystal and molecular structure has been determined at 100(1) K by X‐ray diffraction. The structure was solved by the direct method and had refined R value of 0.0637 for 699 reflections (I>2σ(I)), space group P21/n with a=12.4700(3), b=13.2196(3), c=14.4580(3) Å, β=102.6340(10)°, V=2325.67(9) ų, and Z=4. The I‐atom is coordinated by two Cl‐atoms as ligands in a linear geometry. This compound is a versatile reagent for the efficient and selective iodination of organic substrates, in particular of aromatic phenols to the corresponding iodo compounds, under mild conditions. To assess the generality of method, a wide variety of phenols with electron‐donating and electron‐withdrawing substituents were studied. BTPPICl₂ is a mild iodination reagent, which offers a new avenue for an expeditious iodination of phenols. The inexpensive, relatively non‐toxic reagent, and mild conditions are the positive features of the procedure and reagent.     

Synthesis of diiodo- and triiodoanilines by iodination of aniline with potassium dichloroiodate and preparation of 1,3,5-triiodobenzene

A new chemoselective procedure was developed for the synthesis of 2,4,6-triiodoaniline and 2,4-diiodoaniline by the reaction of aniline with potassium dichloroiodate in dilute HCl. Subsequent deamination of 2,4,6-triiodoaniline afforded 1,3,5-triiodobenzene in good yield.     

Regioselective 6-iodination of 5,7-dioxygenated flavones by benzyltrimethylammonium dichloroiodate

The iodination of 5,7-dioxygenated flavones with 1 equiv of benzyltrimethylammonium dichloroiodate (BTMA·ICl₂) in the system CH₂Cl₂-MeOH-CaCO₃ at room temperature is presented in this note. Flavones with a free phenol group at C5 and an alkoxy or a peracylglycosyloxy at C7 lead to the 6-iodoflavones with a good regioselectivity (ratio 6-iodination/8-iodination about 9).     

Electrophilic addition to norbornene derivatives containing CF<Subscript>3</Subscript> and NO<Subscript>2</Subscript> groups

Electrophilic sulfenylation, selenenation, and halogenation of bicyclo[2.2.1]heptenes containing CF₃ or NO₂ group in position endo-5 were studied. The sulfenylation and selenenation were accomplished by arylsulfene- and arylselenenamides activated by POHal₃ (Hal = Br, Cl), and iodination was performed by KICl₂. The reactions are regiospecific and involve an exo-attack of the electrophilic fragment (arylthio or arylseleno group or iodine) on the C=C bond atom located closer to the CF₃ or NO₂ group. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1445–1448, June, 2005.