- A New, Simple, and General Synthesis of N -Oxides of Iodopyridines and Iodoquinolines via the Diazotization-Iodination of Heterocyclic Amino N -Oxides in the Presence of p -Toluenesulfonic Acid in Water
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The diazotization of a series of N -oxides of aminopyridines and aminoquinolines under the action of sodium nitrite in the presence of KI and p -TsOH in water at room temperature leads to the formation of the corresponding N -oxides of iodopyridines and iodoquinolines in high yields. The method has a general character and can be used for the preparation of 3-, 2-, and 4- N -oxides of iodopyridines.
- Krasnokutskaya, Elena A.,Chudinov, Alexey A.,Filimonov, Victor D.
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- A regioselectively 1,1′,3,3′-tetrazincated ferrocene complex displaying core and peripheral reactivity
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Regioselective 1,1′,3,3′-tetrazincation [C-H to C-Zn(tBu)] of ferrocene has been achieved by reaction of a fourfold excess of di-t-butylzinc (tBu2Zn) with sodium 2,2,6,6-tetramethylpiperidide (NaTMP) in hexane solution manifested in the trimetallic iron-sodium-zinc complex [Na4(TMP)4Zn4(tBu)4{(C5H3)2Fe}], 1. X-ray crystallographic studies supported by DFT modelling reveal the structure to be an open inverse crown in which two [Na(TMP)Zn(tBu)Na(TMP)Zn(tBu)]2+ cationic units surround a {(C5H3)2Fe}4- tetraanion. Detailed C6D6 NMR studies have assigned the plethora of 1H and 13C chemical shifts of this complex. It exists in a major form in which capping and bridging TMP groups interchange, as well as a minor form that appears to be an intermediate in this complicated exchange phenomenon. Investigation of 1 has uncovered two distinct reactivities. Two of its peripheral t-butyl carbanions formally deprotonate toluene at the lateral methyl group to generate benzyl ligands that replace these carbanions in [Na4(TMP)4Zn4(tBu)2(CH2Ph)2{(C5H3)2Fe}], 2, which retains its tetrazincated ferrocenyl core. Benzyl-Na π-arene interactions are a notable feature of 2. In contrast, reaction with pyridine affords the crystalline product {[Na·4py][Zn(py?)2(tBu)·py]}∞, 3, where py is neutral pyridine (C5H5N) and py? is the anion (4-C5H4N), a rare example of pyridine deprotonated/metallated at the 4-position. This ferrocene-free complex appears to be a product of core reactivity in that the core-positioned ferrocenyl anions of 1, in company with TMP anions, have formally deprotonated the heterocycle.
- Armstrong, David R.,Clegg, William,Hevia, Eva,Honeyman, Gordon W.,Kennedy, Alan R.,McLellan, Ross,Mulvey, Robert E.,Orr, Samantha A.,Parkinson, John A.,Ramsay, Donna L.,Robertson, Stuart D.,Towie, Stephen
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- Facile Access to Diverse Libraries of Internal Alkynes via Sequential Iododediazoniation/Decarboxylative Sonogashira Reaction in Imidazolium ILs without Ligand or Additive
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Convenient access to diverse libraries of internal alkynes via decarboxylative Sonogashira reaction of alkynyl-carboxylic acids with iodoarenes, employing imidazolium-ILs as solvent, along with piperidine-appended imidazolium [PAIM][NTf2] as task-specific basic IL is demonstrated, without the need for any ligand or additive. The feasibility to perform these reactions by sequential one-pot iododediazoniation/decarboxylative Sonogashira reaction is also shown, and the scope of the methods is underscored by providing 29 examples. The potential for recycling and reuse of the IL solvent is also examined.
- Prabhala, Pavankumar,Savanur, Hemantkumar M.,Kalkhambkar, Rajesh G.,Laali, Kenneth K.
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- Cheap and easy synthesis of highly functionalized (het)aryl iodides via the aromatic finkelstein reaction
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Aryl iodides are superior coupling partners in cross-couplingA- reactions compared to the corresponding chlorides or bromides. Unfortunately, the iodides are much more expensive, if commercially available at all, than the other halides. Thus, it is often mandatory to transform the available bromides into the corresponding iodides. The copper-catalyzed aromatic Finkelstein reaction turned out to be the method of choice to prepare a number of highly functionalized iodo(het)aryls, including pyridines, 2,2′-bipyridines, and chiral compounds. Georg Thieme Verlag Stuttgart? New York.
- Meyer-Eppler, Georg,Kuechler, Lea,Tenten, Christina,Benkhaeuser, Christian,Brueck, Stefanie,Luetzen, Arne
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- Synthesis, catalytic activity and medium fluorous recycle of fluorous analogues of PEPPSI catalysts
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PEPPSI complexes are air and moisture stable Pd catalysts, which can be used conveniently in many coupling reactions. With the aim to obtain Pd catalysts recyclable by fluorous separation methods, we modified the structure of commercial PEPPSI complexes by per- or polyfluoroalkylation in various positions. The modifications included the use of a linear polyfluoroalkyl group instead of one aryl group on the NHC ligand, perfluoroalkylation of pyridine ligand, and substitution of chloride ligands on Pd for perfluoroalkanoates or perfluoropolyoxaalkanoates. Comparison of catalytic activity of commercial catalysts with the modified ones in Suzuki-Miyaura cross-coupling reactions showed that the fluorous modifications mostly resulted in the increase of catalytic activity. Moreover, polyfluoroalkylation enabled efficient medium fluorous recycle of the modified catalysts using a two phase aqueous DMF/HFE 7500 ether system.
- ?im?nek, Ond?ej,Rybá?ková, Markéta,Svoboda, Martin,Kví?ala, Jaroslav
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- Pyridylmagnesium chlorides from bromo and dibromopyridines by bromine- magnesium exchange: A convenient access to functionalized pyridines
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Various bromopyridines were converted to the corresponding pyridylmagnesium chlorides at room temperature by treatment with iPrMgCl. The resulting Grignard reagents were quenched by various electrophiles to afford functionalized pyridines. The bromine-magnesium exchange of some dibromopyridines was also studied.
- Trecourt, Francois,Breton, Gilles,Bonnet, Veronique,Mongin, Florence,Marsais, Francis,Queguiner, Guy
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- AN EFFICIENT METHOD FOR SYNTHESIS OF 5-(3-PYRIDYL)-2,2'-BITHIOPHENE(SENSITIZER)
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The present invention discloses an efficient process for synthesis of photosensitizer, 5-(3-pyridyl)-2,2'-bithiophene in high yield and purity.
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Page/Page column 7; 8-9
(2021/02/05)
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- Synthesis of Azepino[1,2-a]indole-10-amines via [6+1] Annulation of Ynenitriles with Reformatsky Reagent
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Lewis acid-catalyzed [6+1] annulation reactions of 2-cyano-1-propargyl- and 2-alkynyl-1-cyanomethyl-indoles with Reformatsky reagent are described. 8-Aryl, 8-alkyl-, 8-hetaryl-, 9-aryl, and 9-alkyl-azepino[1,2-a]indole amines were obtained through a 7-endo-mode cyclization of the β-aminoacrylate intermediates. The antiproliferative activity of the azepino[1,2-a]indoles analogs against the HCT-116 cells were also examined.
- Iioka, Ryoya,Yorozu, Kohei,Sakai, Yoko,Kawai, Rika,Hatae, Noriyuki,Takashima, Katsuki,Tanabe, Genzoh,Wasada, Hiroaki,Yoshimatsu, Mitsuhiro
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supporting information
p. 1553 - 1558
(2021/02/26)
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- Metathesis-active ligands enable a catalytic functional group metathesis between aroyl chlorides and aryl iodides
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Current methods for functional group interconversion have, for the most part, relied on relatively strong driving forces which often require highly reactive reagents to generate irreversibly a desired product in high yield and selectivity. These approaches generally prevent the use of the same catalytic strategy to perform the reverse reaction. Here we describe a catalytic functional group metathesis approach to interconvert, under CO-free conditions, two synthetically important classes of electrophiles that are often employed in the preparation of pharmaceuticals and agrochemicals—aroyl chlorides (ArCOCl) and aryl iodides (ArI). Our reaction design relies on the implementation of a key reversible ligand C–P bond cleavage event, which enables a non-innocent, metathesis-active phosphine ligand to mediate a rapid aryl group transfer between the two different electrophiles. Beyond enabling a practical and safer approach to the interconversion of ArCOCl and ArI, this type of ligand non-innocence provides a blueprint for the development of a broad range of functional group metathesis reactions employing synthetically relevant aryl electrophiles.
- Lee, Yong Ho,Morandi, Bill
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p. 1016 - 1022
(2018/09/06)
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- Visible-Light-Induced Decarboxylative Iodination of Aromatic Carboxylic Acids
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A convenient, efficient and practical visible-light-induced decarboxylative iodination of aromatic carboxylic acids has been developed, and the corresponding aryl iodides were obtained in good yields. The method shows some advantages including the use of readily available aromatic carboxylic acids as the starting materials, simple and mild conditions, high efficiency, wide substrate scope and tolerance of various functional groups.
- Jiang, Min,Yang, Haijun,Jin, Yunhe,Ou, Lunyu,Fu, Hua
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supporting information
p. 1572 - 1577
(2018/06/26)
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- Late stage iodination of biologically active agents using a one-pot process from aryl amines
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A simple and effective one-pot tandem procedure that generates aryl iodides from readily available aryl amines via stable diazonium salts has been developed. The operationally simple procedure and mild conditions allow late-stage iodination of a wide range of aryl compounds bearing various functional groups and substitution patterns. A novel synthetic strategy involving the preparation of nitroaryl compounds followed by a chemoselective tin(ii) dichloride reduction and the use of the one-pot diazotisation-iodination transformation was also developed. The general applicability of this approach was demonstrated with the preparation of a number of medicinally important compounds including CNS1261, a SPECT imaging agent of the N-methyl-d-aspartate (NMDA) receptor and IBOX, a compound used to detect amyloid plaques in the brain.
- Sloan, Nikki L.,Luthra, Sajinder K.,McRobbie, Graeme,Pimlott, Sally L.,Sutherland, Andrew
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p. 54881 - 54891
(2017/12/12)
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- Using Anilines as Masked Cross-Coupling Partners: Design of a Telescoped Three-Step Flow Diazotization, Iododediazotization, Cross-Coupling Process
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The conversion of commercially available anilines into biaryl and biarylacetylene products was realized by using a telescoped, three-reactor flow diazotization/iododediazotization/cross-coupling process. The segmented flow stream created by off-gassing during the Sandmeyer sequence was restored to a continuous column of reaction solution by using a specially designed continuous-flow unit controlled by custom software created in-house. The resultant aryl iodide was then combined with a stream of cross-coupling solution that fed into the final reactor. The system proved versatile as modifications to the diazotization/iododediazotization sequence could be made rapidly to account for any substrate specificity (e.g., solubility problems), leading to a wide substrate scope of Suzuki–Miyaura and Sonogashira cross-coupled products.
- Teci, Matthieu,Tilley, Michael,McGuire, Michael A.,Organ, Michael G.
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supporting information
p. 17407 - 17415
(2016/11/23)
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- Substituent parameters impacting isomer composition and optical properties of dihydroindolizine molecular switches
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In an attempt to understand which factors influence constitutional isomer control of 6′- and 8′-substituted dihydroindolizines (DHIs), a series of asymmetric pyridines was condensed with dimethyl spiro[cycloprop[2] ene-1,9′-fluorene]-2,3-dicarboxylate. The substituents on the pyridial derivatives ranged from donating to withdrawing and demonstrated control over the isomeric ratios for all DHIs. Substituent control proved to be selective for the highly donating amino, which exclusively formed the 8′ isomer. The same ratios were reproduced via photolytic experiments, which suggested that the condensation reaction is dominated by the products thermodynamic stability. The electronic influences of the substituents extends beyond isomer control, as it impacts the DHIs optical properties and electrocyclization (switching) rates to the spiro conformers. Our results allow us to predict the syntheses and properties of future 6′- or 8′-substituted DHIs, molecules that will be applied in understanding the role of the dipole vector orientation to work function switching.
- Bartucci, Matthew A.,Ciszek, Jacob W.
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supporting information
p. 5586 - 5594
(2014/07/08)
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- Preparation and reaction of quinolinyl (or pyridinyl)phosphonium salts with base and pivalaldehyde
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α- and γ-Heteroaryltriphenylphosphonium iodides were prepared by reaction of the corresponding heteroaryl iodides with triphenylphosphine. Reaction of β-heteroaryl iodides with triphenylphosphine in the presence of a palladium catalyst gave β-heteroaryltriphenylphosphonium iodides. Elimination of the heteroaryl group was achieved by treating the heteroaryltriphenylphosphonium iodides with a base. Further, the heteroaryl group was trapped with pivalaldehyde to introduce a pivaloyl substituent onto the heteroaromatic ring.
- Shimada, Minami,Sugimoto, Osamu,Sato, Akihiro,Tanji, Ken-Ichi
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experimental part
p. 837 - 847
(2011/05/14)
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- Copper-catalyzed halogenation of arylboronic acids
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In this Letter, a copper-catalyzed halogenation of arylboronic acids was described. This reaction tolerates a variety of functional groups, providing aromatic halides with good yields. It represents a facile and mild procedure to aryl halides.
- Zhang, Guangyou,Lv, Guanglei,Li, Liping,Chen, Fan,Cheng, Jiang
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experimental part
p. 1993 - 1995
(2011/04/25)
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- Homoleptic zincate-promoted room-temperature halogen-metal exchange of bromopyridines
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Homoleptic lithium tri- and tetraalkyl zincates were reacted with a set of bromopyridines. Efficient and chemoselective bromine-metal exchanges were realized at room temperature with a substoichiometric amount of nBu 4ZnLi2·TMEDA reagent (1/3 equiv; TMEDA=N,N,N′,N′-tetramethylethylenediamine). This reactivity contrasted with that of tBu4ZnLi2·TMEDA, which was inefficient below one equivalent. DFT calculations allowed us to rationalize the formation of N...Li stabilized polypyridyl zincates in the reaction. The one-pot difunctionalization of dibromopyridines was also realized using the reagent stoichiometrically. The direct creation of C-Zn bonds in bromopyridines enabled us to perform efficient Negishi-type cross-couplings. Mild zincation! nBu4ZnLi2·TMEDA (in substoichiometric amounts) promoted efficient and chemoselective room-temperature bromine-metal exchange of a range of bromopyridines (see scheme). DFT calculations strongly supported the formation of a stabilized tripyridylzincate, which could be reacted with electrophiles or be directly involved in palladium-catalyzed cross-coupling reactions.
- Chau, Nguyet Trang Thanh,Meyer, Maxime,Komagawa, Shinsuke,Chevallier, Floris,Fort, Yves,Uchiyama, Masanobu,Mongin, Florence,Gros, Philippe C.
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experimental part
p. 12425 - 12433
(2011/01/05)
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- Chemistry of heteroaryltriphenylphosphonium iodides: Preparation from iodoheteroaromatics and elimination of the phosphonium iodide group using basic solvents
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α- and γ-Iodoheteroaromatics were found to react with triphenylphosphine to give heteroaromatictriphenylphosphonium iodides in excellent yields, β-lodoheteroaromatics, which are less reactive with triphenylphosphine compared to α- or γ-compounds, were con
- Sato, Akihiro,Sugimoto, Osamu,Tanji, Ken-ichi
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experimental part
p. 2735 - 2739
(2010/04/25)
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- A facile synthetic approach to the preparation of 3-pyridyl derivatives: Preparations and coupling reactions of 3-pyridylzinc and its analogues
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A facile synthetic approach to the direct preparation of 3pyridylzinc bromide has been demonstrated using Rieke zinc with 3-bromopyridine in the presence of a catalytic amount of lithium chloride. A variety of different electrophiles have been coupled to give the corresponding cross-coupling products in moderate to good yields. Also, this methodology has been expanded to the preparation of the corresponding organozinc reagents of 3-bromopyridine analogues. Georg Thieme Verlag Stuttgart.
- Kim, Seung-Hoi,Slocum, Tim B.,Rieke, Reuben D.
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scheme or table
p. 3823 - 3827
(2010/03/04)
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- A one-pot method for the iodination of aryl amines via stable aryl diazonium silica sulfates under solvent-free conditions
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A convenient and rapid one-pot method for the synthesis of iodoarenes is developed which involves the sequential diazotization-iodination of aromatic amines with sodium nitrite, silica sulfuric acid and potassium iodide under solvent-free conditions at room temperature. Various aromatic amines possessing electron-withdrawing groups or electron-donating groups are converted into the corresponding aryl iodides in good yields. Georg Thieme Verlag Stuttgart.
- Zarei, Amin,Hajipour, Abdol R.,Khazdoozd, Leila
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experimental part
p. 941 - 944
(2009/12/02)
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- A new, one-step, effective protocol for the iodination of aromatic and heterocyclic compounds via aprotic diazotization of amines
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We have developed a convenient one-step preparation of aromatic and some heterocyclic iodides by the sequential diazotization-iodination of the aromatic amines with a KI/NaNO2/p-TsOH system in acetonitrile at room temperature. This method has general character and allows aryl iodides with either donor or acceptor substituents in various positions to be obtained from the corresponding amines in 50-90% yield. Georg Thieme Verlag Stuttgart.
- Krasnokutskaya, Elena A.,Semenischeva, Nadya I.,Filimonov, Victor D.,Knochel, Paul
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- New syntheses of substituted pyridines via bromine-magnesium exchange
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Bromine-magnesium exchange using iPrMgCl in THF at room temperature on 2-, 3- and 4-bromopyridines allowed the synthesis of various functionalized pyridines. The methodology was successfully used for the synthesis of 4- azaxanthone. Moreover, single exchange reactions observed on 2,6-, 3,5-, 2,3- and 2,5-dibromopyridines, with complete regioselectivity in the case of 2,3- and 2,5-dibromopyridines, afforded substituted bromopyridines, which were then involved in a second exchange step to provide difunctionalized pyridines. (C) 2000 Elsevier Science Ltd.
- Trécourt, Fran?ois,Breton, Gilles,Bonnet, Véronique,Mongin, Florence,Marsais, Francis,Quéguiner, Guy
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p. 1349 - 1360
(2007/10/03)
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- Tetrahydropyridinylmethyl derivatives of pyrrolo[2,3-B]pyridine
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Disclosed is a class of pyrrolo[2,3-b]pyridine derivatives of formula (I) wherein Q represents a moiety of formula Qa or Qb, which are ligands for dopamine receptor subtypes within the body, in particular the dopamine D4 receptor subtype and are therefore useful in the treatment and/or prevention of disorders of the dopamine system, including schizophrenia.
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- Nitrogen dioxide - Sodium iodide as an efficient reagent for the one- pot conversion of aryl amines to aryl iodides under nonaqueous conditions
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Successive treatment of aromatic amines with liquid nitrogen dioxide and powdered sodium iodide in acetonitrile at -20 °C, followed by usual work- up, gave the corresponding aryl iodides in good yield. This method worked especially well for less basic amines bearing electron-withdrawing substituents.
- Suzuki, Hitomi,Nonoyama, Nobuaki
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p. 4533 - 4536
(2007/10/03)
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- Iodine-promoted decomposition of 1-aryl-3,3-dialkyltriazenes: A mild method for the synthesis of aryl iodides
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Iodine promoted decomposition of 1-aryl-3,3-dialkyltriazenes in organic solvents is shown to give high yields of the corresponding aryl iodides under extremely mild conditions. The presence of iodine greatly accelerates the reaction in both iodoalkanes as well as in non-iodinated solvents.
- Wu,Wu, Ziyan,Moore,Moore, Jeffrey S.
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p. 5539 - 5542
(2007/10/02)
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- PREPARATION D'AMINOPHENYL-, NITROPHENYL-, PYRIDYL-, ET QUINOLYLPHOSPHONATES SOUS PHOTOSTIMULATION OU ASSISTANCE METALLIQUE; ACCES AUX ACIDES AMINOPHOSPHONIQUES CORRESPONDANTS
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Our aim was to study the aromatic nucleophilic substitution between the sodium anion of diethylphosphite and several halogenated substrates like: iodo-anilines, iodo-nitrobenzenes, bromo- and iodopyridines, bromoquinoline.Two coupling processes have been evaluted.The first one is the photostimulated nucleophilic substitution (SRN1), the second the promoted arylation by transition metals.We obtain good results with the first method which is efficient and simple; by contrast the second one has given only few positive results.We describe five aromatic aminophosphonic acids.
- Bulot, J. J.,Aboujaoude, E. Elia,Collignon, N.,Savignac, P.
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p. 197 - 204
(2007/10/02)
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- Decarboxylative Ipso Halogenation of Mercury(II) Pyridinecarboxylates. Facile Formation of 3-Iodo- and 3-Bromopyridines
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Treatment of mercury(II) nicotinate with iodine and bromine in nitrobenzene at 180-185 deg C for 2 h afforded 3-iodo- and 3-bromopyridines in 44percent and 27percent yields, respectively, without any regioisomers and dihalopyridines.From mercury(II) picolinate only 2-3percent of 2-bromopyridine was obtained under similar reaction conditions, while the reaction using mercury(II) isonicotinate did not give any products.When a mixture of nicotinic acid and HgO was used in place of mercury(II) nicotinate, the halodecarboxylation occurred with similar ease.An ionic pathway involving the initial attack of electrophilic Hg(II) species on the ring-C bearing carboxyl group to afford a 3-pyridylmercury(II) compound and the subsequent replacement of the Hg(II) moiety by electrophilic iodine and bromine was proposed for this reaction.
- Uemura, Sakae,Tanaka, Sakuya,Okano, Masaya,Hamana, Masatomo
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p. 3297 - 3301
(2007/10/02)
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- Studies on Organometallic Compounds. II. Facile and Convenient Method for the Synthesis of Idoazines through Iododestannation of Trimethylstannylazines
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Trimethylsatannyl and bis(trimethylstannyl) derivatives of pyridine, quinoline, and isoquinoline were prepared from the corresponding halo and dihalo (chloro or bromo) derivatives and trimethylstannyl sodium, which was generated in situ from chlorotrimethylsatannane and sodium.These stannyl derivatives readily underwent iododestannation on treatment with iodine to produce the corresponding iodo and diiodo derivatives of pyridine, quinoline, and isoquinoline, respectively, in good yields.Keywords -trimethylsannylazine; bis(trimethylstannyl)azine; iodoazine; diiodoazine; iododestannation; trimethylstannyl sodium; chlorotrimethylstannane
- Yamamoto, Yukata,Yanagi, Akihiko
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p. 1731 - 1737
(2007/10/02)
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- STANNYLATION-IODINATION REACTION ON PYRIDINE NUCLEI. A FACILE METHOD FOR SYNTHESIS OF IODOPYRIDINES AND IODOQUINOLINES.
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Pyridines and quinolines bearing trimethylstannyl substituent at 2-, 3-, or 4-position were synthesized by the reaction of the respective chloro or bromo derivatives with trimethylstannyl sodium, generated in situ from chlorotrimethylstannane and sodium, in the range of 61-88percent yields.Upon treatment with iodine, these trimethylstannyl derivatives smoothly underwent iododemetallation to give the corresponding iodo derivatives of pyridine and quinoline in satisfactory yields.
- Yamamoto, Yutaka,Yanagi, Akihiko
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p. 1161 - 1164
(2007/10/02)
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