- Discovery of Unforeseen Energy-Transfer-Based Transformations Using a Combined Screening Approach
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The discovery of novel (catalytic) transformations and mechanisms is commonly based on rational design. However, many discoveries have resulted directly from experimental serendipity. Building on this, we report a two-dimensional screening protocol, combining “mechanism-based” and “reaction-based” screening and its application to the field of visible light photocatalysis. To this end, two energy-transfer-based cycloaddition reactions could be realized: a notably endergonic energy transfer process allows for the dearomative cycloaddition of benzothiophenes and related heterocycles. Moreover, by sensitization of enone moieties, a [2+2]-cycloaddition to alkynes and an unexpected cycloaddition-rearrangement cascade were discovered. Advanced spectroscopic techniques (in particular transient absorption spectroscopy and pulse radiolysis) were utilized to investigate the underlying photophysical processes and gain insight into reaction kinetics. Combining these results with further mechanistic analysis can eventually turn out to be helpful upon knowledge-driven development of improved systems. Such screening approaches can thus provide complementary access toward novel and more efficient catalytic protocols. Driven by the continuous demand for more efficient and sustainable synthetic reactions, the discovery of novel (catalytic) reactivity patterns remains a major challenge of synthetic chemistry. The discovery of such processes is commonly based on rational design, i.e., the expansion of previously acquired knowledge to new substrate classes or reaction types. However, considering that many groundbreaking discoveries have resulted from experimental serendipity, serendipity-based screening methodologies have been developed as a complementary tool for the discovery of novel transformations. Particularly in the context of visible-light-mediated photocatalysis, which provides a powerful platform from which to develop new radical-based transformations, screening methodologies still have significant potential to discover new reactivity modes. How can catalytic reactions be discovered? Here, a two-dimensional screening strategy for reaction discovery is described. For this purpose, the investigation of single mechanistic steps is merged with combinatorial screening. As a showcase, application to the field of visible light photocatalysis allowed for the discovery of three unexpected cyclization reactions. Extensive mechanistic analysis by advanced spectroscopic and computational tools enabled insights into the underlying molecular processes. In particular, a significantly endergonic sensitization event could be discovered and substantiated by transient absorption spectroscopy.
- Strieth-Kalthoff,Henkel, Christian,Teders, Michael,Kahnt, Axel,Knolle, Wolfgang,Gómez-Suárez, Adrián,Dirian, Konstantin,Alex, Wiebke,Bergander,Daniliuc, Constantin G.,Abel,Guldi, Dirk M.,Glorius
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Read Online
- Multicomponent Coupling Approach to (±)-Frondosin B and a Ring-Expanded Analogue
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(Equation presented) A recently discovered multicomponent coupling reaction is used to give direct access to a late intermediate in the synthesis of frondosin B. This intermediate can also be efficiently converted to a ring-expanded analogue of frondosin
- Kerr, Daniel J.,Willis, Anthony C.,Flynn, Bernard L.
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Read Online
- Synthetic Studies toward Actinorhodin and γ-Actinorhodin by using a Homo-coupling Strategy: Synthesis of Hemiactinorhodin and Hemi-γ-actinorhodin
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A homo-coupling strategy toward the synthesis of actinorhodin and γ-actinorhodin has been explored. The monomeric unit was synthesized by employing an efficient combination of D?tz benzannulation and oxa-Pictet-Spengler reactions. Attempts towards oxidative homo-coupling of the pyranonaphthalene monomer intermediate to give dimer were unsuccessful. Later, monomer pyranonaphthalene was carried forward to complete the synthesis of hemiactinorhodin and hemi-γ-actinorhodin.
- Mulay, Sandip V.,Bhowmik, Amit,Fernandes, Rodney A.
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- Iron- or Palladium-Catalyzed Reaction Cascades Merging Cycloisomerization and Cross-Coupling Chemistry
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A conceptually novel reaction cascade is presented, which allows readily available enynes to be converted into functionalized 1,3-dienes comprising a stereodefined tetrasubstituted alkene unit; such compounds are difficult to make by conventional means. The overall transformation is thought to commence with formation of a metallacyclic intermediate that evolves via cleavage of an unstrained C?X bond in its backbone. This non-canonical cycloisomerization process is followed by a cross-coupling step, such that reductive C?C bond formation regenerates the necessary low-valent metal fragment and hence closes an intricate catalytic cycle. The cascade entails the formation of two new C?C bonds at the expense of the constitutional C?X entity of the substrate: importantly, the extruded group X must not be a heteroelement (X=O, NR), since activated β-C?C bonds can also be broken. This concern was reduced to practice in two largely complementary formats: one procedure relies on the use of alkyl-Grignard reagents in combination with catalytic amounts of Fe(acac)3, whereas the second method amalgamates cycloisomerization with Suzuki coupling by recourse to arylboronic acids and phosphine-ligated palladium catalysts.
- Gomes, Filipe,Echeverria, Pierre-Georges,Fürstner, Alois
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Read Online
- o-Bromo-p-methoxyphenyl ethers. Protecting/radical translocating (PRT) groups that generate radicals from C-H bonds β to oxygen atoms
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The o-bromo-p-methoxyphenyl ether group is introduced as a new protecting/radical translocating (PRT) group. This group protects an alcohol both before and after its use as a translocating group to generate a radical from a C-H bond β to the protected alc
- Curran, Dennis P.,Xu, Jinyou
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Read Online
- A Conformationally Stable Contorted Hexabenzoovalene
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Contorted two-dimensional aromatic molecules are fascinating synthetic targets because they are molecular “cutouts” of nonplanar graphene structures, fullerenes, or carbon nanotubes. In most cases, the curvature is introduced by the implementation of eith
- Baumg?rtner, Kevin,Meza Chincha, Ana Lucia,Dreuw, Andreas,Rominger, Frank,Mastalerz, Michael
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Read Online
- Synthesis of novel tetracycles via an intramolecular Heck reaction with anti-hydride elimination
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(Matrix presented) The catalytic combination of Pd2(dba) 3/HP(t-Bu)3·BF4 and DABCO gives an unusual intramolecular Heck reaction with dihydronaphthalene substrates, yielding formal anti-hydride elimination produ
- Lautens, Mark,Fang, Yuan-Qing
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Read Online
- Coumarins by Direct Annulation: β-Borylacrylates as Ambiphilic C3-Synthons
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Modular β-borylacrylates have been validated as programmable, ambiphilic C3-synthons in the cascade annulation of 2-halo-phenol derivatives to generate structurally and electronically diverse coumarins. Key to this [3+3] disconnection is the BPin unit which serves a dual purpose as both a traceless linker for C(sp2)–C(sp2) coupling, and as a chromophore extension to enable inversion of the alkene geometry via selective energy transfer catalysis. Mild isomerisation is a pre-condition to access 3-substituted coumarins and provides a handle for divergence. The method is showcased in the synthesis of representative natural products that contain this venerable chemotype. Facile entry into π-expanded estrone derivatives modified at the A-ring is disclosed to demonstrate the potential of the method in bioassay development or in drug repurposing.
- Wienhold, Max,Molloy, John J.,Daniliuc, Constantin G.,Gilmour, Ryan
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supporting information
p. 685 - 689
(2020/11/30)
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- Synthetic method 4 - alkoxyphenol compounds
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The invention discloses a synthetic method of 4 - alkoxyphenol compounds, and belongs to the field of organic chemical synthesis. The method is as follows: An aryl alkyl ether compound is added to the sealing tube. The catalyst dimerization acetic acid rhodium and the oxidizing agent iodobenzene diethyl ester are added, a solvent trifluoroacetic anhydride is added, and the 4 -alkoxyphenol compound is prepared by heating reaction. To the invention, high regioselectivity direct hydroxylation of the aryl alkyl ether compound is realized, the application range of the substrate is wide, the yield is high, the activity after amplification reaction does not significantly decay, and higher yield is still obtained. The utility model has good practicability and industrial application prospect.
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Paragraph 0094-0096
(2021/09/29)
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- Para -Selective hydroxylation of alkyl aryl ethers
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para-Selective hydroxylation of alkyl aryl ethers is established, which proceeds with a ruthenium(ii) catalyst, hypervalent iodine(iii) and trifluoroacetic anhydride via a radical mechanism. This protocol tolerates a wide scope of substrates and provides a facile and efficient method for preparing clinical drugs monobenzone and pramocaine on a gram scale.
- Zhu, Runqing,Sun, Qianqian,Li, Jing,Li, Luohao,Gao, Qinghe,Wang, Yakun,Fang, Lizhen
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supporting information
p. 13190 - 13193
(2021/12/16)
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- Regioselective monobromination of phenols with KBr and ZnAl–BrO3?–layered double hydroxides
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The regioselective mono-bromination of phenols has been successfully developed with KBr and ZnAl–BrO3?–layered double hydroxides (abbreviated as ZnAl–BrO3?–LDHs) as brominating reagents. The para site is much favorable and the ortho site takes the priority if para site is occupied. This reaction featured with excellent regioselectivity, cheap brominating reagents, mild reaction condition, high atom economy, broad substrate scope, and provided an efficient method to synthesize bromophenols.
- Wang, Ligeng,Feng, Chun,Zhang, Yan,Hu, Jun
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supporting information
(2020/02/22)
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- Mild and Regioselective Bromination of Phenols with TMSBr
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In this work, an unexpected promoting effect of by-product thioether was observed, leading to a mild and regioselective bromination of phenols with TMSBr. This method can tolerate a series of functional groups such as the reactive methoxyl, amide, fluoro, chloro, bromo, aldehyde, ketone and ester groups, and has the potential to recycle the by-product thioether and isolate the desired product under column chromatography-free conditions. Mechanism studies revealed that O–H···S hydrogen bond may be formed between phenol and by-product thioether. Possibly owing to the steric hindrance effect from by-product thioether, the electrophilic bromination at para-position of phenols is much favorable.
- Ma, Xiantao,Yu, Jing,Jiang, Mengyuan,Wang, Mengyu,Tang, Lin,Wei, Mengmeng,Zhou, Qiuju
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supporting information
p. 4593 - 4596
(2019/07/05)
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- A phenol compound high regioselective bromination method
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The invention discloses a phenol compound high regioselective bromination of the method, the method to trimethyl silane as brominating agent, in order to aryl sulfoxide as activator, with the phenol compound in the 0 - 50 °C lower, in a solvent, the reaction is stirred under an atmosphere of nitrogen at 1 - 12 hours, to realize the phenol compound high regioselective bromination, filtered, extraction columns chromatography separation to obtain the bromo phenol compound. This invention adopts the aryl sulfoxide as activator, sulfoxide substituted Kiev, on the one hand so that the phenol compound bromo the higher selectivity of the reaction region, and when the phenol compound hydroxy alignment not substituted basetime, regional selective para - bromo product, when the phenol compound hydroxy position there is substituted basetime, selective ortho - bromo product obtained; on the other hand if it through the filter, the extraction can be realized at the same time the isolation and purification of the recycling of the by-product, compared with column chromatography, reduces the separation and purification cost.
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Paragraph 0037; 0038; 0039
(2019/06/05)
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- Trifluoromethyl aryl sulfonates (TFMS): An applicable trifluoromethoxylation reagent
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Fluorine is probably another favorite hetero-atom for incorporation into small molecules after nitrogen. Among many fluorine-containing groups, trifluoromethyl aryl ethers (ArOCF3) have unique properties in drug design and are difficult to be synthesized, and many different methods were developed to prepare them. A novel one-pot synthesis of o-iodine-aryl trifluoromethyl ethers (ArOCF3I) was described by the reaction of trifluoromethoxylation and iodination with trifluoromethyl aryl sulfonates (TFMS) in this manuscript. The reaction conditions were optimized by screening different solvents, crown ethers, substrates and the ratios and the yields of products were in moderate to high yields (up to 86%).
- Lei, Meng,Miao, Hang,Wang, Xueyuan,Zhang, Wen,Zhu, Chengjian,Lu, Xiaqiang,Shen, Jian,Qin, Yanru,Zhang, Haoyang,Sha, Sijia,Zhu, Yongqiang
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supporting information
p. 1389 - 1392
(2019/04/30)
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- FUSED TRICYCLIC COMPOUNDS AS RAF KINASE INHIBITORS
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Provided are certain fused tricyclic compounds and salts thereof, compositions thereof, and methods of use therefor.
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Paragraph 0209; 0339; 0340-0341
(2021/02/16)
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- An efficient synthesis of 1-hydroxy-5,8-dimethoxy-2-naphthaldehyde
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An efficient method for the preparation of 1-hydroxy-5, 8-dimethoxy-2-naphthaldehyde (1) was developed with a high overall yield (73.8%). Compared with the previously reported method, the reaction conditions are milder and the work-up of each step is much simpler. Moreover, the starting material considerably reduces the cost and is suitable for large-scale preparations.
- Zhang, Qijing,Dong, Jinyun,Huang, Guang,Li, Shaoshun
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p. 334 - 338
(2018/02/22)
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- o-xylylene bis(triethyl ammonium tribromide) as a mild and recyclable reagent for rapid and regioselective bromination of anilines and phenols
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Background: o-Xylylene bis(triethyl ammonium tribromide) (OXBTEATB) as a recyclable and high bromine containing di-(tribromide) reagent has been employed for the bromination of various organic substrates such as phenol and aniline or its derivatives. This catalyst can be recovered and reused several times. Methods: Aryl bromides shown in Table 1, were easily produced from bromination of aromatic compounds by OXBTEATB. This high-yield process lets the reagents to be recycled and reused. Results: As shown in Table 1, substituted anilines, phenols and β-naphthol were found to be the most reactive and immediately converted to the corresponding mono-brominated products by OXBTEATB. Conclusion: OXBTEATB can be considered a solidified bromine. This novel reagent has variable solubility in different polar protic and aprotic solvents but insoluble in non-polar aprotic solvent. Subsequently, OXBTEATB can be recognized as a more useful brominating and regioselective catalyst than the liquid bromine.
- Hemati, Roya,Shahvelayati, Ashraf S.,Yadollahzadeh, Khadijeh
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p. 682 - 687
(2018/07/14)
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- Photoinduced Synthesis of Dibenzofurans: Intramolecular and Intermolecular Comparative Methodologies
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The SRN1 reaction has been used as a powerful tool for the synthesis of heterocycles, and only a few studies about photoinduced intramolecular cyclization to generate a new C-O bond by a radical pathway have been reported. This work introduces two strategies for the synthesis of substituted dibenzofurans by electron transfer (eT) reactions. The first one is a three-step process that comprises bromination of o-arylphenols, Suzuki-Miyaura cross-coupling and photoinduced cyclization in order to obtain the above-mentioned products. The second one is a metal-free procedure and does not require any photocatalyst. Different solvents were tested, and the yields ranged from low to moderate. A comparison was established between both methodologies, showing that the second one is the most suitable for the synthesis of dibenzofurans.
- Camargo Solórzano, Patricia,Brigante, Federico,Pierini, Adriana B.,Jimenez, Liliana B.
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supporting information
p. 7867 - 7877
(2018/06/11)
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- HEMOGLOBIN MODIFIER COMPOUNDS AND USES THEREOF
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Described herein are compounds, including pharmaceutically acceptable salts thereof, methods of making such compounds, pharmaceutical compositions comprising such compounds, and methods of using such compounds to treat, prevent or diagnose blood-based diseases, disorders or conditions.
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Paragraph 00381
(2018/02/28)
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- CONDENSED TRICYCLIC COMPOUNDS AS Raf KINASE INHIBITORS
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PROBLEM TO BE SOLVED: To provide specific tricyclic compounds that can be useful for inhibiting Raf kinase and for treating disorders mediated by Raf kinase. SOLUTION: A compound is represented by the general formula 1 in the figure. (Q is C or N; W is C or N; X is CH2 or O; Y is NR12, O or S; Z is O, S, NR13, CO, SO, SO2 or CR13R14; R1 to R6 are each independently hydrogen, halogen, haloalkyl, alkyl or the like.) SELECTED DRAWING: None COPYRIGHT: (C)2017,JPO&INPIT
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Paragraph 0212; 0213
(2017/01/05)
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- 5. 5 'bit connected 1, 1' - biphenyl axle chiral 2, 2' - diphosphine ligands and method for preparing same
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The invention relates to a 5,5'-connected 1,1'-biphenyl axially chiral 2,2'-diphosphine ligand and a preparation method thereof, and belongs to the technical field of chemical industry. The 5,5'-connected 1,1'-biphenyl axially chiral 2,2'-diphosphine liga
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Paragraph 0038; 0039
(2018/11/03)
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- Accelerated Discovery in Photocatalysis using a Mechanism-Based Screening Method
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Herein, we report a conceptually novel mechanism-based screening approach to accelerate discovery in photocatalysis. In contrast to most screening methods, which consider reactions as discrete entities, this approach instead focuses on a single constituent mechanistic step of a catalytic reaction. Using luminescence spectroscopy to investigate the key quenching step in photocatalytic reactions, an initial screen of 100 compounds led to the discovery of two promising substrate classes. Moreover, a second, more focused screen provided mechanistic insights useful in developing proof-of-concept reactions. Overall, this fast and straightforward approach both facilitated the discovery and aided the development of new light-promoted reactions and suggests that mechanism-based screening strategies could become useful tools in the hunt for new reactivity. Enlightened! A mechanism-based screening approach can accelerate discovery in photocatalysis. It focuses on a single mechanistic step of a reaction class: the quenching step central to photocatalytic transformations. Luminescence spectroscopy was used to screen 100 compounds, identifying two promising substrate classes. A second, more-focused screen provided mechanistic insights for developing proof-of-concept reactions.
- Hopkinson, Matthew N.,Gómez-Suárez, Adrián,Teders, Michael,Sahoo, Basudev,Glorius, Frank
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supporting information
p. 4361 - 4366
(2016/04/05)
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- Condensed tricyclic compounds as RAF kinase inhibitors
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The invention provides certain condensed tricyclic compounds as well as salt, compositions and application methods thereof.
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Paragraph 0358; 0565; 0566; 0567; 0568; 0569
(2016/10/07)
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- Hexamethonium bis(tribromide) (HMBTB) a recyclable and high bromine containing reagent
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A recyclable and high bromine containing di-(tribromide) reagent, hexamethonium bis(tribromide) (HMBTB) has been synthesized and utilized for the bromination of various organic substrates. The spent reagent hexamethonium bromide (HMB) can be effectively recycled by regenerating and reusing it without significant loss of activity. The crystalline and stable bis(tribromide) is an effective storehouse of very high percentage of active bromine requiring just half an equivalent of it for complete bromination. Both the Br3- moieties in HMBTB are nearly linear with Br-Br-Br angle of 179.55°.
- Paul, Bappi,Bhuyan, Bishal,Purkayastha, Debraj D.,Dhar, Siddhartha S.,Patel, Bhisma K.
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p. 5646 - 5650
(2015/09/21)
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- A concise approach to tetracyclic spiroamine scaffold of erythrinan alkaloids via an oxidative dearomatization-spirocyclization sequence
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This paper describes a novel synthetic approach to 11,12-dimethoxy-8,9-dihydro-1H-indolo[7a,1-a]isoquinoline-2,6-dione, which is a key synthetic intermediate to some erythrinan alkaloids. This concise approach features an oxidative dearomatization-spirocy
- Saito, Emi,Akihiko, Nakamura,Masahisa, Nakada
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p. 1387 - 1395
(2015/05/26)
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- Efficient and Practical Oxidative Bromination and Iodination of Arenes and Heteroarenes with DMSO and Hydrogen Halide: A Mild Protocol for Late-Stage Functionalization
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An efficient and practical system for inexpensive bromination and iodination of arenes as well as heteroarenes by using readily available dimethyl sulfoxide (DMSO) and HX (X = Br, I) reagents is reported. This mild oxidative system demonstrates a versatile protocol for the synthesis of aryl halides. HX (X = Br, I) are employed as halogenating reagents when combined with DMSO which participates in the present chemistry as a mild and inexpensive oxidant. This oxidative system is amenable to late-stage bromination of natural products. The kilogram-scale experiment (>95% yield) shows great potential for industrial application.
- Song, Song,Sun, Xiang,Li, Xinwei,Yuan, Yizhi,Jiao, Ning
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supporting information
p. 2886 - 2889
(2015/06/30)
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- FUSED TRICYCLIC COMPOUNDS AS RAF KINASE INHIBITORS
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Provided are certain fused tricyclic compounds and salts thereof, compositions thereof, and methods of use therefor.
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Paragraph 0378-0380
(2015/02/25)
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- FUSED TRICYCLIC AMIDE COMPOUNDS AS MULTIPLE KINASE INHIBITORS
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Provided are fused tricyclic amide compounds, pharmaceutical compositions comprising at least one such fused tricyclic compound, processes for the preparation thereof, and the use thereof in therapy. Disclosed herein are certain tricyclic amide compounds that can be useful for inhibiting multiple (specifically BRAF and/or EGFR-T790M) kinases and for treating disorders mediated thereby.
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Page/Page column 107
(2015/01/16)
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- A new recyclable 1,4-bis(3-methylimidazolium-1-yl)butane ditribromide [bMImB]·(Br3)2 ionic liquid reagent for selective bromination of anilines or phenols and α-bromination of alkanones under mild conditions
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1,4-Bis(3-methylimidazolium-1-yl)butane ditribromide [bMImB] ·(Br3)2 has been synthesized and explored as a new efficient brominating agent. The crystalline ditribromide reagent is stable for months and acts as a safe source of bromine requiring just 0.5 equiv. for complete bromination. It has a high active bromine content per molecule and shows a remarkable reactivity toward various substrates in acetonitrile at room temperature. The prepared reagents were used as a green recyclable reaction media for the selective bromination of anilines, phenols and α-bromination of alkanones in excellent yields. The product can easily be isolated by just washing the highly water soluble 1,4-bis(3-methylimidazolium-1-yl)butane ditribromide [bMImB]·(Br3)2 from the brominated product. The spent reagent can be recovered, regenerated, and reused without any significant loss. the Partner Organisations 2014.
- Veisi, Hojat,Sedrpoushan, Alireza,Mohammadi, Pourya,Faraji, Ali Reza,Sajjadifar, Sami
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p. 25898 - 25903
(2014/07/07)
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- Visible-light photoredox catalysis enabled bromination of phenols and alkenes
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A mild and efficient methodology for the bromination of phenols and alkenes has been developed utilizing visible light-induced photoredox catalysis. The bromine was generated in situ from the oxidation of Br- by Ru(bpy)33+, both of which resulted from the oxidative quenching process.
- Zhao, Yating,Li, Zhe,Yang, Chao,Lin, Run,Xia, Wujiong
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p. 622 - 627
(2014/04/17)
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- Synthesis of o-chlorophenols via an unexpected nucleophilic chlorination of quinone monoketals mediated by N,N′-dimethylhydrazine dihydrochloride
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An unexpected nucleophilic chlorination of a quinone monoketal while carrying out a pyrazolidine synthesis has led to a general preparation of multisubstituted phenols. The products are obtained in good to high yields under mild conditions. The bridged pyrazolidines that were the original targets are obtained in the presence of a protic solvent. This journal is the Partner Organisations 2014.
- Yin, Zhiwei,Zhang, Jinzhu,Wu, Jing,Green, Riana,Li, Sihan,Zheng, Shengping
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p. 2854 - 2858
(2014/05/06)
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- FUSED TRICYCLIC COMPOUNDS AS RAF KINASE INHIBITORS
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Provided are certain fused tricyclic compounds and salts thereof, compositions thereof, and methods of use therefor.
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Page/Page column 72
(2013/07/19)
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- Synthesis of tetrasubstituted alkenes through a palladium-catalyzed domino carbopalladation/C-H-activation reaction
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Helical tetrasubstituted alkenes (7) were obtained in a highly efficient way through a palladium-catalyzed domino-carbopalladation/CH-activation reaction of propargylic alcohols 6 in good to excellent yields. Electron-withdrawing- and electron-donating substituents can be introduced onto the upper and lower aromatic rings. The substrates (6) for the domino process were synthesized by addition of the lithiated alkyne (20) to various aldehydes (19); moreover, the substrates were accessible enantioselectively (in 95 % ee) by reduction of the corresponding ketone using the Noyori procedure. Copyright
- Tietze, Lutz F.,Hungerland, Tim,Duefert, Alexander,Objartel, Ina,Stalke, Dietmar
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supporting information; experimental part
p. 3286 - 3291
(2012/04/17)
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- Gold-catalyzed isomerization of unactivated allenes into 1,3-dienes under ambient conditions
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We have developed a gold-catalyzed isomerization of unactivated allenes into 1,3-dienes with nitrosobenzene as an additive. This reaction proceeded almost exclusively at room temperature for highly substituted allenes. The utility of this reaction is manifested by the development of one-pot [4+2]-cycloaddition of allenes and reactive alkenes.
- Ting, Chun-Ming,Hsu, Yi-Ling,Liu, Rai-Shung
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supporting information; experimental part
p. 6577 - 6579
(2012/07/31)
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- Copper-catalyzed cross-coupling interrupted by an opportunistic smiles rearrangement: An efficient domino approach to dibenzoxazepinones
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Unexpected Smiles! An unusual and highly regioselective synthesis of dibenzoxazepinones by a domino sequence assisted by an unexpected Smiles rearrangement is reported. The process is effective on electronically differentiated phenols and shows a high tolerance to variation in the benzamide substituents. A plausible path for the reaction, supported by preliminary mechanistic data, is offered. Copyright
- Kitching, Matthew O.,Hurst, Timothy E.,Snieckus, Victor
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supporting information; experimental part
p. 2925 - 2929
(2012/05/04)
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- Synthesis and fluorescence characterization of MEHPPV oligomers
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Trimer, tetramer, and pentamer oligomers based on the polymer backbone structure of poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene] (MEHPPV) have been synthesized by Horner-Wadsworth-Emmons reactions. The fluorescence spectra, emission quantum
- Tilley, Andrew J.,Danczak, Stephen M.,Browne, Christine,Young, Timothy,Tan, Tina,Ghiggino, Kenneth P.,Smith, Trevor A.,White, Jonathan
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experimental part
p. 3372 - 3380
(2011/07/07)
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- Simple and improved regioselective brominations of aromatic compounds using N-benzyl-N,N-dimethylanilinium peroxodisulfate in the presence of potassium bromide under mild reactions conditions
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A simple, efficient, and mild method for the selective bromination of some activated aromatic compounds using N-benzyl-N,N-dimethylanilinium peroxodisulfate in the presence of potassium bromide in non-aqueous solution is reported. The results obtained revealed good to excellent selectivity between the ortho and para positions of phenols and methoxyarenes.
- Ghasemnejad-Bosra, Hassan,Ramzanian-Lehmali, Farhad,Jafari, Somaye
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experimental part
p. 685 - 692
(2012/01/16)
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- Synthesis and reactivity studies of a new reagent, ethyltriphenylphosphonium tribromide
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A new reagent, ethyltriphenyl phosphonium tribromide (ETPPTB), has been synthesized and studied. Results show that the reagent is quite efficient for various reactions such as organic bominations, acylations, and isothiocyanate preparation. Copyright
- Jamir, Latonglila,Alimenla,Kumar, Anil,Sinha, Dipak,Sinha, Upasana B.
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experimental part
p. 147 - 155
(2011/03/17)
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- From tropos to atropos: 5,5′-bridged 2,2′-bis(diphenylphosphino)biphenyls as chiral ligands for highly enantioselective palladium-catalyzed hydrogenation of α-phthalimide ketones
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A class of atropisomeric diphosphine ligands with a wide range of dihedral angles has been developed. X-ray study of the Pd(II) complexes of these ligands showed that as the bridge length increased, the dihedral angles and the ligand bite angles increased
- Wang, Changqing,Yang, Guoqiang,Zhuang, Jing,Zhang, Wanbin
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scheme or table
p. 2044 - 2047
(2010/06/19)
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- Mild, efficient, and regioselective monobromination of arylamines and phenols using [BBIm]Br3 as a new reagent
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We report here an efficient method for the synthesis and characterization of the room-temperature ionic liquid 1,3-di-n-butylimidazolium tribromide ([BBIm]Br3) (2) and its application as an efficient reagent and solvent for regioselective bromination of arylamines and phenols under mild conditions. The bromination was carried out in the absence of organic solvents, and in most cases, the only extraction solvent needed was water. The spent 1,3-di-n-butylimidazolium bromide (1) was easily recycled.
- Borikar, Sanjay P.,Daniel, Thomas,Paul, Vincent
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experimental part
p. 647 - 653
(2011/02/27)
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- INHIBITORS OF ACETYL-COA CARBOXYLASE
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The present invention relates to compounds that act as acetyl-CoA carboxylase (ACC) inhibitors. The invention also relates to methods of preparing the compounds, compositions containing the compounds, and to methods of treatment using the compounds.
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Page/Page column 60
(2010/11/17)
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- An efficient, rapid, and regioselective bromination of anilines and phenols with 1-butyl-3-methylpyridinium tribromide as a new reagent/solvent under mild conditions
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1-Butyl-3-methylpyridinium tribromide, [BMPy]Br3 proves to be a highly efficient, regioselective reagent/solvent for nuclear bromination of various anilines and phenols. The synthesis and characterization of the room temperature ionic liquid [BMPy]Br3 (2) is described. The bromination was carried out in the absence of organic solvents and in most cases the only extraction solvent needed was water. The spent 1-butyl-3-methylpyridinium bromide (1) was easily recycled.
- Borikar, Sanjay P.,Daniel, Thomas,Paul, Vincent
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scheme or table
p. 1007 - 1009
(2009/05/11)
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- Synthesis of tricyclic and tetracyclic sultones by Pd-catalyzed intramolecular cyclization
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A new efficient synthesis of aromatic six-membered ring sultones by the implementation of ligand-free Pd-catalyzed intramolecular cyclization of aromatic sulfonates derived from various bromo phenols and naphthols is described.
- Majumdar,Mondal, Shovan,Ghosh, Debankan
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scheme or table
p. 4781 - 4784
(2011/03/18)
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- Synthesis of a C8 oxygenated pyranonaphthoquinone: a useful precursor to dimeric pyranonaphthoquinones
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The synthesis of a pyranonaphthoquinone bearing an oxygenated substituent at C8 is reported. The oxygen substituent at C8 provides a key functionality for use as a homocoupling precursor for the synthesis of a dimeric pyranonaphthoquinone.
- Bachu, Prabhakar,Sperry, Jonathan,Brimble, Margaret A.
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p. 3343 - 3350
(2008/09/19)
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- Bromination of some aromatic compounds with potassium bromide in the presence of benzyltriphenylphosphonium peroxodisulfate
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A simple, efficient, and mild method for selective bromination of some activated aromatic compounds using potassium bromide in the presence of benzyltriphenylphosphonium peroxodisulfate in nonaqueous solution is reported. The results obtained revealed good to excellent selectivity between ortho and para positions of phenols and methoxyarenes. Copyright Taylor & Francis Group, LLC.
- Tajik, Hassan,Mohammadpoor-Baltork, Iraj,Albadi, Jalal
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p. 323 - 328
(2007/10/03)
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- Phenoxy thiazole derivatives as potent and selective acetyl-CoA carboxylase 2 inhibitors: Modulation of isozyme selectivity by incorporation of phenyl ring substituents
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A phenyl ring substitution strategy was employed to optimize the ACC2 potency and selectivity profiles of a recently discovered phenoxy thiazolyl series of acetyl-CoA carboxylase inhibitors. Ring substituents were shown to dramatically affect isozyme sele
- Clark, Richard F.,Zhang, Tianyuan,Wang, Xiaojun,Wang, Rongqi,Zhang, Xiaolin,Camp, Heidi S.,Beutel, Bruce A.,Sham, Hing L.,Gu, Yu Gui
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p. 1961 - 1965
(2008/02/02)
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- Copper(II) bromide: A simple and selective monobromination reagent for electron-rich aromatic compounds
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Copper(II) bromide was found to be a simple and efficient reagent for monobromination of electron-rich aromatic compounds at room temperature. The reaction proceeded smoothly with phenols, aryl alkyl ethers, and aromatic amines to afford the corresponding monobrominated product selectively in moderate to good yields. Copyright Taylor & Francis Group, LLC.
- Bhatt, Suchitra,Nayak, Sandip K.
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p. 1381 - 1388
(2008/02/01)
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- 1-Aminomethylbenzocycloalkanes: Conformationally restricted hallucinogenic phenethylamine analogues as functionally selective 5-HT2A receptor agonists
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A series of conformationally restricted analogues of the hallucinogenic phenethylamine 1 (2,5-dimethoxy-4-bromophenethylamine, 2C-B) was synthesized to test several hypotheses concerning the bioactive conformation of phenethylamine ligands upon binding to the 5-HT2A receptor. These benzocycloalkane analogues were assayed for their receptor binding affinity and ability to activate downstream signaling pathways, and one exceptional compound was selected for testing in an in vivo drug discrimination model of hallucinogenesis. All compounds were examined in silico by virtual docking into a homology model of the 5-HT2A receptor. On the basis of these docking experiments, it was predicted that the R enantiomer of benzocyclobutene analogue 2 would be the most potent. Subsequent chemical resolution and X-ray crystallography confirmed this prediction, as (R)-2 proved to be equipotent to LSD in rats trained to discriminate LSD from saline. Thus, we propose that the conformation of 2 mimics the active binding conformation of the more flexible phenethylamine type hallucinogens. In addition, (R)-2 is one of the most potent and selective compounds yet discovered in the in vivo drug discrimination assay. Further, 2 was found to be a functionally selective agonist at the 5-HT 2A receptor, having 65-fold greater potency in stimulating phosphoinositide turnover than in producing arachidonic acid release. If hallucinogenic effects are correlated with arachidonic acid production, such functionally selective 5-HT2A receptor agonists may lack the intoxicating properties of hallucinogens such as LSD.
- McLean, Thomas H.,Parrish, Jason C.,Braden, Michael R.,Marona-Lewicka, Danuta,Gallardo-Godoy, Alejandra,Nichols, David E.
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p. 5794 - 5803
(2007/10/03)
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- Aminoalkylbenzofurans as serotonin (5-HT(2c)) agonists
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The present invention provides serotonergic aminoalkylbenzofurans of Formula (I): where R, R1, R2, R3, R4, R4′, R5, R5′, and R12 are as described in the specification.
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Page/Page column 21
(2010/11/08)
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- A new recyclable ditribromide reagent for efficient bromination under solvent free condition
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1,2-Dipyridiniumditribromide-ethane (DPTBE) has been synthesized and explored as a new efficient brominating agent. The crystalline ditribromide reagent is stable for months and acts as a safe source of bromine requiring just 0.5 equiv for complete bromination. It has high active bromine content per molecule and shows a remarkable reactivity compared to other tribromide reagents toward various substrates by just grinding the reagent and substrates in a porcelain mortar at room temperature. No organic solvent has been used during any stage of the reaction for substrates giving product as solid. Product can easily be isolated by just washing the highly water soluble 1,2- dipyridiniumdibromide-ethane (DPDBE) from the brominated product. The spent reagent can be recovered, regenerated, and reused without any significant loss.
- Kavala, Veerababurao,Naik, Sarala,Patel, Bhisma K.
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p. 4267 - 4271
(2007/10/03)
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- Palladium-catalyzed couplings to nucleophilic heteroarenes: The total synthesis of (-)-frondosin B
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The total synthesis of (-)-frondosin B, the enantiomer of naturally-occuring (+)-frondosin B, is described, wherein a palladium-catalyzed cyclization is used to establish the tetracyclic ring system of the natural product. Graphical Abstract.
- Hughes, Chambers C.,Trauner, Dirk
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p. 9675 - 9686
(2007/10/03)
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- Synthesis and pharmacological characterization of a series of geometrically constrained 5-HT2A/2C receptor ligands
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In studies of the SAR of phenethylamine-type serotonin 5-HT2A receptor agonists, substituted conformationally constrained tetrahydronaphthofurans were designed to investigate the optimal conformation of the 2-aminoethyl moiety. These compounds
- Chambers, James J.,Parrish, Jason C.,Jensen, Niels H.,Kurrasch-Orbaugh, Deborah M.,Marona-Lewicka, Danuta,Nichols, David E.
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p. 3526 - 3535
(2007/10/03)
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