- Lithium cadmate-mediated deprotonative metalation of anisole: Experimental and computational study
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Lithium cadmates bearing different ligands were compared with efficient (TMP)3CdLi (TMP = 2,2,6,6-tetramethylpiperidino) for their ability to deprotometalate anisole. The generated arylcadmates were evidenced using I 2. The results show that it is possible to replace only one of the TMP (with a piperidino, a diisopropylamino, a butyl, or a sec-butyl) without important yield drop. In the light of DFT calculations, reaction pathways were proposed for the deprotocadmations of anisole using a triamino, an alkyldiamino, and an aminodialkyl cadmate.
- Snegaroff, Katia,Komagawa, Shinsuke,Yonehara, Mitsuhiro,Chevallier, Floris,Gros, Philippe C.,Uchiyama, Masanobu,Mongin, Florence
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Read Online
- The synthesis of bromo and iodo trifunctionalised tribenzosilatranes
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A reliable synthetic route towards selective derivatisation at the 6′,6″ and 6? positions of tribenzosilatranes with bromo or iodo groups has been developed. As these groups can be reacted further, this extends the chemistry associated with tribenzosilatranes. In this report we present a direct synthesis of bromo 8 and iodo 9 trisubstituted tribenzosilatranes. Commercially available o-anisidine 1 was transformed into the triarylamine 3 in a two-step sequence, which was halogenated to furnish the tribromo 4 or the triiodo 5 substituted triamines, respectively. Subsequent deprotection of the methyl ethers furnished the novel tripod ligands 6 and 7. A transilylation reaction in the last step led to the synthesis of the desired para-halogenated tribenzosilatranes 8 and 9.
- Alvarez, Rubén,Mehl, Georg H.
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- TMP (2,2,6,6-tetramethylpiperidide)-aluminate bases: Lithium-mediated alumination or lithiation-alkylaluminium-trapping reagents?
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The lithium TMP-aluminate bases "LiTMP·Al(iBu) 3" 1 and "LiTMP·Al(TMP)(iBu) 2" 2, where TMP is 2,2,6,6-tetramethylpiperidide, have recently come under the spotlight as "aluminating" reagents in that they can perform aluminium-hydrogen exchange on a wide variety of aromatic substrates. Previous studies have intimated that 1 existed as a single species in THF solution formulated as [(THF)·Li(μ-TMP)(μ-iBu)Al( iBu)2] 1·THF, having a contacted ion pair structure as evidenced by an X-ray crystallographic study of isolated crystals. But here using anisole as a case substrate it is revealed that pre-crystallised 1·THF cannot deprotonate anisole at all whether in hexane or THF solution contradicting earlier in situ applications of 1 which revealed near quantitative metallation of anisole. NMR spectroscopic studies of 1 made in situ in THF solution ascribe this reactivity distinction from 1·THF to complex equilibria involving five major species in LiTMP·THF, Al( iBu)3·THF, [{Li(THF)4} +{Al(TMP)(iBu)3}-] 1·(THF)4, [(THF)·Li(μ-TMP)(μ-OC4H 7)Al(iBu)2], 4, and (TMP)Al( iBu)2·THF. Reagent 2 in contrast is found to exist as only two separated homometallic species in LiTMP·THF and (TMP)Al( iBu)2·THF in THF solution. The constitutions of 1 and 2 in non-polar hexane solution are also revealed. With the aid of DFT calculations, discussion focuses on the fact that none of the aluminate species present in THF solutions of 1 or 2 can deprotonate/metallate anisole, instead the metallation processes appear to be LiTMP lithiations followed immediately by trapping by an alkylaluminium complex, in a metal exchange which drives the reaction to the product (arylaluminated) side. the Partner Organisations 2014.
- Armstrong, David R.,Crosbie, Elaine,Hevia, Eva,Mulvey, Robert E.,Ramsay, Donna L.,Robertson, Stuart D.
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- A Mild Heteroatom (O -, N -, and S -) Methylation Protocol Using Trimethyl Phosphate (TMP)-Ca(OH) 2Combination
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A mild heteroatom methylation protocol using trimethyl phosphate (TMP)-Ca(OH)2combination has been developed, which proceeds in DMF, or water, or under neat conditions, at 80 °C or at room temperature. A series of O-, N-, and S-nucleophiles, including phenols, sulfonamides, N-heterocycles, such as 9H-carbazole, indole derivatives, and 1,8-naphthalimide, and aryl/alkyl thiols, are suitable substrates for this protocol. The high efficiency, operational simplicity, scalability, cost-efficiency, and environmentally friendly nature of this protocol make it an attractive alternative to the conventional base-promoted heteroatom methylation procedures.
- Tang, Yu,Yu, Biao
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- Generation of Organozinc Reagents from Arylsulfonium Salts Using a Nickel Catalyst and Zinc Dust
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Readily available aryldimethylsulfonium triflates react with zinc powder under nickel catalysis via the selective cleavage of the sp2-hybridized carbon-sulfur bond to produce salt-free arylzinc triflates under mild conditions. This zincation displays superb chemoselectivity and thus represents a protocol that is complementary or orthogonal to existing methods. The generated arylzinc reagents show both high reactivity and chemoselectivity in palladium-catalyzed and copper-mediated cross-coupling reactions.
- Yamada, Kodai,Yanagi, Tomoyuki,Yorimitsu, Hideki
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p. 9712 - 9718
(2021/01/09)
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- Orthogonal Stability and Reactivity of Aryl Germanes Enables Rapid and Selective (Multi)Halogenations
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While halogenation is of key importance in synthesis and radioimaging, the currently available repertoire is largely designed to introduce a single halogen per molecule. This report makes the selective introduction of several different halogens accessible. Showcased here is the privileged stability of nontoxic aryl germanes under harsh fluorination conditions (that allow selective fluorination in their presence), while displaying superior reactivity and functional-group tolerance in electrophilic iodinations and brominations, outcompeting silanes or boronic esters under rapid and additive-free conditions. Mechanistic experiments and computational studies suggest a concerted electrophilic aromatic substitution as the underlying mechanism.
- Deckers, Kristina,Fricke, Christoph,Schoenebeck, Franziska
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supporting information
p. 18717 - 18722
(2020/08/25)
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- Dehydroxyalkylative halogenation of C(aryl)-C bonds of aryl alcohols
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We herein report Cu mediated side-directed dehydroxyalkylative halogenation of aryl alcohols. C(aryl)-C bonds of aryl alcohols were effectively cleaved, affording the corresponding aryl chlorides, bromides and iodides in excellent yields. Aryl alcohols could serve as both aromatic electrophilic and radical synthetic equivalents during the reaction.
- Liu, Mingyang,Zhang, Zhanrong,Liu, Huizhen,Wu, Tianbin,Han, Buxing
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supporting information
p. 7120 - 7123
(2020/07/14)
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- Mechanism of Cu-catalyzed aryl boronic acid halodeboronation using electrophilic halogen: Development of a base-catalyzed iododeboronation for radiolabeling applications
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An investigation into the mechanism of Cu-catalyzed aryl boronic acid halodeboronation using electrophilic halogen reagents is reported. Evidence is provided to show that this takes place via a boronate-driven ipso-substitution pathway and that Cu is not required for these processes to operate: General Lewis base catalysis is operational. This in turn allows the rational development of a general, simple, and effective base-catalyzed halodeboronation that is amenable to the preparation of 125I-labeled products for SPECT applications.
- Molloy, John J.,O'rourke, Kerry M.,Frias, Carolina P.,Sloan, Nikki L.,West, Matthew J.,Pimlott, Sally L.,Sutherland, Andrew,Watson, Allan J. B.
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supporting information
p. 2488 - 2492
(2019/04/10)
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- Facile and practical synthesis of π-extended oxepins by benzannulation and intramolecular cyclization
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π-Extended oxepins 1 and dimer 8 were synthesized by the benzannulation of the corresponding asymmetric diarylacetylene derivatives and 2-(phenylethynyl)benzaldehyde followed by the Cu-catalyzed intramolecular cyclization. The optical properties of the π-extended oxepins 1 and 8 are also investigated.
- Umeda, Rui,Shimizu, Yuji,Ida, Yuta,Ikeshita, Masahiro,Suzuki, Shuichi,Naota, Takeshi,Nishiyama, Yutaka
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p. 183 - 186
(2018/12/11)
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- Alkali Metal Effects in Trans-Metal-Trapping (TMT): Comparing LiTMP with NaTMP in Cooperative MTMP/Ga(CH2SiMe3)3 Metalation Reactions
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Stepwise metalation and trapping, so called trans-metal-trapping (TMT), of anisole is studied using LiTMP as base and Ga(CH2 SiMe3)3 as trap. The isolated 'trapped' intermediate is also assessed in C-C bond forming reactions, highlighting the inherent advantages and remaining challenges of this system. The same base trap mixture is found to metallate N-Me bonds of the diamines TMEDA and PMDETA. Comparative studies replacing LiTMP by NaTMP have found significant alkali metal effects on the extent of both base-trap cocomplexation and onward reactivities of TMT products.
- McLellan, Ross,Uzelac, Marina,Bole, Leonie J.,Gil-Negrete, Jose María,Armstrong, David R.,Kennedy, Alan R.,Mulvey, Robert E.,Hevia, Eva
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p. 1207 - 1215
(2019/02/26)
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- One of iodinated aromatic ring by iodine chloride in hydrochloric acid (by machine translation)
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[Problem] to one iodine chloride is used, and, stably iodinated aromatic compound can be iodinated aromatic compound production. [Solution] water containing one iodine chloride hydrogen chloride, iodine chloride content of 30% by mass of the first mass % -70, 3 mass % -20 mass % aqueous solution of hydrogen chloride content in the preparing step, a process for preparing an aromatic compound as the reaction substrate, the reaction substrate as an aqueous solution of the mixture of aromatic compounds, as the reaction substrate of one iodine chloride by reacting an aromatic compound, iodinated aromatic compound obtained in the step, the iodinated aromatic compound. [Drawing] no (by machine translation)
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Paragraph 0063-0066
(2019/09/10)
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- Decarboxylative Suzuki-Miyaura coupling of (hetero)aromatic carboxylic acids using iodine as the terminal oxidant
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A novel methodology for the decarboxylative Suzuki-Miyaura-type coupling has been established. This process uses iodine or a bromine source as both the decarboxylation mediator and the terminal oxidant, thus avoiding the need for stoichiometric amounts of transition metal salts previously required. Our new protocol allows for the construction of valuable biaryl architectures through the coupling of (hetero)aromatic carboxylic acids with arylboronic acids. The scope of this decarboxylative Suzuki reaction has been greatly diversified, allowing for previously inaccessible non-ortho-substituted aromatic acids to undergo this transformation. The procedure also benefits from low catalyst loadings and the absence of stoichiometric transition metal additives.
- Quibell, Jacob M.,Duan, Guojian,Perry, Gregory J.P.,Larrosa, Igor
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supporting information
p. 6445 - 6448
(2019/06/07)
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- Deprotonative Metalation of Methoxy-Substituted Arenes Using Lithium 2,2,6,6-Tetramethylpiperidide: Experimental and Computational Study
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The reaction pathways of lithium 2,2,6,6-tetramethylpiperidide (LiTMP)-mediated deprotonative metalation of methoxy-substituted arenes were investigated. Importantly, it was experimentally observed that, whereas TMEDA has no effect on the course of the reactions, the presence of more than the stoichiometric amount of LiCl is deleterious, in particular without an in situ trap. These effects were corroborated by the DFT calculations. The reaction mechanisms, such as the structure of the active species in the deprotonation event, the reaction pathways by each postulated LiTMP complex, the stabilization effects by in situ trapping using zinc species, and some kinetic interpretation, are discussed herein.
- Akimoto, Gaku,Otsuka, Mai,Takita, Ryo,Uchiyama, Masanobu,Hedidi, Madani,Bentabed-Ababsa, Ghenia,Lassagne, Frédéric,Erb, William,Mongin, Florence
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p. 13498 - 13506
(2018/11/20)
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- Regioselective Halogenation of Arenes and Heterocycles in Hexafluoroisopropanol
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Regioselective halogenation of arenes and heterocycles with N-halosuccinimides in fluorinated alcohols is disclosed. Under mild condition reactions, a wide diversity of halogenated arenes are obtained in good yields with high regioselectivity. Additionally, the versatility of the method is demonstrated by the development of one-pot sequential halogenation and halogenation-Suzuki cross-coupling reactions.
- Tang, Ren-Jin,Milcent, Thierry,Crousse, Benoit
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p. 930 - 938
(2018/01/28)
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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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- Electrochemical Synthesis of Aryl Iodides by Anodic Iododesilylation
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An electrochemical access to iodinated aromatic compounds starting from trimethylsilyl-substituted arenes is presented. By design of experiments, highly efficient and mild conditions were identified for a wide range of substrates. A functional group stability test and the synthesis of an important 3-iodobenzylguanidine radiotracer illustrate the scope of this process.
- M?ckel, Robert,Hille, Jessica,Winterling, Erik,Weidemüller, Stephan,Faber, Tabea Melanie,Hilt, Gerhard
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supporting information
p. 442 - 445
(2018/02/21)
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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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- Copper-catalysed aromatic-Finkelstein reactions with amine-based ligand systems
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A new efficient and low-cost ligand, diethylenetriamine, has been utilised to promote the iodination of 16 different bromo-substrates via the copper catalysed Finkelstein halogen exchange reaction under mild conditions. In contrast to earlier methods, the use of inert atmosphere conditions was not required to obtain high yields and purity. Studies on the speciation of the catalyst in solution indicate rapid disproportionation of copper(i) in the presence of diethylenetriamine to give copper(0) and a bis-ligated copper(ii) complex which is characterised by X-ray diffraction. This copper(ii) complex was also shown to be catalytically active in the halogen exchange reaction. In contrast, no significant disproportionation was observed using dimethylethylenediamine as the ligand, and the solid-state structures of a copper(i) dimeric complex and a 2D polymeric network of copper(i) iodide tetramers are reported. The catalytic activity of diethylenetriamine and dimethylethylenediamine with both copper(i) and copper(ii) salts are compared, and possible mechanistic implications discussed.
- Jin, Xiaodong,Davies, Robert P.
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p. 2110 - 2117
(2017/07/22)
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- Transition-Metal-Free Decarboxylative Iodination: New Routes for Decarboxylative Oxidative Cross-Couplings
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Constructing products of high synthetic value from inexpensive and abundant starting materials is of great importance. Aryl iodides are essential building blocks for the synthesis of functional molecules, and efficient methods for their synthesis from chemical feedstocks are highly sought after. Here we report a low-cost decarboxylative iodination that occurs simply from readily available benzoic acids and I2. The reaction is scalable and the scope and robustness of the reaction is thoroughly examined. Mechanistic studies suggest that this reaction does not proceed via a radical mechanism, which is in contrast to classical Hunsdiecker-type decarboxylative halogenations. In addition, DFT studies allow comparisons to be made between our procedure and current transition-metal-catalyzed decarboxylations. The utility of this procedure is demonstrated in its application to oxidative cross-couplings of aromatics via decarboxylative/C-H or double decarboxylative activations that use I2 as the terminal oxidant. This strategy allows the preparation of biaryls previously inaccessible via decarboxylative methods and holds other advantages over existing decarboxylative oxidative couplings, as stoichiometric transition metals are avoided.
- Perry, Gregory J. P.,Quibell, Jacob M.,Panigrahi, Adyasha,Larrosa, Igor
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supporting information
p. 11527 - 11536
(2017/08/30)
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- Palladium-Catalyzed Norbornene-Mediated Tandem Amination/Cyanation Reaction: A Method for the Synthesis of ortho-Aminated Benzonitriles
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A palladium-catalyzed, norbornene-mediated tandem amination/cyanation reaction via Catellani-type C-H functionalization was developed using N-benzoyloxyamines as the amination reagent and Zn(CN)2 as the terminating agent. This transformation, in which one C-N bond and one C-C bond are formed, provides an efficient approach for the synthesis of ortho-aminated benzonitriles in one pot from easily accessible starting materials.
- Luo, Bo,Gao, Jin-Ming,Lautens, Mark
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supporting information
p. 4166 - 4169
(2016/10/12)
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- Copper-mediated aerobic iodination and perfluoroalkylation of boronic acids with (CF3)2CFI at room temperature
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The copper-mediated aerobic reactions between the branched (CF3)2CFI and boronic acids (R-B(OH)2) are described. Different from the linear perfluoroalkyl analogs CF3(CF2)nI (n?=?2, 3, 5, 7), (CF3)2CFI reacting with R-B(OH)2at room temperature under air in the presence of catalytic Cu powder provided exclusively the corresponding iodides (R-I), while the aerobic reactions of arylboronic acids with (CF3)2CFI at room temperature in the presence of Cu(OAc)2gave the perfluoroalkylation products (R-CF(CF3)2) in acceptable to moderate yields. The iodination reaction could be further promoted by hydroquinone, the addition of which improved the oxidation ability of (CF3)2CFI and provided the ipso-iodination products in high yields. The perfluoroalkylation was facilitated by the copper carboxylates since the addition of these salts into the reaction mixtures could successfully give rise to Ar-CF(CF3)2.
- Liu, Xi-Hai,Leng, Jing,Jia, Su-Jiao,Hao, Jian-Hong,Zhang, Fanglin,Qin, Hua-Li,Zhang, Cheng-Pan
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- Silver(I)-catalyzed iodination of arenes: Tuning the lewis acidity of N-iodosuccinimide activation
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A mild and rapid method for the iodination of arenes that utilizes silver(I) triflimide as a catalyst for activation of N-iodosuccinimide has been developed. The transformation was found to be general for a wide range of anisole, aniline, acetanilide, and phenol derivatives and allowed the late-stage iodination of biologically active compounds such as PIMBA, a SPECT imaging agent of breast cancer, and (a?)-IBZM, a dopamine D2 receptor antagonist. The method was also modified for the radioiodination of arenes using a one-pot procedure involving the in situ generation of [125I]-N-iodosuccinimide followed by the silver(I)-catalyzed iodination.
- Racys, Daugirdas T.,Sharif, Salaheddin A. I.,Pimlott, Sally L.,Sutherland, Andrew
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p. 772 - 780
(2016/02/18)
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- Zinc(II)-Assisted Aryl Finkelstein Reaction for the Synthesis of Aryl Iodides
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Aryl iodides play an important role in synthetic organic chemistry as they are frequently utilized in cross-coupling reactions and in oxidation processes using hypervalent iodine compounds. Their synthesis is, however, often cumbersome and may lead to unwanted side products. Here, we report on an improved protocol for the aryl Finkelstein reaction in which dehalogenation is prevented by addition of zinc iodide in lieu of copper(I). Generally, electron-poor ortho-bromo methyl benzoates, amides, and even unprotected phenols are well-suited for this method.
- Ueberschaar, Nico,Heine, Daniel,Hertweck, Christan
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p. 1794 - 1797
(2016/07/16)
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- Easy Access to Difluoromethylene-Containing Arene Analogues through Palladium-Catalysed C–H Olefination
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An efficient palladium-catalysed ortho-C–H olefination of α,α-difluorophenylacetic acid derivatives using 8-aminoquinoline as a bidentate directing group has been developed. A range of olefinated arenes can thus be synthesized in a concise way. This reaction provides an easy and straightforward route to a panel of difluoromethylated arene analogues in moderate to good yields, with a satisfactory tolerance of common functional groups. Transformation of the products into a variety of other difluoromethylene-containing compounds demonstrates the utility of this method.
- Shao, Changdong,Shi, Guangfa,Zhang, Yanghui
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supporting information
p. 5529 - 5538
(2016/11/25)
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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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- Sono-bromination of aromatic compounds based on the ultrasonic advanced oxidation processes
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A novel, mild "sono-halogenation" of various aromatic compounds with potassium halide was investigated under ultrasound in a biphasic carbon tetrachloride/water medium. The feasibility study was first undertaken with the potassium bromide and then extended to chloride and iodide analogues. This methodology could be considered as a new expansion of the ultrasonic advanced oxidation processes (UAOPs) into a synthetic aspect as the developed methodology is linked to the sonolytic disappearance of carbon tetrachloride. Advantages of the present method are not only that the manipulation of the bromination is simple and green, but also that the halogenating agents used are readily available, inexpensive, and easy-handling.
- Fujita, Mitsue,Lévêque, Jean-Marc,Komatsu, Naoki,Kimura, Takahide
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p. 247 - 251
(2015/06/08)
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- Highly Regioselective Iodination of Arenes via Iron(III)-Catalyzed Activation of N-Iodosuccinimide
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An iron(III)-catalyzed method for the rapid and highly regioselective iodination of arenes has been developed. Use of the powerful Lewis acid, iron(III) triflimide, generated in situ from iron(III) chloride and a readily available triflimide-based ionic liquid allowed activation of N-iodosuccinimide (NIS) and efficient iodination under mild conditions of a wide range of substrates including biologically active compounds and molecular imaging agents.
- Racys, Daugirdas T.,Warrilow, Catherine E.,Pimlott, Sally L.,Sutherland, Andrew
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supporting information
p. 4782 - 4785
(2015/10/12)
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- Metal-free iodination of arylboronic acids and the synthesis of biaryl derivatives
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A simple, general and efficient method is developed for the metal-free iodination of arylboronic acids. The protocol uses very cheap molecular iodine as the halide source and potassium carbonate as the base. The method is highly tolerant of various functional groups present in the substrates. Importantly, the iodination strategy can also be applied very effectively in the one-pot, two-step synthesis of biaryl derivatives. Georg Thieme Verlag Stuttgart New York.
- Niu, Liting,Zhang, Hao,Yang, Haijun,Fu, Hua
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supporting information
p. 995 - 1000
(2014/05/06)
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- Potassium-alkyl magnesiates: Synthesis, structures and Mg-H exchange applications of aromatic and heterocyclic substrates
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Using structurally well-defined dipotassium-tetra(alkyl)magnesiates, a new straightforward methodology to promote regioselective Mg-H exchange reactions of a wide range of aromatic and heteroaromatic substrates is disclosed. Contacted ion pair intermediates are likely to be involved, with K being the key to facilitate the magnesiation processes. This journal is
- Baillie, Sharon E.,Bluemke, Tobias D.,Clegg, William,Kennedy, Alan R.,Klett, Jan,Russo, Luca,De Tullio, Marco,Hevia, Eva
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supporting information
p. 12859 - 12862
(2014/12/11)
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- An in situ acidic carbon dioxide/glycol system for aerobic oxidative iodination of electron-rich aromatics catalyzed by Fe(NO3)3·9H2O
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An environmentally benign CO2/glycol reversible acidic system was developed for the iron(iii)-catalyzed aerobic oxidative iodination of electron-rich aromatics without the need for any conventional acid additive or organic solvent. Notably, moderate to high isolated yields (up to 97%) of the aryl iodides were attained with comparable regioselectivity when ferric nitrate nonahydrate was used as the catalyst with molecular iodine under 1 MPa of CO2.
- Ma, Ran,Huang, Cheng-Bin,Liu, An-Hua,Li, Xue-Dong,He, Liang-Nian
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p. 4308 - 4312
(2015/01/08)
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- Identification of malate dehydrogenase 2 as a target protein of the HIF-1 inhibitor LW6 using chemical probes
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Tracking the target: To identify a protein that binds directly to the HIF-1α inhibitor LW6, a series of new chemical probes were synthesized with a clickable tag and/or a photoactivatable moiety. LW6 was found to be localized to the mitochondria (see picture) and MDH2 was identified as a target protein of LW6. These results indicate that the HIF-1α inhibitory activity of LW6 is a consequence of MDH2 suppression. Copyright
- Lee, Kyeong,Ban, Hyun Seung,Naik, Ravi,Hong, Ye Seul,Son, Seohyun,Kim, Bo-Kyung,Xia, Yan,Song, Kyung Bin,Lee, Hong-Sub,Won, Misun
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supporting information
p. 10286 - 10289
(2013/10/21)
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- Computed CH acidity of biaryl compounds and their deprotonative metalation by using a mixed lithium/Zinc-TMP base
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With the aim of synthesizing biaryl compounds, several aromatic iodides were prepared by the deprotonative metalation of methoxybenzenes, 3-substituted naphthalenes, isoquinoline, and methoxypyridines by using a mixed lithium/zinc-TMP (TMP=2,2,6,6-tetramethylpiperidino) base and subsequent iodolysis. The halides thus obtained, as well as commercial compounds, were cross-coupled under palladium catalysis (e.g., Suzuki coupling with 2,4-dimethoxy-5-pyrimidylboronic acid) to afford various representative biaryl compounds. Deprotometalation of the latter compounds was performed by using the lithium/zinc-TMP base and evaluated by subsequent iodolysis. The outcome of these reactions has been discussed in light of the CH acidities of these substrates, as determined in THF solution by using the DFT B3LYP method. Except for in the presence of decidedly lower pKa values, the regioselectivities of the deprotometalation reactions tend to be governed by nearby coordinating atoms rather than by site acidities. In particular, azine and diazine nitrogen atoms have been shown to be efficient in inducing the reactions with the lithium/zinc-TMP base at adjacent sites (e.g., by using 1-(2-methoxyphenyl)isoquinoline, 4-(2,5-dimethoxyphenyl)-3-methoxypyridine, or 5-(2,5-dimethoxyphenyl)-2,4-dimethoxypyrimidine as the substrate), a behavior that has already been observed upon treatment with lithium amides under kinetic conditions. Finally, the iodinated biaryl derivatives were involved in palladium-catalyzed reactions. Copyright
- Kadiyala, Raghu Ram,Tilly, David,Nagaradja, Elisabeth,Roisnel, Thierry,Matulis, Vadim E.,Ivashkevich, Oleg A.,Halauko, Yury S.,Chevallier, Floris,Gros, Philippe C.,Mongin, Florence
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p. 7944 - 7960
(2013/07/05)
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- Halogenation and DNA cleavage via thermally stable arenediazonium camphorsulfonate salts
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A series of stable arenediazonium camphorsulfonate salts (2a-2j) were synthesized by simple diazotization of several aromatic amines in the presence of sodium nitrite and camphorsulfonic acid. All the new arenediazonium camphorsulfonates, which were characterized by multinuclear (1H and 13C) NMR, IR, DSC, and X-ray diffraction analysis (2e and 2f) provide unambiguous proof for the molecular structures of 2e and 2f. The efficient application of these salts in halogenation reactions was studied in solvent and solvent-free conditions and the DNA cleavage activity was also assessed. These arenediazonium camphorsulfonate salts are noticed as efficient DNA cleaving agents.
- Vajpayee, Vaishali,Moon, Mi Eun,Lee, Sunmi,Ravikumar, Sambandam,Kim, Hyunuk,Ahn, Byungchan,Choi, Seoyoon,Hong, Soon Ho,Chi, Ki-Whan
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p. 3511 - 3517
(2013/04/23)
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- New highly soluble dimedone-derived iodonium ylides: Preparation, X-ray structure, and reaction with carbodiimide leading to oxazole derivatives
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Highly soluble dimedone-derived o-alkoxyphenyliodonium ylides have been prepared and characterized by single crystal X-ray diffraction. These new iodonium ylides are useful reagents for the preparation of oxazole derivatives by reaction with carbodiimides. The Royal Society of Chemistry 2012.
- Zhu, Chenjie,Yoshimura, Akira,Solntsev, Pavlo,Ji, Lei,Wei, Yunyang,Nemykin, Victor N.,Zhdankin, Viktor V.
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supporting information
p. 10108 - 10110
(2012/11/13)
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- (Chiral) lithium-(magnesium-)zinc and lithium-cobalt combinations as dual reagents for aromatic deproto-metalation and aryl transfer to aldehydes
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The deprotonating ability of mixed lithium-zinc or lithium-magnesium-zinc combinations containing amido and alkyl ligands in tetrahydrofuran were compared using anisole as substrate and iodine to quantitatively trap the formed arylmetal species. The results showed that the deprotonating ability is hampered if a Grignard reagent is employed to introduce the alkyl ligand, and is reduced when 2,2,6,6-tetramethylpiperidino ligands are replaced by less hindered/basic chiral amido or alkyls. Concerning the interception of the generated lithium-zinc aryl species by aldehydes, the presence of amido ligands leads to side reactions/lower yields, and no clear improvement was observed if lithium-magnesium-zinc aryl species are used. Racemic mixtures to very low enantioselectivities were noted when chiral amido ligands were incorporated in the composition of the bases. Still with enantioselective aryl transfer to aldehyde as purpose, the deprotonating ability of mixed lithium-cobalt combinations containing amido and alkyl ligands were compared using anisole as substrate and anisaldehyde to trap the formed arylmetal species. As before, the deprotonating ability is reduced when 2,2,6,6-tetramethylpiperidino ligands are replaced by less hindered/basic alkyls or chiral amido. The trapping step using aldehydes being in this case more efficient, even in the presence of amido ligands, the alcohols were obtained in higher yields. With recourse to a lower interception temperature, and using only bis[(R)-1-phenylethyl]amino as ligands, 32 and 22% yield, and 69 and 65% ee were obtained using, respectively, anisaldehyde and 3,4,5-trimethoxybenzaldehyde to intercept the metalated anisole.
- Tilly, David,Snégaroff, Katia,Dayaker, Gandrath,Chevallier, Floris,Gros, Philippe C.,Mongin, Florence
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supporting information
p. 8761 - 8766
(2012/11/07)
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- Deprotonative metalation of aromatic compounds using mixed lithium-iron combinations
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The deprotonation of 2-methoxypyridine was attempted using putative (TMP)3FeLi prepared from different iron sources. Using iodine to intercept the metalated 2-methoxypyridine, the best result was obtained from FeBr2 (1 equiv) using THF at room temperature; nevertheless, in addition to the expected iodide, the corresponding 2,2′-dimer was obtained (86% total yield). The origin of the competitive formation of the 2,2′-dimer was not identified but mechanisms were suggested to explain its formation. It was observed that the nature of the electrophile employed to trap the 3-metalated 2-methoxypyridine has a strong impact on this dimer formation, the latter being favored using iodine (35% yield), but also benzophenone (28%), benzoyl chloride (22%), methyl iodide (27%), allyl bromide (15%), benzyl bromide (41%), and tetramethylthiuram disulphide (36%); for this reason, the yields of the expected derivatives were only 51, 15, 62, 0, 5, 18, and 0%, respectively. In contrast, using aldehydes readily led to the expected pyridine alcohols without dimerization (59% yield using 3,4,5-trimethoxybenzaldehyde and 66% yield using pivalaldehyde). 2,6-Dimethoxypyridine (in 68% yield), anisole (47%), 2,4-dimethoxypyrimidine (50% at C5 and 3% at C6), 2-fluoropyridine (64%), and thiophene (49%) were similarly converted into the corresponding alcohols after subsequent trapping with pivalaldehyde. Using iodine to trap the 2-metalated anisole did not lead to dimer formation, and 2-iodoanisole was isolated in 71% yield.
- Nagaradja, Elisabeth,Chevallier, Floris,Roisnel, Thierry,Jouikov, Viatcheslav,Mongin, Florence
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experimental part
p. 3063 - 3073
(2012/06/01)
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- Design, preparation, X-ray crystal structure, and reactivity of o-alkoxyphenyliodonium bis(methoxycarbonyl)methanide, a highly soluble carbene precursor
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The preparation, X-ray structure, and reactivity of new, highly soluble, and reactive iodonium ylides derived from malonate methyl ester and bearing an ortho substituent on the phenyl ring are reported. These new reagents show higher reactivity than common phenyliodonium ylides in the Rh-catalyzed cyclopropanation, C-H insertion, and transylidation reactions under homogeneous conditions.
- Zhu, Chenjie,Yoshimura, Akira,Ji, Lei,Wei, Yunyang,Nemykin, Victor N.,Zhdankin, Viktor V.
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supporting information; experimental part
p. 3170 - 3173
(2012/08/07)
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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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- Cobalt-catalyzed preparation of arylindium reagents from aryl and heteroaryl bromides
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A cobalt-bathophenanthroline catalyst has been developed for the direct preparation of a variety of arylindium reagents from the corresponding aryl and heteroaryl bromides in the presence of indium metal and lithium chloride. The thus-formed arylindium reagents undergo efficient palladium-catalyzed cross-coupling reactions with aryl iodides, tolerating various functional groups including hydroxy and free amino groups.
- Adak, Laksmikanta,Yoshikai, Naohiko
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experimental part
p. 7563 - 7568
(2011/11/12)
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- A green procedure for the diazotization-iodination of aromatic amines under aqueous, strong-acid-free conditions
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A convenient and mild one-pot method for the synthesis of iodoarenes in high yields by the sequential diazotization-iodination of aromatic amines with a reusable polymeric diazotization agent in the presence of p-toluenesulfonic acid at room temperature in water was developed. The method is general and is the greenest alternative of the known diazotization-iodination methods. The method is also effective for the preparation of 1H-benzo[d][1,2,3]triazole and benzo[d][1,2,3]thiadiazole. Georg Thieme Verlag Stuttgart ? New York.
- Trusova, Marina E.,Krasnokutskaya, Elena A.,Postnikov, Pavel S.,Choi, Younghwa,Chi, Ki-Whan,Filimonov, Victor D.
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experimental part
p. 2154 - 2158
(2011/08/05)
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- PROCESS FOR THE PREPARATION OF IODIDES
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This invention is directed to a process for the preparation of high yield alkyl or aryl iodide from its corresponding carboxylic acid using N-iodo amides.
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Page/Page column 35
(2012/01/05)
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- Deprotonative metalation of aromatic compounds by using an amino-based lithium cuprate
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Deprotonative cupration of aromatic compounds by using amino-based lithium cuprates was optimized with 2,4-dimethoxypyrimidine and 2-methoxypyridine as the substrates and benzoyl chloride as the electrophile. [(tmp)2CuLi] (+2 LiCl) (tmp=2,2,6,6-tetramethylpiperidino) was identified as the best reagent and its use was extended to anisole, 1,4-dimethoxybenzene, other substituted pyridines, furan, thiophene and derivatives, and N-Boc-indole (Boc=tert-butyloxycarbonyl). Of the electrophiles employed to attempt the interception of the generated aryl cuprates, aroyl chlorides, iodomethane, and diphenyl disulfide efficiently reacted. In addition, different oxidative agents were identified to afford symmetrical biaryls. Finally, palladium-catalyzed coupling with aryl halides was optimized and allowed the synthesis of different aryl derivatives in medium to good yields.
- Nguyen, Tan Tai,Marquise, Nada,Chevallier, Floris,Mongin, Florence
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experimental part
p. 10405 - 10416
(2011/10/12)
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- Metal-free efficient, general and facile iododecarboxylation method with biodegradable co-products
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The development of a novel, efficient and robust method for the general conversion of aliphatic and aromatic carboxylic acids to organic iodides without the use of heavy metals or strong oxidizing agents is reported. Commercially available N-iodoamides were used for both initiation and halogen donation under irradiative conditions. Isolation of the product is extremely simple and the major co-product is removed as a water-soluble biodegradable material. Copyright
- Kulbitski, Kseniya,Nisnevich, Gennady,Gandelman, Mark
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supporting information; experimental part
p. 1438 - 1442
(2011/07/30)
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- Deprotonative metalation of substituted aromatics using mixed lithium-cobalt combinations
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The deprotonation of anisole was attempted using different homo- and heteroleptic TMP/Bu mixed lithium-cobalt combinations. Using iodine to intercept the metalated anisole, an optimization of the reaction conditions showed that in THF at room temperature 2 equiv of base were required to suppress the formation of the corresponding 2,2′-dimer. The origin of the dimer was not identified, but its formation was favored with allyl bromide as electrophile. The metalated anisole was efficiently trapped using iodine, anisaldehyde, and chlorodiphenylphosphine, and moderately employing benzophenone, and benzoyl chloride. 1,2-, 1,3-, and 1,4-dimethoxybenzene were similarly converted regioselectively to the corresponding iodides. It was observed that 2-methoxy- and 2,6-dimethoxypyridine were more prone to dimerization than the corresponding benzenes when treated similarly. Involving ethyl benzoate in the metalation-iodination sequence showed that the method was not suitable to functionalize substrates bearing reactive functions.
- Dayaker, Gandrath,Chevallier, Floris,Gros, Philippe C.,Mongin, Florence
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experimental part
p. 8904 - 8910
(2011/01/04)
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- Deprotonative metalation of substituted benzenes and heteroaromatics using amino/alkyl mixed lithium-zinc combinations
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Different homoleptic and heteroleptic lithium-zinc combinations were prepared, and structural elements obtained on the basis of NMR spectroscopic experiments and DFT calculations. In light of their ability to metalate anisole, pathways were proposed to justify the synergy observed for some mixtures. The best basic mixtures were obtained either by combining ZnCl 2·TMEDA (TMEDA = N,N,N',N'tetramethylethylenediamine) with [Li(tmp)] (tmp = 2,2,6,6-tetramethylpiperidino; 3 equiv) or by replacing one of the tmp in the precedent mixture with an alkyl group. The reactivity of the aromatic lithium zincates supposedly formed was next studied, and proved to be substrate-, base-, and electrophile-dependent. The aromatic lithium zincates were finally involved in palladium-catalyzed cross-coupling reactions with aromatic chlorides and bromides.
- Snegaroff, Katia,Komagawa, Shinsuke,Chevallier, Floris,Gros, Philippe C.,Golhen, Stephane,Roisnel, Thierry,Uchiyama, Masanobu,Mongin, Florence
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experimental part
p. 8191 - 8201
(2010/09/11)
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- Ortho-directed functionalization of arenes using magnesate bases
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Ortho-directed functionalisation of arenes using lithium alkylmagnesate bases were achieved, demonstrating the potential use of arylmagnesates as suitable arylanions, without a further transmetallation step, for challenging functionalizations such as fluorination, hydroxylation, arylation, vinylation and alkylation through epoxide ring-opening.
- Bellamy, Estelle,Bayh, Omar,Hoarau, Christophe,Trecourt, Francois,Queguiner, Guy,Marsais, Francis
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supporting information; experimental part
p. 7043 - 7045
(2010/11/02)
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- NO-CARRIER-ADDED NUCLEOPHILIC [F-18] FLUORINATION OF AROMATIC COMPOUNDS
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Phenyliodonium ylide derivatives substituted with electron donating as well as electron withdrawing groups on the aromatic ring are shown for use as precursors in aromatic nucleophilic substitution reactions. The iodonium ylide group is substituted by nucleophiles such as halide ions to provide the corresponding haloaryl derivatives. No- carrier-added [F-18]fluoride ion exclusively substitutes the iodonium ylide moiety in these derivatives and provides high specific activity F- 18 labeled fluoro derivatives. Protected L-dopa-6-iodonium ylide derivative have been synthesized as a precursors for the preparation of no-carrier-added 6-[F- 18]fluoro-L-dopa. The iodonium ylide group in this L-dopa.derivative is nucleophilically substituted by no-carrier-added [F-18]fluoride ion to provide a [F-18]fluoro intermediates which upon acid hydrolysis yielded 6-[F- 18]fluoro-L-dopa.
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Page/Page column 11-12
(2010/11/03)
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- METHOD OF PRODUCING IODIZING AGENT, AND METHOD OF PRODUCING AROMATIC IODINE COMPOUND
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A method of the present invention, for producing an iodizing agent, includes the step of electrolyzing iodine molecules in a solution by using an acid as a supporting electrolyte. This realizes (i) a method of producing an iodine cation suitable for use as an iodizing agent that does not require a sophisticated separation operation after iodizing reaction is completed, and (ii) an electrolyte used in the method. Further, a method of the present invention, for producing an aromatic iodine compound, includes the step of causing an iodizing agent, and an aromatic compound whose nucleus has one or more substituent groups and two or more hydrogen atoms, to react with each other under the presence of a certain ether compound. This realizes such a method of producing an aromatic iodine compound that position selectivity in iodizing reaction of an aromatic compound is improved.
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Page/Page column 10
(2010/05/13)
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- Deprotonative metalation of functionalized aromatics using mixed lithium-cadmium, lithium-indium, and lithium-zinc species
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In situ mixtures of CdCl2TMEDA (0.5 equiv; TMEDA = N,N,N',N'-tetramethylethylenediamine) or InCl3 (0.33 equiv) with [Li(tmp)] (tmp = 2,2,6,6-tetramethylpiperidino; 1.5 or 1.3 equiv, respectively) were compared with the previously described mixture of ZnCl2-TMEDA (0.5 equiv) and [Li(tmp)] (1.5 equiv) for their ability to deprotonate anisole, benzothiazole, and pyrimidine. [(tmp)3CdLi] proved to be the best base when used in tetrahydrofuran at room temperature, as demonstrated by subsequent trapping with iodine. The Cd-Li base then proved suitable for the metalation of a large range of aromatics including benzenes bearing reactive functional groups (CONEt2, CO2Me, CN, COPh) or heavy halogens (Br, I), and heterocycles (from the furan, thiophene, pyrrole, oxazole, thiazole, pyridine, and diazine series). Fivemembered heterocycles benefiting from doubly activated positions were similarly dideprotonated at room temperature. The aromatic lithium cadmates thus obtained were involved in palladium-catalyzed cross-coupling reactions or simply quenched with acid chlorides.
- Snegaroff, Katia,L'Helgoual'ch, Jean-Martial,Bentabed-Ababsa, Ghenia,Nguyen, Tan Tai,Chevallier, Floris,Yonehara, Mitsuhiro,Uchiyama, Masanobu,Derdour, Aicha,Mongin, Florence
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experimental part
p. 10280 - 10290
(2010/04/24)
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- New Gilman-type lithium cuprate from a copper(II) salt: synthesis and deprotonative cupration of aromatics
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Deprotonative cupration of aromatics including heterocycles (anisole, 1,4-dimethoxybenzene, thiophene, furan, 2-fluoropyridine, 2-chloropyridine, 2-bromopyridine, and 2,4-dimethoxypyrimidine) was realized in tetrahydrofuran at room temperature using the Gilman-type amido-cuprate (TMP)2CuLi in situ prepared from CuCl2·TMEDA through successive addition of 1 equiv of butyllithium and 2 equiv of LiTMP. The intermediate lithium (hetero)arylcuprates were evidenced by trapping with iodine, allyl bromide, methyl iodide, and benzoyl chlorides, the latter giving the best results. Symmetrical dimers were also prepared from lithium azine and diazine cuprates using nitrobenzene as an oxidative agent.
- Nguyen, Tan Tai,Chevallier, Floris,Jouikov, Viatcheslav,Mongin, Florence
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experimental part
p. 6787 - 6790
(2010/04/29)
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- Deprotonative cadmation of functionalized aromatics
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This communication describes the deproto-metalation of a large range of aromatics including heterocycles using a newly developed lithium-cadmium base; the reaction proceeds at room temperature with an excellent chemoselectivity and efficiency, and proved to be regioselective in most cases. The Royal Society of Chemistry.
- L'Helgoual'ch, Jean-Martial,Bentabed-Ababsa, Ghenia,Chevallier, Floris,Yonehara, Mitsuhiro,Uchiyama, Masanobu,Derdour, Aicha,Mongin, Florence
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supporting information; experimental part
p. 5375 - 5377
(2009/03/11)
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