Copper-catalyzed alkene arylation with diaryliodonium salts

Alkenes and arenes represent two classes of feedstock compounds whose union has fundamental importance to synthetic organic chemistry. We report a new approach to alkene arylation using diaryliodonium salts and Cu catalysis. Using a range of simple alkenes, we have shown that the product outcomes differ significantly from those commonly obtained by the Heck reaction. We have used these insights to develop a number of new tandem and cascade reactions that transform readily available alkenes into complex arylated products that may have broad applications in chemical synthesis.     

Mechanism of the thermal decomposition of carboxylic salts

Summary The mechanism of the thermal decomposition of silver trichloroacetate is discussed.     

Conversion of diaryliodonium salts to aryl fluorides

The preparation of aryl fluorides by the reaction of diaryliodonium salts with KF is discussed. Generally, best results were obtained when the salt Ar₂I⁺X^? was heated with KF in the absence of solvent. The counterion, X^?, must be non-nucleophilic.     

The thermal decomposition of salts of boronic acids

Salts with the formula M[RB(OH)₃] (where M is Li, Na or K, and R is C₆H₅ or C₆H₁₁) and M[C₆H₅B(OH)₃]₂ (where M is Ca, Sr or Ba) were prepared. The thermal decomposition in air and in nitrogen proceeded through a series of intermediate compounds to the respective anhydrous metaborate salt. The possible nature of these intermediate compounds is considered.     

Rapid thermal analysis of processes of thermal decomposition of mineral salts

Kinetic curves of thermal decomposition and synthesis of mineral salts are obtained in the conditions of rapid heating approaching the heating conditions in a low-temperature plasma flow. The kinetic characteristics are used in calculations of transformations in the path of a chemical plasma reactor.

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Zusammenfassung Für thermische Zersetzung und Synthese von Mineralsalzen wurden die kinetischen Kurven unter den Bedingungen schnellen Aufheizens in Annäherung der Aufheizbedingungen in einem Niedertemperatur-Plasmastrom ermittelt. Die kinetischen Eigenschaften wurden zur Berechnung der Umwandlungen bei einem chemischen Plasmareaktor verwendet.

     

Design and asymmetric synthesis of chiral diaryliodonium salts

The application of chiral hypervalent iodine reagents in asymmetric synthesis is highly desirable, as the reagents are metal-free, environmentally benign and employed under mild conditions. Three chiral diaryliodonium salts have been designed to provide chemoselectivity and asymmetric induction in asymmetric α-phenylation of carbonyl compounds. The synthetic routes to the selected targets are detailed herein, together with a structural investigation into the diastereoselectivity of the alkylation process.     

Palladium-catalyzed cross-coupling of diaryliodonium salts with organotin compounds

M. V. Lomonosov Moscow State University, 119899 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2683–2685, November, 1992.     

Transition-metal-free synthesis of thiocyanato- or nitro-arenes through diaryliodonium salts

A transition-metal-free approach to facile synthesis of thiocyanato- and nitro-arenes was developed from KSCN (potassiumthiocyanate) or NaNO₂ with diaryliodonium salts in good yields under mild conditions. The reaction was compatible with a variety of sensitive functional substituents such as halides and nitro and ester groups. The usefulness of arylation products has been realized.     

Approach to the synthesis of indoline derivatives from diaryliodonium salts

An effective method of constructing the indoline moiety via intramolecular nucleophilic ring closure of a diaryliodonium salt is described. Diacetoxyiodoarene compounds (1a-1e) were converted into intermediate Koser's reagent and coupled with arylstannanes (7-10) to form diaryliodonium salts (11a-14e). Indoline compounds with different N-protecting groups, 15, 16, 17, and 18, were synthesized in higher yields by treating salts (11a-14e) with Cs(2)CO(3) and TEMPO. Regardless of the electronic environment of five para-substituted iodoarenes and the natures of four N-protected arylstannane groups, the conversion proceeded well to afford corresponding indolines in yields of 72-84 and 70-84%, respectively.     

Dibenzophenazine derivatives as visible photosensitizers for diaryliodonium salts

The use of two dibenzo[a,c]phenazine derivatives, 10,13‐bis(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐5‐yl)dibenzo[a,c]phenazine and 10,13‐bis(4‐hexylthiophen‐2‐yl)dibenzo[a,c]phenazine are reported as photosensitizers for diaryliodonium salt photoinitiators. Novel dyes based on the dibenzo[a,c]phenazine skeleton are shown to be efficient in carrying out the cationic photopolymerizations. Representative examples of different types of monomers including epoxide, and vinyl monomers are polymerized in the presence of the photosensitizers and diphenyliodonium hexafluorophosphate (Ph₂I⁺PF). Polymerizations are initiated at room temperature using long wavelength UV and visible light, and monitored by optical pyrometry. The photopolymerization of an epoxide monomer via solar irradiation is also demonstrated. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Palladium-catalyzed arylation of acrylic acid by diaryliodonium salts in water

M. V. Lomonosov Moscow State University, 119899 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2685–2686, November, 1992.     

Arylation of anilines: formation of diarylamines using diaryliodonium salts

Extensive studies on the reaction of the fluoride ion with diaryliodonium salts demonstrated that this is a generic process for the formation of fluoroarenes and has particular advantages for the preparation of fluorine-18 radiopharmaceuticals. During these studies it became apparent that nucleophiles other than the fluoride ion may be employed for generating substituted aromatics. This approach can be applied, using substituted anilines as the nucleophilic reagent, to the formation of a range of diarylamines in good yield. Optimised conditions for the reaction of a diaryliodonium salt with an aniline utilise TFA as the preferred counter-ion in DMF (130 °C, 24 h).     

Palladium-catalyzed arylation of enynes and electron-deficient alkynes using diaryliodonium salts

A new single-pot procedure for the synthesis of aryl alkynes is described. Palladium catalyzes the coupling reaction of diaryliodonium compounds with enynes and electron-deficient alkynes to give aryl alkynes in good yields.     

Metal-free direct arylations of indoles and pyrroles with diaryliodonium salts

Direct arylations of indoles and pyrroles with differently substituted diaryliodonium salts were shown to efficiently proceed in the absence of metal catalysts.     

Copper-catalyzed direct oxidation and N-arylation of benzylamines with diaryliodonium salts

<正>1 The study of reaction conditions Table S1 The optimization of the rate of copper slats and ligand a) Entry Anion Cu/ligand Yield b)(%) 1 2 3 OTf OTf OTf 10%:20% 10%:10% 5%:10% 91 65 45 a) Reaction conditions: 1a(0.60 mmol), 2a(0.20 mmol), Cu(OTf)2(x mol%), K2CO3(2.5 equiv.), 1,10-phenanthroline(y mol%), DMSO(2 mL), 150 °C, 24 h; b) isolated yields. Table S2 The optimization of the substrates' rate a) Entry 1a/2a(mmol) Yield b)(%) 1 2 3 4 5 6 0.2:0.2 0.2:0.24 0.2:0.4 0.6:0.2 0.4:0.2 1.0:0.2 54 60 58 91 73 83 a) Reaction conditions: 1a(x mmol), 2a(y mmol), Cu(OTf)2(10 mol%), K2CO3(2.5 equiv.), 1,10-phenanthroline(20 mol%), DMSO(2 mL), 150 °C, 24 h; b) isolated yields.