- Connecting binuclear Pd(III) and mononuclear Pd(IV) chemistry by Pd-Pd bond cleavage
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Oxidation of binuclear Pd(II) complexes with PhICl2 or PhI(OAc)2 has previously been shown to afford binuclear Pd(III) complexes featuring a Pd-Pd bond. In contrast, oxidation of binuclear Pd(II) complexes with electrophilic trifluoromethylating ("CF3 +") reagents has been reported to afford mononuclear Pd(IV) complexes. Herein, we report experimental and computational studies of the oxidation of a binuclear Pd(II) complex with "CF3 +" reagents. These studies suggest that a mononuclear Pd(IV) complex is generated by an oxidation-fragmentation sequence proceeding via fragmentation of an initially formed, formally binuclear Pd(III), intermediate. The observation that binuclear Pd(III) and mononuclear Pd(IV) complexes are accessible in the same reactions offers an opportunity for understanding the role of nuclearity in both oxidation and subsequent C-X bond-forming reactions.
- Powers, David C.,Lee, Eunsung,Ariafard, Alireza,Sanford, Melanie S.,Yates, Brian F.,Canty, Allan J.,Ritter, Tobias
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Read Online
- Pd/Cu-Catalyzed Vinylation of Terminal Alkynes with (2-Bromoethyl)diphenylsulfonium Triflate
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The potential of (2-bromoethyl)diphenylsulfonium triflate to be a powerful vinylation reagent was determined by the Sonogashira cross-coupling reactions with terminal alkynes. The vinylation proceeded smoothly at 25 °C under Pd/Cu catalysis to afford a variety of 1- and 2-unsubstituted 1,3-enynes in moderate to excellent yields. This protocol represents the first application of (2-haloethyl)diphenylsulfonium triflate as a CH═CH2 transfer source in organic synthesis.
- Ming, Xiao-Xia,Wu, Shuai,Tian, Ze-Yu,Song, Jia-Wei,Zhang, Cheng-Pan
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supporting information
p. 6795 - 6800
(2021/09/08)
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- Mechanochemical-Cascaded C-N Cross-Coupling and Halogenation Using N-Bromo- And N-Chlorosuccinimide as Bifunctional Reagents
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Exploration of alternative energy sources for chemical transformations has gained significant interest from chemists, and mechanochemistry is one of those sources. Herein, we report the use of N-bromosuccinimides (NBS) and N-chlorosuccinimides (NCS) as bifunctional reagents for a cascaded C-N bond formation and subsequent halogenation reactions. Under the solvent-free mechanochemical (ball-milling) conditions, the synthesis of a wide range of phenanthridinone derivatives from N-methoxy-[1,1′-biphenyl]-2-carboxamides is accomplished. During the reactions, NBS and NCS first assisted the oxidative C-N coupling reaction and subsequently promoted a halogenation reaction. Thus, the role of NBS and NCS was established to be bifunctional. Overall, a mild, solvent-free, convenient, one-pot, and direct synthesis of various bromo- and chloro-substituted phenanthridinone derivatives was achieved.
- Bera, Shyamal Kanti,Mal, Prasenjit
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p. 14144 - 14159
(2021/09/13)
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- Method for preparing iodo-benzoic acid (ester) by improving moral Michael reaction
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The invention discloses a method for preparing iodo-benzoic acid (ester) by improving a moral reaction, and belongs to the technical field of organic synthesis. The method comprises the following steps: preparing and separating the diazonium tetrafluoroborate through diazotization of aminobenzoic acid (ester) and then performing iodination reaction with the iodinated reagent in an organic medium to obtain the corresponding iodo carboxylic acid (ester). The iodo-benzoic acid (ester) prepared by the method has high purity. The method has the advantages of good quality and simple post-treatment, and the product yield reaches 70 - 90%.
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Paragraph 0024; 0027-0030
(2021/11/03)
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- Lipshutz-type bis(amido)argentates for directed: Ortho argentation
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Bis(amido)argentate (TMP)2Ag(CN)Li2 (3, TMP-Ag-ate; TMP = 2,2,6,6-tetramethylpiperidido) was designed as a tool for chemoselective aromatic functionalization via unprecedented directed ortho argentation (DoAg). X-Ray crystallographic analysis showed that 3 takes a structure analogous to that of the corresponding Lipshutz cuprate. DoAg with this TMP-Ag-ate afforded multifunctional aromatics in high yields in processes that exhibited high chemoselectivity and compatibility with a wide range of functional groups. These included organometallics- A nd transition metal-susceptible substituents such as methyl ester, aldehyde, vinyl, iodo, (trifluoromethanesulfonyl)oxy and nitro groups. The arylargentates displayed good reactivity with various electrophiles. Chalcogen (S, Se, and Te) installation and azo coupling reactions also proceeded efficiently.
- Tezuka, Noriyuki,Hirano, Keiichi,Peel, Andrew J.,Wheatley, Andrew E. H.,Miyamoto, Kazunori,Uchiyama, Masanobu
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p. 1855 - 1861
(2020/03/03)
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- Development of Novel N-hydroxypyridone Derivatives as Potential Anti-Ischemic Stroke Agents
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Our previous study had identified ciclopirox (CPX) as a promising lead compound for treatment of ischemic stroke. To find better neuroprotective agents, a series of N-hydroxypyridone derivatives based on CPX were designed, synthesized, and evaluated in this study. Among these derivatives, compound 11 exhibits significant neuroprotection against oxygen glucose deprivation and oxidative stress-induced injuries in neuronal cells. Moreover, compound 11 possesses good blood-brain barrier permeability and superior antioxidant capability. In addition, a complex of compound 11 with olamine-11·Ola possesses good water solubility, negligible hERG inhibition, and superior metabolic stability. The in vivo experiment demonstrates that 11·Ola significantly reduces brain infarction and alleviates neurological deficits in middle cerebral artery occlusion rats. Hence, compound 11·Ola is identified in our research as a prospective prototype in the innovation of stroke treatment.
- Hu, Linghao,Feng, Hongxuan,Zhang, Hongguang,Yu, Songda,Zhao, Qinyuan,Wang, Wei,Bao, Fengxia,Ding, Xun,Hu, Jiajing,Wang, Manjiong,Xu, Yixiang,Wu, Zengrui,Li, Xiaokang,Tang, Yun,Mao, Fei,Chen, Xiaoyan,Zhang, Haiyan,Li, Jian
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p. 1051 - 1067
(2020/03/10)
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- Reconciling Electrostatic and n→π* Orbital Contributions in Carbonyl Interactions
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Interactions between carbonyl groups are prevalent in protein structures. Earlier investigations identified dominant electrostatic dipolar interactions, while others implicated lone pair n→π* orbital delocalisation. Here these observations are reconciled.
- Adam, Catherine,Borsley, Stefan,Cockroft, Scott L.,Ling, Kenneth B.,Mati, Ioulia K.,Muchowska, Kamila B.,Nichol, Gary S.,Pascoe, Dominic J.,Smolyar, Ivan V.
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supporting information
p. 14602 - 14608
(2020/07/06)
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- Transition-Metal-Free Synthesis of Phenanthridinones through Visible-Light-Driven Oxidative C–H Amidation
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The treatment of N-aryl biphenylcarboxamide, 1-chloroanthraquinone (1-Cl-AQN) catalyst, and K2CO3 in CHCl3 under visible light irradiation affords phenanthridinone via radical cyclization. This reaction proceeds under transition-metal-free condition, room temperature, and direct C–H amidation. Mechanistic studies indicate that amidyl radical generation proceeds by visible light induced proton coupled electron transfer (PCET) from N–H bond of the amide.
- Usami, Kaoru,Yamaguchi, Eiji,Tada, Norihiro,Itoh, Akichika
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p. 1496 - 1504
(2019/06/27)
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- Generation of Organozinc Reagents by Nickel Diazadiene Complex Catalyzed Zinc Insertion into Aryl Sulfonates
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The generation of arylzinc reagents (ArZnX) by direct insertion of zinc into the C?X bond of ArX electrophiles has typically been restricted to iodides and bromides. The insertions of zinc dust into the C?O bonds of various aryl sulfonates (tosylates, mesylates, triflates, sulfamates), or into the C?X bonds of other moderate electrophiles (X=Cl, SMe) are catalyzed by a simple NiCl2–1,4-diazadiene catalyst system, in which 1,4-diazadiene (DAD) stands for diacetyl diimines, phenanthroline, bipyridine and related ligands. Catalytic zincation in DMF or NMP solution at room temperature now provides arylzinc sulfonates, which undergo typical catalytic cross-coupling or electrophilic substitution reactions.
- Klein, Philippe,Lechner, Vivien Denise,Schimmel, Tanja,Hintermann, Lukas
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supporting information
p. 176 - 180
(2019/12/11)
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- Nickel-catalyzed regioselective C-H halogenation of electron-deficient arenes
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A straightforward Ni(ii)-catalyzed general strategy was developed for the ortho-halogenation of electron-deficient arenes with easily available halogenating reagents N-halosuccinimides (NXS; X = Br, Cl and I). The transformation was highly regioselective and a wide substrate scope and functional group tolerance were observed. This discovery could be of great significance for the selective halogenation of amides, benzoic esters and other substances with guiding groups. Mechanistic investigations were also described.
- Li, Ze-Lin,Wu, Peng-Yu,Cai, Chun
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supporting information
p. 3462 - 3468
(2019/02/25)
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- NOVEL NUCLEIC ACID MODIFIERS
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The present inventions generally relate to site-specific delivery of nucleic acid modifiers and includes novel DNA-binding proteins and effectors that can be rapidly programmed to make site-specific DNA modifications. The present inventions also provide a synthetic all-in-one genome editor (SAGE) systems comprising designer DNA sequence readers and a set of small molecules that induce double-strand breaks, enhance cellular permeability, inhibit NHEJ and activate HDR, as well as methods of using and delivering such systems.
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- p-TSA-Based DESs as “Active Green Solvents” for Microwave Enhanced Cyclization of 2-Alkynyl-(hetero)-arylcarboxylates: an Alternative Access to 6-Substituted 3,4-Fused 2-Pyranones
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In this paper, we describe the use of p-TSA based Deep Eutectic Solvents (DESs) as alternative environmental-friendly “active” solvents for the microwave-mediated synthesis of 6-substituted 3,4-fused 2-pyranones, and in particular isocoumarins, starting from 2-alkynyl-(hetero)arylcarboxylates. When the alkyne terminus bears a neutral or an electron-donating group (EDG), the reactions are fast, clean and highly regioselective, to give the 6-endo-dig cyclization products in good to excellent yields. For substrates bearing an electron-withdrawing group (EWG) on the alkyne end, the regioselectivity can be tuned by adding a small amount of silver(I) triflate as co-catalyst. DES was demonstrated to be reusable without loss of efficiency in terms of reaction yields. Based on experimental evidence and previous findings, two competitive mechanisms working simultaneously are proposed to explain the outcomes and the regioselectivity issues.
- Curti, Fabiola,Tiecco, Matteo,Pirovano, Valentina,Germani, Raimondo,Caselli, Alessandro,Rossi, Elisabetta,Abbiati, Giorgio
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p. 1904 - 1914
(2019/02/26)
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- Gold-catalyzed Rapid Construction of Nitrogen-containing Heterocyclic Compound Library with Scaffold Diversity and Molecular Complexity
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1,3-unsubstituted 2-(1H-indol-2-yl)ethanamines were employed for the first time to react with alkynoic acids (AAs) to achieve gold-catalyzed highly selective cascade reactions to furnish novel indole-fused skeletons. Furthermore, with this powerful gold catalytic system, a library of indole/pyrrole/thiophene/benzene/naphthalene/pyridine-based nitrogen-containing heterocyclic compounds (NCHCs) with scaffold diversity and molecular complexity was constructed rapidly using various amine nucleophiles (ANs) and diverse AAs as the building blocks. This general protocol features excellent selectivity, extraordinarily broad substrate scope, readily available inputs, good to high yields, high bond-forming efficiency, and step economy, thus providing a facile and efficient access to a variety of valuable nitrogen-containing heterocycles.
- Qiao, Jin,Jia, Xiuwen,Li, Pinyi,Liu, Xiaoyan,Zhao, Jingwei,Zhou, Yu,Wang, Jiang,Liu, Hong,Zhao, Fei
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- 1,3-Dibromo-5,5-dimethylhydantoin as a Precatalyst for Activation of Carbonyl Functionality
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Activation of carbonyl moiety is one of the most rudimentary approaches in organic synthesis and is crucial for a plethora of industrial-scale condensation reactions. In esterification and aldol condensation, which represent two of the most important reactions, the susceptibility of the carbonyl group to nucleophile attack allows the construction of a variety of useful organic compounds. In this context, there is a constant need for development of and improvement in the methods for addition-elimination reactions via activation of carbonyl functionality. In this paper, an advanced methodology for the direct esterification of carboxylic acids and alcohols, and for aldol condensation of aldehydes using widely available, inexpensive, and metal-free 1,3-dibromo-5,5-dimethylhydantoin under neat reaction conditions is reported. The method is air- and moisture-tolerant, allowing simple synthetic and isolation procedures for both reactions presented in this paper. The reaction pathway for esterification is proposed and a scale-up of certain industrially important derivatives is performed.
- ?ebular, Klara,Bo?i?, Bojan ?.,Stavber, Stojan
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supporting information
(2019/08/01)
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- Metal-Free Synthesis of 4-Chloroisocoumarins by TMSCl-Catalyzed NCS-Induced Chlorinative Annulation of 2-Alkynylaryloate Esters
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4-Chloroisocoumarins can be conveniently prepared from 2-alkynylaryloate esters via the activation of alkynes by electrophilic chlorine, generated in situ from N-chlorosuccinimide (NCS) in the presence of 10 mol % trimethylsilyl chloride (TMSCl), which leads to 6-endo-dig-selective chlorinative annulation to give the desired products in moderate to quantitative yields. The procedure employs readily available reagents and can be conveniently carried out on a wide scope of substrates under mild conditions (0 °C to rt). Furthermore, the reaction is scalable for gram-scale preparation of 4-chloroisocoumarins. Additionally, 4-bromo- and 4-iodoisocoumarins can be prepared in moderate to good yields by replacing NCS with N-bromosuccinimide (NBS) and N-iodosuccinimide (NIS), respectively.
- Norseeda, Krissada,Chaisan, Nattawadee,Thongsornkleeb, Charnsak,Tummatorn, Jumreang,Ruchirawat, Somsak
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p. 16222 - 16236
(2019/12/25)
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- Synthesis of 5H-Selenopheno[3,2-c]isochromen-5-ones Promoted by Dialkyl Diselenides and Oxone
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We describe here for the first time the synthesis of isochromenones fused to selenophenes. 5H-Selenopheno[3,2-c]isochromen-5-ones were obtained through a double intramolecular cyclization of methyl 2-(organyl-1,3-diynyl)benzoate promoted by electrophilic species of selenium generated in situ by the reaction of dialkyl diselenides with Oxone, using ethanol as solvent. The reactions were conducted satisfactorily under mild conditions, using a range of 1,3-diynes and dialkyl diselenides as substrates. A total of sixteen unprecedent 5H-selenopheno[3,2-c]isochromen-5-ones were selectively obtained in moderate to good yields (40–86%) under reflux in an open flask and in short reaction times (1.0–2.5 h). (Figure presented.).
- Goulart, Helen A.,Neto, José S. S.,Barcellos, Angelita M.,Barcellos, Thiago,Silva, Márcio S.,Alves, Diego,Jacob, Raquel G.,Lenard?o, Eder J.,Perin, Gelson
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supporting information
p. 3403 - 3411
(2019/05/28)
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- A new alkylation of aryl alcohols by boron trifluoride etherate
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The ethylation of aryl alcohols by an ethyl moiety of boron trifluoride etherate is described. The reaction proceeded cleanly and afforded good yields of the corresponding aryl ethyl ethers. It tolerated the presence of functional groups such as aryl, alkyl, halogens, nitro, nitrile, and amino. However, the presence of amino or nitro groups ortho to a hydroxyl group of an aryl compound drastically reduced the yields of the anticipated products due to the chelation of the aforementioned functional groups with boron trifluoride etherate. A nitrogen atom in the aromatic ring system, as exemplified by hydroxypyridine and 8-hydroxyquinoline, completely inhibited the reaction. Resorcinol, hydroquinone, and aryl alcohols with aldehyde functions decomposed under the reaction conditions.
- Jumbam, Ndze Denis,Maganga, Yamkela,Masamba, Wayiza,Mbunye, Nomthandazo I.,Mgoqi, Esethu,Mtwa, Sphumusa
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- Silver triflate/: P -TSA co-catalysed synthesis of 3-substituted isocoumarins from 2-alkynylbenzoates
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In this paper, we describe the silver triflate/p-toluenesulfonic acid co-catalysed synthesis of seventeen isocoumarins and two thieno[2,3-c]pyran-7-ones starting from 2-alkynylbenzoates and 3-alkynylthiophene-2-carboxylates, respectively. The reaction proceeds with absolute regioselectivity under mild reaction conditions and low catalyst loading, to afford the desired products in good to excellent yields. A conceivable reaction mechanism is proposed and supported by isotope-exchange tests, 1H NMR studies and ad hoc experiments.
- Gianni, Jonathan,Pirovano, Valentina,Abbiati, Giorgio
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supporting information
p. 3213 - 3219
(2018/05/17)
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- Radical C?H-Amination of Heteroarenes using Dual Initiation by Visible Light and Iodine
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A novel light-induced C?H amination of heteroarenes can be accomplished with preformed iodine(III) reagents as the combined oxidant and nitrogen source. The reaction requires the use of a small amount of molecular iodine, which under photochemical activation generates in situ an iodine(I) reagent as the initiator of the radical amination reaction. A total of 32 examples exemplify the broad scope of the transformation. (Figure presented.).
- Lucchetti, Nicola,Tkacheva, Anastasia,Fantasia, Serena,Mu?iz, Kilian
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supporting information
p. 3889 - 3893
(2018/09/21)
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- ISOQUINOLINE DERIVATIVES AS PERK INHIBITORS
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The invention is directed to substituted isoquinoline derivatives and uses thereof. Specifically, the invention is directed to compounds according to Formula I and the use of compounds of Formula (I) in treating disease states: (I) wherein R1,
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Page/Page column 80-81
(2018/02/17)
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- Efficient synthesis of esters through oxone-catalyzed dehydrogenation of carboxylic acids and alcohols
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Since esters are important organic synthesis intermediates, an environmentally friendly oxone catalyzed-esterification of carboxylic acids with alcohols has been developed. A series of carboxylic acid esters are obtained in high yield. This strategy requires mild reaction conditions, providing an attractive alternative for the construction of valuable carbonyl esters. Electron-rich and electron-deficient groups are compatible with the standard conditions and a variety of substrates are demonstrated. Moreover, the reaction could easily be adapted to typical prodrugs, drugs and gram-scale synthesis.
- Hou, Fei,Wang, Xi-Cun,Quan, Zheng-Jun
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supporting information
p. 9472 - 9476
(2019/01/03)
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- Esterification of aryl/alkyl acids catalysed by n-bromosuccinimide under mild reaction conditions
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N-halosuccinimides (NXSs) are well-known to be convenient, easily manipulable and low-priced halogenation reagents in organic synthesis. In the present work, N-bromosuccinimide (NBS) has been promoted as the most efficient and selective catalyst among the NXSs in the reaction of direct esterification of aryl and alkyl carboxylic acids. Comprehensive esterification of substituted benzoic acids, mono-, di- and tri-carboxy alkyl derivatives has been performed under neat reaction conditions. The method is metal-free, air- and moisture-tolerant, allowing for a simple synthetic and isolation procedure as well as the large-scale synthesis of aromatic and alkyl esters with yields up to 100%. Protocol for the recycling of the catalyst has been proposed.
- ?ebular, Klara,Bo?i?, Bojan ?.,Stavber, Stojan
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- Structural design, synthesis and substituent effect of hydrazone-N-acylhydrazones reveal potent immunomodulatory agents
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4-(Nitrophenyl)hydrazone derivatives of N-acylhydrazone were synthesized and screened for suppress lymphocyte proliferation and nitrite inhibition in macrophages. Compared to an unsubstituted N-acylhydrazone, active compounds were identified within initial series when hydroxyl, chloride and nitro substituents were employed. Structure-activity relationship was further developed by varying the position of these substituents as well as attaching structurally-related substituents. Changing substituent position revealed a more promising compound series of anti-inflammatory agents. In contrast, an N-methyl group appended to the 4-(nitrophenyl)hydrazone moiety reduced activity. Anti-inflammatory activity of compounds is achieved by modulating IL-1β secretion and prostaglandin E2 synthesis in macrophages and by inhibiting calcineurin phosphatase activity in lymphocytes. Compound SintMed65 was advanced into an acute model of peritonitis in mice, where it inhibited the neutrophil infiltration after being orally administered. In summary, we demonstrated in great details the structural requirements and the underlying mechanism for anti-inflammatory activity of a new family of hydrazone-N-acylhydrazone, which may represent a valuable medicinal chemistry direction for the anti-inflammatory drug development in general.
- Meira, Cássio S.,dos Santos Filho, José Maurício,Sousa, Caroline C.,Anjos, Pamela S.,Cerqueira, Jéssica V.,Dias Neto, Humberto A.,da Silveira, Rafael G.,Russo, Helena M.,Wolfender, Jean-Luc,Queiroz, Emerson F.,Moreira, Diogo R.M.,Soares, Milena B.P.
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p. 1971 - 1985
(2018/03/12)
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- Protection of COOH and OH groups in acid, base and salt free reactions
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We report an iron-catalyzed general functional group protection method with inexpensive reagents. This environmentally benign process does not use acids or bases, and does not produce waste products. Further purification beyond filtration and evaporation is, in most cases, unnecessary. Free COOH and OH groups can be protected in a one-pot reaction.
- Zhu, Xiaotao,Qian, Bo,Wei, Rongbiao,Huang, Jian-Dong,Bao, Hongli
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supporting information
p. 1444 - 1447
(2018/04/12)
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- Direct Pd(II)-Catalyzed Site-Selective C5-Arylation of 2-Pyridone Using Aryl Iodides
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A straightforward Pd(II)-catalyzed general strategy was developed for the C5-selective arylation of the 2-pyridone core with easily available aryl iodides. The transformation was highly regioselective and accomplished with a wide scope and functional group tolerance. Silver nitrate played a crucial role in this direct site-selective arylation. The method was extended to synthesize biologically active molecules.
- Maity, Saurabh,Das, Debapratim,Sarkar, Souradip,Samanta, Rajarshi
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supporting information
p. 5167 - 5171
(2018/09/13)
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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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- Synthesis, Characterization, and Reaction of a Both Inter- and Intramolecularly Coordinated Pseudocyclic Iodosylbenzene–Trifluoroacetic Acid Complexes
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An ortho-substituted ether-oxygen-coordinated pseudocyclic iodosylbenzene-trifluoroacetic acid (pcISB-TFA) complex was synthesized and characterized by X-ray crystallographic analysis. TFA suppresses the disproportionation by both coordination of the oxygen atom to the iodine(III) center through secondary bonding and by hydrogen bonding to the oxygen anion. This bench-stable reagent is highly soluble in common organic solvents and reacts with various organic substrates under mild reaction conditions to give the corresponding products in good yields.
- Yudasaka, Masaharu,Maruyama, Toshifumi,Yamaguchi, Eiji,Tada, Norihiro,Itoh, Akichika
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p. 550 - 556
(2018/02/09)
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- BROAD SPECTRUM ANTIVIRAL COMPOUNDS AND USES THEREOF
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Disclosed herein, inter alia, are agents having antiviral activity and methods of use thereof.
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- Efficient copper-catalyzed Sonogashira coupling reactions and simulation studies
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A practical copper-catalyzed I-substitutions of alkyl-2-iodobenzoates with alkynes have been developed using Cu powder as a catalyst under solvent, cocatalyst, and base-free conditions. This reaction system is new, facile, efficient, and economical that g
- Ali, Imran,Nighot, Dnyaneshwar,Lone, Mohammad Nadeem,Jain, Arvind
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supporting information
p. 1175 - 1184
(2017/06/09)
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- Stoichiometric and Catalytic C?C and C?H Bond Formation with B(C6F5)3 via Cationic Intermediates
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This work showcases a new catalytic cyclization reaction using a highly Lewis acidic borane with concomitant C?H or C?C bond formation. The activation of alkyne-containing substrates with B(C6F5)3 enabled the first catalytic intramolecular cyclizations of carboxylic acid substrates using this Lewis acid. In addition, intramolecular cyclizations of esters enable C?C bond formation as catalytic B(C6F5)3 can be used to effect formal 1,5-alkyl migrations from the ester functional groups to unsaturated carbon–carbon frameworks. This metal-free method was used for the catalytic formation of complex dihydropyrones and isocoumarins in very good yields under relatively mild conditions with excellent atom efficiency.
- Soltani, Yashar,Wilkins, Lewis C.,Melen, Rebecca L.
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supporting information
p. 11995 - 11999
(2017/09/20)
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- Development and Application of a Recyclable High-Load Magnetic Co/C Hybrid ROMP-Derived Benzenesulfonyl Chloride Reagent and Utility of Corresponding Analogues
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The development and application of high-load, recyclable magnetic Co/C hybrid ROMP-derived benzenesulfonyl chloride and analogues is reported. The regeneration and utility of these reagents in the methylation/alkylation of various carboxylic acids is demonstrated via efficient retrieval of the magnetic reagent with a neodymium magnet. Additional reactions employing the analogue sulfonic acid and in situ generated magnetic benzenesulfonyl azide are also reported.
- Faisal, Saqib,Zang, Qin,Maity, Pradip K.,Brandhofer, Agnes,Kearney, Patrick C.,Reiser, Oliver,Grass, Robert N.,Stoianova, Diana,Hanson, Paul R.
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supporting information
p. 2274 - 2277
(2017/05/12)
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- Iron(III)/TEMPO-Catalyzed Synthesis of 2,5-Disubstituted 1,3,4-Oxadiazoles by Oxidative Cyclization under Mild Conditions
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A simple and efficient cationic Fe(III)/TEMPO-catalyzed oxidative cyclization of aroyl hydrazones has been developed for the synthesis of 2,5-disubstituted 1,3,4-oxadiazole derivatives. The reaction offers a broad scope, good functional-group tolerance, and high yields under mild conditions in the presence of O 2.
- Zhang, Guofu,Yu, Yidong,Zhao, Yiyong,Xie, Xiaoqiang,Ding, Chengrong
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supporting information
p. 1373 - 1377
(2017/06/27)
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- Production technology of methyl 2-iodobenzoate
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Methyl 2-iodobenzoate is an important chemical product. Production technology is sketched, comprising: adding a certain amount of methyl anthranilate, sodium nitrite, and 98.3% of sulfuric acid for a diazotization reaction, carrying out a separation process to generate a waste liquid after the reaction is completed, adding a certain amount of a potassium iodide aqueous solution for a substitution reaction after the separation is over, wherein exhaust gas is generated in the substitution reaction process, performing centrifugation after the substitution reaction is completed, separating a water-insoluble product from a master supernatant, outputting the supernatant as waste water, using 10% of sodium sulfite to wash the product after the separation is completed, wherein waste water is generated in a washing process, performing rectification after the product is cleaned, and outputting the distillate as a final product and the distillation residue as a waste liquid.
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Paragraph 0001
(2017/06/02)
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- A method of manufacturing a fluorene derivative (by machine translation)
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PROBLEM TO BE SOLVED: To provide an economically and industrially advantageous method of producing 9-fluorenone and its derivatives on an industrial scale.SOLUTION: An economically and industrially advantageous method of producing 9-fluorenone and its derivatives comprises carrying out an intramolecular cyclization reaction of a biaryl carboxylic acid and its derivative in the presence of a rhodium salt and/or a rhodium complex and an acid anhydride. The efficiency of production of the compounds is improved further by adding an alkali metal halide or 1,2-bis(diphenylphosphino)ethane in the intramolecular cyclization reaction.
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Paragraph 0028
(2020/02/26)
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- Regiodivergent Iodocyclizations for the Highly Diastereoselective Synthesis of syn - And anti -Hydroxyl-Isochromanones and -Isobenzofuranones: Concise Synthesis of the Isochromanone Core of the Ajudazols
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An efficient synthetic strategy to access hydroxyl-isochromanone and -isobenzofurans from readily available joint alkene precursors by a regiodivergent one-pot iodocyclization-substitution tandem process is reported. The cyclizations proceed with excellen
- Thiede, Sebastian,Winterscheid, Peter Maria,Hartmann, Jan,Schnakenburg, Gregor,Essig, Sebastian,Menche, Dirk
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p. 697 - 709
(2016/03/01)
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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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- Silver-Mediated 18F-Labeling of Aryl-CF3 and Aryl-CHF2 with 18F-Fluoride
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We report the synthesis of [18F]arylCF3 and [18F]arylCHF2 derivatives from arylCF2Br and arylCHFCl precursors applying a silver-mediated halogen exchange with [18F]fluoride. In the absence of Ag(I)OTf, no reaction takes place at room temperature for both classes of substrates; this result demonstrates the beneficial role of silver(I) as a means to induce 18F-incorporation under very mild conditions.
- Verhoog, Stefan,Pfeifer, Lukas,Khotavivattana, Tanatorn,Calderwood, Samuel,Collier, Thomas Lee,Wheelhouse, Katherine,Tredwell, Matthew,Gouverneur, Véronique
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supporting information
p. 25 - 28
(2015/12/26)
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- Indium-Catalyzed Reductive Sulfidation of Esters by Using Thiols: An Approach to the Diverse Synthesis of Sulfides
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A new reductive preparation of unsymmetrical sulfides from esters and thiols in the presence of InI3 and either 1,1,3,3-tetramethyldisiloxane (TMDS) or PhSiH3 as the reductant was developed. This protocol was applied to not only benzoic acid esters that have a methoxy, methyl, chloro, bromo, iodo, or trifluoromethyl group on the aromatic ring but also aliphatic acid esters with either aromatic or aliphatic thiols. A reaction mechanism is proposed by using Hammett plot results and several control experiments. The reductive preparation of unsymmetrical sulfides from esters and thiols by using InI3 and either 1,1,3,3-tetramethyldisiloxane (TMDS) or PhSiH3 was developed. Several mechanistic studies support that the present transformation proceeds through O,S-and S,S-acetals as the reaction intermediates. TMDS = 1,1,3,3-tetramethyldisiloxane, R = aliphatic group.
- Miyazaki, Takahiro,Kasai, Shinsei,Ogiwara, Yohei,Sakai, Norio
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supporting information
p. 1043 - 1049
(2016/03/01)
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- Formation of substituted 1-naphthols and related products via dimerization of alkyl 3-(o-halo(het)aryl)-oxopropanoates based on a CuI-catalyzed domino C-arylation/condensation/aromatization process
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Substrates bearing both a β-ketoester moiety and a (het)aryl halide structure element were dimerized to 1-naphthols and related products in the presence of catalytic amounts of CuI in isopropanol. The reaction starts with an intermolecular C-arylation, which is followed by an intramolecular condensation. The final aromatization delivers the highly substituted products with yields up to 81%.
- Weischedel, Heike,Sudheendran, Kavitha,Mikhael, Alevtina,Conrad, Jürgen,Frey, Wolfgang,Beifuss, Uwe
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p. 3454 - 3467
(2016/06/06)
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- Nickel(II)-Mediated Regioselective C H Monoiodination of Arenes and Heteroarenes by using Molecular Iodine
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The 8-aminoquinoline-directed, nickel(II)-mediated ortho-iodination of benzamides using molecular iodine has been developed. The process is highly regioselective and furnishes only monoiodinated products. A broad range of arenes and heteroarenes with diverse functional groups provided monoiodinated products in good to excellent yields. (Figure presented.) .
- Khan, Bhuttu,Kant, Ruchir,Koley, Dipankar
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p. 2352 - 2358
(2016/07/28)
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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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- An enantioselective formal synthesis of montelukast sodium
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A formal synthesis of the antiasthma drug montelukast sodium is described, wherein the key chiral diol intermediate was accessed with greater convergence of the C-C bond-forming steps as compared to previous routes. Improved synthetic efficiency was achie
- Bollikonda, Satyanarayana,Mohanarangam, Saravanan,Jinna, Rajender Reddy,Kandirelli, Venkata Kiran Kumar,Makthala, Laxman,Sen, Saikat,Chaplin, David A.,Lloyd, Richard C.,Mahoney, Thomas,Dahanukar, Vilas Hareshwar,Oruganti, Srinivas,Fox, Martin E.
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p. 3891 - 3901
(2015/06/02)
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- Ultrasound-Assisted Methyl Esterification of Carboxylic Acids ACatalyzed by Polymer-Supported Triphenylphosphine
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A convenient and efficient sonochemical method for methyl esterification of carboxylic acids catalyzed by polymer-supported triAphenylphosphine (PS-Ph3P) is reported. In the presence of 1:0.1:2 molar ratio of 2,4,6-trichloro-1,3,5-triazine/PS-Ph3P/Na2CO3, methyl esters of various carboxylic acids bearing reactive hydroxyl groups as well as acid-or base-labile functionalities could be rapidly prepared (within 10-20 min) in good to excellent yields without necessity to pre-activate the acids. Using the polymer-bound phosphine also allows easy isolation of the products which, in most of the cases, were obtained in high purities without column chromatography.
- Jaita, Subin,Phakhodee, Wong,Pattarawarapan, Mookda
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p. 2006 - 2008
(2015/09/01)
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- Metal-free, room-temperature, radical alkoxycarbonylation of aryldiazonium salts through visible-light photoredox catalysis
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The first radical alkoxycarboxylation of aryldiazonium salts using CO gas through visible-light-induced photoredox catalysis (16 W blue LEDs) has been developed. This reaction is entirely metal-free, is carried out at room temperature with a low loading of an organic dye as a photocatalyst (0.5 mol%), and provides a wide range of arylcarboxylic acid esters in high yields. Importantly, this photocatalytic system can be successfully extended to other carboxylation reactions.
- Guo, Wei,Lu, Liang-Qiu,Wang, Yue,Wang, Ya-Ni,Chen, Jia-Rong,Xiao, Wen-Jing
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supporting information
p. 2265 - 2269
(2015/02/19)
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- Efficient synthesis of novel glutamate homologues and investigation of their affinity and selectivity profile at ionotropic glutamate receptors
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A convenient synthesis of four new enantiomerically pure acidic amino acids is reported and their affinity at ionotropic glutamate receptors was determined. The new compounds are higher homologues of glutamic acid in which the molecular complexity has bee
- Pinto, Andrea,Tamborini, Lucia,Mastronardi, Federica,Ettari, Roberta,Romano, Diego,Nielsen, Birgitte,De Micheli, Carlo,Conti, Paola
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supporting information
p. 1980 - 1982
(2014/04/17)
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- Synthesis of pyrrolo-/indolo[1,2-a ]quinolines and naphtho[2,1- b ]thiophenes from gem -dibromovinyls and sulphonamides
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A highly efficient and simple route for the synthesis of pyrrolo-/indolo[1,2-a]quinolines and naphtho[2,1-b]thiophenes from gem-dibromovinyls and sulphonamides is reported. The noteworthy feature of this report is that the methodology involves a two-step protocol to synthesize tri- and tetracyclic heterocycles in a one-pot fashion through the Cu(I)-catalyzed formation of ynamide followed by a Ag(I)-assisted intramolecular hydroarylation. The photophysical properties of representative examples of pyrrolo- and indolo[1,2-a]quinolines in solid and solution states have also been studied.
- Kiruthika, Selvarangam E.,Nandakumar, Avanashiappan,Perumal, Paramasivan Thirumalai
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supporting information
p. 4424 - 4427
(2015/02/05)
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- Highly selective trifluoroacetic ester/ketone metathesis: An efficient approach to trifluoromethyl ketones and esters
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A highly selective and atom efficient 'trifluoroacetic ester/ketone metathesis' has been sincerely witnessed. Enolizable alkyl (at least two non-hydrogen atoms) aryl ketones were found to react readily with ethyl trifluoroacetate under the promotion of NaH to afford trifluoroacetic ester/ketone exchange products, trifluoromethyl ketones (TFMKs), and aromatic acid esters, which were quite different from the general Claisen condensation products, 1,3-diketones. The outcome of the reaction between ketone and ethyl trifluoroacetate is strongly related to the structures of substrates, the steric congestion caused by alkyl group is in favor of the C-C bond cleavage. DFT investigation further disclosed that the metathesis reaction was a kinetically favored pathway. Using only a slight excess of cheap trifluoromethylation reagent, simple operation and mild conditions make it a practical method for preparation of TFMKs on large scale, as well as a new choice of converting aryl alkyl ketones to aromatic acid esters.
- Zhou, Yuhan,Yang, Dongmei,Luo, Gen,Zhao, Yilong,Luo, Yi,Xue, Na,Qu, Jingping
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p. 4668 - 4674
(2014/06/23)
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- Asymmetric hydroxylative phenol dearomatization promoted by chiral binaphthylic and biphenylic iodanes
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The long-standing quest for chiral hypervalent organoiodine compounds (i.e., iodanes) as metal-free reagents for asymmetric synthesis continues. Although remarkable progress has recently been made in organoiodine-catalyzed reactions using a terminal oxidant in stoichiometric amounts, there is still a significant need for "flaskable" chiral iodane reagents. Herein, we describe the synthesis of new iodobinaphthyls and iodobiphenyls, their successful and selective DMDO-mediated oxidation into either λ3- or λ5-iodanes, and the evaluation of their capacity to promote asymmetric hydroxylative phenol dearomatization (HPD) reactions. Most notably, a C2-symmetrical biphenylic λ5-iodane promoted the HPD-induced conversion of the monoterpene thymol into the corresponding ortho-quinol-based [4+2] cyclodimer (i.e., bis(thymol)) with enantiomeric excesses of up to 94 %.
- Bosset, Cyril,Coffinier, Romain,Peixoto, Philippe A.,El Assal, Mourad,Pouysegu, Laurent,Quideau, Stephane,Miqueu, Karinne,Sotiropoulos, Jean-Marc
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supporting information
p. 9860 - 9864,5
(2014/10/15)
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- Synthesis of 3-Hexyl-4-cyan-6,7-dimethoxy Isocoumarin
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4-(2-Amino-propanamideyl)-3,4,5,6,7,8,9,10-octahydro-5,6, 8-trihydroxy-3-methyl-isocoumarin, which was isolated from Flaveria bidentis (L) Kuntze, had herbicidal activity and its structure was modified in this research in order to get the isocoumarin comp
- Dong, Hai Jiao,Ban, Xu Dong,Li, Cheng,Huo, Jing Qian,Gong, Zhan Hu,Kang, Zhan Hai,Dong, Jin Gao,Zhang, Jin Lin
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p. 3623 - 3625
(2014/08/05)
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- Copper-catalyzed decarboxylative methylation of aromatic carboxylic acids with PhI(OAc)2
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The copper-catalyzed decarboxylative methylation of aromatic carboxylic acids was developed by using PhI(OAc)2 to provide a new strategy for the methylation of aryl acids through the decarboxylation of alkyl acids. The mechanism and the roles of each reactant in the reaction were investigated extensively. Copyright
- Jiang, Yuyu,Pan, Shulei,Zhang, Yanghui,Yu, Jingxun,Liu, Hongqiang
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supporting information
p. 2027 - 2031
(2014/04/17)
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- Palladium-catalyzed annulation reactions of methyl o-halobenzoates with azabicyclic alkenes: A general protocol for the construction of benzo[c]phenanthridine derivatives
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The annulation reaction of methyl o-halobenzoates with azabicyclic alkenes proceeds efficiently to give the corresponding benzo[c]phenanthridine derivatives in good to excellent yields using a developed base-free methodology based on our preliminary studies. Thirty-seven application examples validate the compatibility of the present strategy with different groups, particularly with the electron-deficient ones, that are difficult to access using other traditional methods. In addition, annulation reactions with non-symmetric azabicyclic alkenes are achieved in high regioselectivity.
- Guo, Cui,Huang, Kanglun,Wang, Bo,Xie, Longguang,Xu, Xiaohua
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p. 17271 - 17280
(2013/09/24)
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