Phenyl Iodonium Triflate Research Articles

3,5-Di(trifluoromethyl)phenyl(cyano)iodonium triflate as a novel and potential activator for p-tolyl thioglycoside donors.

3,5-Di(trifluoromethyl)phenyl(cyano)iodonium triflate is described as an accessible, stable, and powerful thiophile that can activate batches of p-tolyl thioglycoside donors at room temperature. Various alcoholic acceptors were efficiently glycosylated, providing the desired glycosides. The novel activation protocol features mild conditions as well as high compatibility with some classic strategies for the stereoselective construction of some biologically relevant glycosidic linkages, as exemplified by α-idosides, α-galactoamines, β-mannosides, and β-rhamnosides.

Phenyl(trifluoroethyl)iodonium-triflate-initiated ring-opening polymerization of tetrahydrofuran

A catalyst- and additive-free ring-opening polymerization of tetrahydrofuran initiated by phenyl(trifluoroethyl)iodonium triflate ([PhICH2CF3][OTf]) without using photo-irradiation is developed. The reaction proceeded at room temperature or elevated temperature to form CF3CH2-terminated polytetrahydrofuran in good yields and with different Mn(NMR) values. Phenyl(trifluoroethyl)iodonium triflate was evidenced as a much powerful mediator for cationic ring-opening polymerization of THF in comparison with other commonly used initiators. The temperature, concentration of [PhICH2CF3][OTf], and reaction time had a significant influence on both yield and number-average molecular weight of the polymerized product. This reaction provided an interesting synthetic route to novel polytetrahydrofuran bearing a trifluoroethyl end group.

Metal- and additive-free cascade trifluoroethylation/cyclization of organic isoselenocyanates by phenyl(2,2,2-trifluoroethyl)iodonium triflate

A novel and convenient cascade trifluoroethylation/cyclization of organic isoselenocyanates by phenyl(2,2,2-trifluoroethyl)iodonium triflate is reported. A series of 2-isoselenocyanobiaryls and aryl alkyl isoselenocyanates reacted with phenyl(2,2,2-trifluoroethyl)iodonium triflate in CH2Cl2 at 40 °C under metal- and additive-free conditions for 3 h to provide the corresponding trifluoroethylselenolated phenanthridines and 3,4-dihydroisoquinoline derivatives in good to excellent yields. The reaction represents the first general approach to access trifluoroethylselenolated phenanthridines and 3,4-dihydroisoquinolines from organic isoselenocyanates.

TfOH-Promoted Transition-Metal-Free Cascade Trifluoroethylation/Cyclization of Organic Isothiocyanates by Phenyl(2,2,2-trifluoroethyl)iodonium Triflate.

An efficient and transition-metal-free method for the synthesis of the structurally diversified trifluoroethylthiol phenanthridines and 3,4-dihydroisoquinolines is described. Various 2-isothiocyanobiaryls and aryl alkyl isothiocyanates reacted with phenyl(2,2,2-trifluoroethyl)iodonium triflate in CH2Cl2 in the presence of trifluoromethanesulfonic acid at 40 °C to form the corresponding trifluoroethylation/cyclization products in good to quantitative yields. This work represents the first construction of trifluoroethylthiol phenanthridine and isoquinoline derivatives from isothiocyanates in the absence of transition-metal catalysts by a one-pot procedure.

Iodonium metathesis reactions of unreactive aryl iodides

Aryl iodides that are unreactive toward various diaryliodonium triflates undergo metathesis reaction with λ3-iodanes based on a highly nucleofugal aryl iodide such as 2-iodothiophene. Examples of such reactive iodanes include phenyl(2-thienyl)iodonium triflate and bis-(2-thienyl)iodonium triflate. This observation provides support for a mechanistic hypothesis advanced earlier.

Regio- and Stereoselective Radical Perfluoroalkyltriflation of Alkynes Using Phenyl(perfluoroalkyl)iodonium Triflates.

A method for regio- and stereoselective anti-addition of the perfluoroalkyl and the triflate group of phenyl(perfluoroalkyl)iodonium triflates to alkynes is presented. The radical reaction uses cheap CuCl as a smart initiator and can be conducted in gram scale. The perfluoroalkyltriflated products are readily further functionalized, rendering this transformation valuable.

アラインを用いた複素環化合物の合成

Synthesis of nitrogen, oxygen, sulfur, and selenium containing heterocycles from aryne intermediates was reviewed. Reaction of (2-trimethylsilylphenyl)phenyliodonium triflate with thiobenzophenones in the presence of CsF gave the corresponding [4+2] cycloadducts, whereas reaction with thiopivalophenones afforded the [2+2] cycloadducts. Reaction of selones with benzyne produced from (2-trimethylsilyl)phenyl triflate also produced benzoselenetes. In the case of selenofenchone, initial cycloadduct further reacted with another molar of benzyne to give the corresponding selenoxanthene. Benzyne also reacted with ortho-substituted hydroxybenzoyl derivatives to afford the xanthene derivatives. Three component reaction involving benzyne, THF, and chloroform afforded phenyl ω-trichloroalkyl ethers via 1,3-oxonium zwitterion intermediates. Carbon-carbon single bond insertion of benzyne into β-diketones followed by intramolecular aldol reaction gave 4-substituted 2-naphthols regioselectively, which further oxidized by vanadium oxide to afford 4,4’,2,2’-binaphthols in good yields. This methodology would be applicable for the synthesis of biologically or pharmaceutically active products such as isocoumarins and benzodiazepines in one-pot operation.

Iron(II)‐Catalyzed Direct Cyanation of Arenes with Aryl(cyano)iodonium Triflates

AbstractA direct oxidative cyanation of arenes under FeII catalysis with 3,5‐di(trifluoromethyl)phenyl(cyano)iodonium triflate (DFCT) as the cyanating agent has been developed. The reaction is applicable to wide range of aromatic substrates, including polycyclic structures and heteroaromatic compounds.

Iron(II)‐Catalyzed Direct Cyanation of Arenes with Aryl(cyano)iodonium Triflates

A direct oxidative cyanation of arenes under Fe(II) catalysis with 3,5-di(trifluoromethyl)phenyl(cyano)iodonium triflate (DFCT) as the cyanating agent has been developed. The reaction is applicable to wide range of aromatic substrates, including polycyclic structures and heteroaromatic compounds.

ChemInform Abstract: Synthetic Methods for the Generation and Preparative Application of Benzyne

AbstractReview: ca. 100 refs.

ChemInform Abstract: Synthesis of 2,2,2-Trifluoroethylated Onium Salts of Nitrogen, Sulfur, and Phosphorus with (2,2,2-Trifluoroethyl)phenyliodonium Triflate.

Various 2,2,2-trifluoroethyl onium triflates were synthesized by treating tertiary amines, pyridines, quinoline, a triazole, sulfides, and a phosphine with (2,2,2-trifluoroethyl)phenyliodonium triflate. Sulfoxides and N-oxide were converted to the corresponding trifluoroethylated salts. As an application, CsF-treatment of (2,2,2-trifluoethyl)triphenylphosphonium triflate with an aldehyde was shown to produce a trifluoromethylated olefin.

ChemInform Abstract: Alkynyliodonium Salts in Organic Synthesis. Preparation of Anellated Dihydropyrroles by Cascade Addition/Bicyclization of Dienyltosylamide Anions with Phenyl(propynyl)iodonium Triflate.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: A Potential Chemical Source of C2.

Thermolysis of ethynyl(phenyl)iodonium triflate, 1, in the presence of cyclooctatetraene generates naphthalene in a reaction involving free C2 or in which 1 acts as a C2 donor.

Synthetic Methods for the Generation and Preparative Application of Benzyne

Many methods have been developed for generating benzyne. Convenient and reliable precursors extensively studied so far involve benzenediazonium-2-carboxylate and o-dihalobenzenes such as 1,2-bromofluorobenzene and 1,2-dibromobenzene. Recently, in addition to the above precursors, o-(trimethylsilyl)phenyl triflate has been put into frequent use for benzyne reactions, in which benzyne is efficiently generated under mild conditions using fluoride ion. Furthermore, o-(trimethylsilyl)phenyliodonium triflate has been developed as a more efficient benzyne precursor. This mini-review focusses on recent progress in benzyne chemistry from the viewpoint of organic synthesis. The methods for generating benzynes are classified by the conditions into four categories: basic conditions using strong bases, mild conditions using fluoride ion, thermolysis, and oxidation.

Preparation, structure, and chemistry of phosphorane-derived phenyliodonium sulfonates

New triphenylphosphorane-derived phenyliodonium triflates and tosylates were prepared by the reaction of the appropriate iodosobenzene sulfonate with stabilized phosphonium ylides. Structure of the triflate derivative was determined by a single-crystal X-ray analysis. These compounds represent a potentially useful class of reagents that combine in one molecule synthetic advantages of a phosphonium ylide and an iodonium salt.

A New and Efficient Hypervalent Iodine−Benzyne Precursor, (Phenyl)[o-(trimethylsilyl)phenyl]iodonium Triflate: Generation, Trapping Reaction, and Nature of Benzyne

A new and efficient hypervalent iodine−benzyne precursor, (phenyl)[2-(trimethylsilyl)phenyl]iodonium triflate (10), is reported. The hypervalent iodine−benzyne precursor 10 is readily prepared by reaction of 1,2-bis(trimethylsilyl)benzene with a PhI(OAc)2/TfOH reagent system. Treatment of 10 with Bu4NF in CH2Cl2 at room temperature gives high yields of the benzyne adducts in the presence of a trapping agent such as furan, 2-methylfuran, anthracene, tetraphenylcyclopentadienone, or 1,3-diphenylisobenzofuran. Especially, the result of the reaction in the presence of furan indicates a quantitative generation of benzyne and its efficient capture by the furan. Similarly, methylbenzynes (22 and 27) are efficiently generated from the corresponding methyl-substituted (trimethylsilyl)phenyliodonium triflates (12 and 13). The preparation of the hypervalent iodine−benzyne precursors, the generation of benzynes, the trapping reactions, and the nature are described in detail together with the advantages of the present...

Alkynyliodonium Salts in Organic Synthesis. Preparation of Annelated Dihydropyrroles by Cascade Addition/Bicyclization of Dienyltosylamide Anions with Phenyl(propynyl)iodonium Triflate.

The addition of simple pentadienyltosylamide derivatives to the two-carbon electrophile phenyl(propynyl)iodonium triflate initiates a sequence of transformations that furnishes complex, highly functionalized cyclopentenannelated dihydropyrrole products in moderate yields with complete stereoselection. This sequence demonstrates that diyls resulting from homolytic scission of alkylidene carbene-alkene adducts can be readily accessed under mild experimental conditions and that, in the presence of appropriate pendant functionality, these diyls can productively cyclize. The isomeric isoprene-derived tosylamides follow an abbreviated reaction course and deliver azabicyclo[3.1.0]hexanes via an isomerization that competes with diyl formation.

ChemInform Abstract: Formation and Crystal Structure of an Exocyclic Enol δ‐Lactone Obtained from Dimedone and Trimethylsilylethynyl Phenyliodonium Triflate.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Formation and crystal structure of an exocyclic enol δ‐lactone obtained from dimedone and trimethylsilylethynyl phenyliodonium triflate

AbstractThe reaction between dimedone anion and trimethylsilylethynyl phenyliodonium triflate leads to the formation of 4,4‐dimethyl‐6‐(1,5‐bistrimethylsilylpentane‐1,4‐diyne‐3‐ylidene)‐δ‐valerolactone, whose crystal structure has been determined.

Inter- and Intramolecular Addition/Cyclizations of Sulfonamide Anions with Alkynyliodonium Triflates. Synthesis of Dihydropyrrole, Pyrrole, Indole, and Tosylenamide Heterocycles

The synthesis of dihydropyrroles, pyrroles, and indoles through [3-atom + 2-atom] combination of ethyl or aryl tosylamide anions with phenyl(propynyl)iodonium triflate, and the base-mediated intramolecular bicyclization of alkynyliodonium-bearing tosylamide or tosylimide substrates to furnish bicyclic and tricyclic tosylenamide (-enimide) products, is described. A detailed discussion of the scope, limitations, byproduct formation, and the basis for observed diastereoselectivity is presented.