- Derivatizing Tribenzothiophene-Fused Hexa-peri-hexabenzocoronenes with Tunable Optoelectronic Properties
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A series of trisbenzothieno[1,2:7,8:13,14]hexa-peri-hexabenzocoronenes were synthesized and characterized by a combination of NMR, 2D NMR, MALDI-TOF MS, UV/Vis absorption spectroscopy, and 2D-WAXS measurement. By structural modulation like decoration of e
- Liu, Yi,Marszalek, Tomasz,Müllen, Klaus,Pisula, Wojciech,Feng, Xinliang
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- Catalyst- and acid-free Markovnikov hydration of alkynes in a sustainable H2O/ethyl lactate system
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An efficient and sustainable protocol for the hydration of alkynes has been developed under metal/acid/catalyst/ligand-free conditions in a water/ethyl lactate mixture. The hydrogen-bond network in the ethyl lactate and water mixture plays a crucial and decisive role in activating the alkynes for hydration to afford the corresponding methyl ketones. This strategy gives the Markovnikov (ketone) addition product selectively over other possible products. The essential role of hydrogen bonding has been confirmed by experimental and theoretical techniques. A probable mechanism has been suggested by various control tests. The efficacy of the method has been further explored for the competent production of value-added α,β-unsaturated carbonyl compounds through the reaction of aldehydes with alkynes as ketonic surrogates. The environmentally benign hydration method takes place under mild conditions, has broad functional-group compatibility, and uses the ethyl lactate/water (1:3) medium as a “green alternative” in the absence of any hazardous, harmful, or expensive substances.
- Dandia, Anshu,Saini, Pratibha,Chithra,Vennapusa, Sivaranjana Reddy,Parewa, Vijay
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- The intramolecular reaction of acetophenoneN-tosylhydrazone and vinyl: Br?nsted acid-promoted cationic cyclization toward polysubstituted indenes
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In the presence of TsNHNH2, a Br?nsted acid-promoted intramolecular cyclization ofo-(1-arylvinyl) acetophenone derivatives was developed, leading to polysubstituted indenes with complexity and diversity in moderate to excellent yields. In sharp contrast with either the radical or carbene involved cyclization of aldehydicN-tosylhydrazone with vinyl, a cationic cyclization pathway was involved, whereN-tosylhydrazone served as an electrophile and alkylation reagent during this transformation.
- Wang, Zhixin,Li, Yang,Chen, Fan,Qian, Peng-Cheng,Cheng, Jiang
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p. 1810 - 1813
(2021/02/27)
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- α-Oxocarboxylic Acids as Three-Carbon Insertion Units for Palladium-Catalyzed Decarboxylative Cascade Synthesis of Diverse Fused Heteropolycycles
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A novel palladium-catalyzed decarboxylative cascade cyclization for the assembly of diverse fused heteropolycycles by employing α-oxocarboxylic acids as three-carbon insertion units is reported. This protocol enables the synthesis of isoquinolinedione- and indolo[2,1-a]isoquinolinone-fused benzocycloheptanones in moderate to good yields by the use of different aryl iodides, including alkene-tethered 2-iodobenzamides and 2-(2-iodophenyl)-1H-indoles. Notably, the approach achieves simultaneous construction of both six- and seven-membered rings via sequential intramolecular carbopalladation, C-H activation, and decarboxylation.
- Zhou, Liwei,Qiao, Shujia,Zhou, Fengru,Xuchen, Xinyu,Deng, Guobo,Yang, Yuan,Liang, Yun
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p. 2878 - 2883
(2021/05/05)
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- Divergent Access to Benzocycles through Copper-Catalyzed Borylative Cyclizations
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A copper-catalyzed chemodivergent approach to five- and six-membered benzocycles from dienyl arenes tethered with a ketone has been developed. Through proper choice of coordinating ligands and catalytic conditions, copper-catalyzed borylative cyclization of a single dienyl arene can be diverted to two different pathways, leading to indanols and dihydronaphthalenols with high stereoselectivity. The chiral bidentate bisphosphine ligand (S,S)-Ph-BPE was optimal for asymmetric copper-allyl addition to a tethered ketone via a boat-like transition state, whereas NHC ligands led to boro-allyl addition producing indanols with high diastereoselectivity. (Figure presented.).
- Yoon, Wan Seok,Han, Jung Tae,Yun, Jaesook
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p. 4953 - 4959
(2021/09/14)
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- Atmosphere-Controlled Palladium-Catalyzed Divergent Decarboxylative Cyclization of 2-Iodobiphenyls and α-Oxocarboxylic Acids
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A novel palladium-catalyzed divergent decarboxylative cyclization of 2-iodobiphenyls and α-oxocarboxylic acids utilizing the atmosphere as a controlled switch is reported. Under the protection of a nitrogen atmosphere, tribenzotropones are synthesized by a [4 + 3] decarboxylative cyclization. Employing a palladium/O2 system enables a [4 + 2] decarboxylative cyclization to assemble triphenylenes. Notably, preliminary mechanistic studies indicate that the formation of triphenylenes involves a double decarboxylation.
- Zhou, Liwei,Sun, Mingjie,Zhou, Fengru,Deng, Guobo,Yang, Yuan,Liang, Yun
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p. 7150 - 7155
(2021/09/18)
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- Asymmetric Synthesis and Application of Chiral Spirosilabiindanes
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Reported here is the development of a class of chiral spirosilabiindane scaffolds by Rh-catalyzed asymmetric double hydrosilation, for the first time. Enantiopure SPSiOL (spirosilabiindane diol), a new type of chiral building block for the preparation of various chiral ligands and catalysts, was readily prepared on greater than 10 gram scale using this protocol. The potential of this new spirosilabiindane scaffold in asymmetric catalysis was preliminarily demonstrated by development of the corresponding monodentate phosphoramidite ligands (SPSiPhos), which were used in both a Rh-catalyzed hydrogenation and a Pd-catalyzed intramolecular carboamination.
- Chang, Xin,Chen, Hong-Chao,Li, Chuan-Ying,Ma, Pei-Long,Wang, Peng
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p. 8937 - 8940
(2020/04/30)
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- Synthesis of fluorenyl alcohols: Via cooperative palladium/norbornene catalysis
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Herein, we report a novel catalytic synthesis of substituted 9H-fluoren-9-ols starting from aryl iodides and secondary ortho-bromobenzyl alcohols in the presence of palladium/norbornene as a catalytic system. The present protocol exhibits high functional
- Casnati, Alessandra,Fontana, Marco,Motti, Elena,Della Ca, Nicola
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p. 6165 - 6173
(2019/07/04)
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- PdII-Catalyzed Oxidative Tandem aza-Wacker/Heck Cyclization for the Construction of Fused 5,6-Bicyclic N,O-Heterocycles
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A PdII-catalyzed oxidative tandem cyclization was developed for the construction of fused 5,6-bicyclic N, O-heterocycles. This reaction was enabled by the combined use of a 3-methylpyridine ligand and pentafluorobenzoic acid additive. A range of heterocyclic products with different substituents could be prepared in moderate to good yields via this methodology. Several transformations, including a scaled-up preparation of product 2 a, were also carried out showing the good applicability of our methodology.
- Ye, Chenghao,Kou, Xuezhen,Xia, Jingzhao,Yang, Guoqiang,Kong, Li,Wei, Quhao,Zhang, Wanbin
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p. 1897 - 1901
(2018/07/31)
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- Base-promoted nucleophilic fluoroarenes substitution of C–F bonds
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With the use of KOH/DMSO as the superbase medium, the nucleophilic fluoroarene substitution for C–F bonds is presented. The transformation proceeds smoothly with the use of fluoroarenes bearing not only electron-withdrawing group, but also electron-donating group and a variety of nucleophiles such as alcohols, phenols, amines, amides and nitrogen-heterocyclic compounds. The double nucleophilic substitution using ortho-difluoroarenes and nucleophiles bearing ortho-dinucleophilic groups results in the formation of 2,3-dihydro-1,4-benzodioxins, dibenzo[b,e][1,4]dioxins and 10H-phenoxazines in moderate to good yields.
- Su, Ji,Chen, Qian,Lu, Le,Ma, Yuan,Auyoung, George Hong Lok,Hua, Ruimao
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supporting information
p. 303 - 307
(2017/12/11)
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- Air-stable μ2-hydroxyl bridged cationic binuclear complexes of zirconocene perfluorooctanesulfonates: their structures, characterization and application
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Three air-stable zirconocene perfluoro-octanesulfonates were successfully synthesized by treatment of C8F17SO3Ag with (RCp)2ZrCl2 [R = H, n-Bu, t-Bu]. According to X-ray analysis, they have μ2-hydroxyl bridged cationic binuclear structures: (i) [CpZr(OH2)3]2(μ2-OH)2(OSO2C8F17)4·2THF·4H2O (1a·2THF·4H2O), (ii) [n-BuCpZr(OH2)3]2(μ2-OH)2(OSO2C8F17)4·6H2O (2a·6H2O), and (iii) [t-BuCpZr(OH2)3]2(μ2-OH)2(OSO2C8F17)4·2C3H6O·8H2O (3a·2C3H6O·8H2O). The ligands of water and organic molecules in the complexes originated from the moist air and solvent during their recrystallization. These complexes were characterized with different techniques, and found to show water tolerance, air/thermal stability as well as strong Lewis acidity. Moreover, the complexes showed highly catalytic activity in various reactions of C–C bond formation. With good recyclability, they should find wide applications in organic chemistry.
- Zhang, Xiaohong,Xu, Xinhua,Li, Ningbo,Liang, Zhiwu,Tang, Zilong
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supporting information
p. 1926 - 1932
(2018/03/21)
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- Synergic "click" Boronate/Thiosemicarbazone System for Fast and Irreversible Bioorthogonal Conjugation in Live Cells
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Fast, high-yielding, and selective bioorthogonal "click" reactions employing nontoxic reagents are in high demand for their great utility in the conjugation of biomolecules in live cells. Although a number of click reactions were developed for this purpose, many are associated with drawbacks and limitations that justify the development of alternative systems for both single- or dual-labeling applications. Recent reports have highlighted the potential of boronic ester formation as a bioorthogonal click reaction between abiotic boronic acids and diols. Boronic ester formation is a fast dehydrative process; however it is intrinsically reversible in aqueous medium. We designed and optimized a synergic system based on two bifunctional reagents, a thiosemicarbazide-functionalized nopoldiol and an ortho-acetyl arylboronic acid. Both reagents were shown to be chemically stable and nontoxic to HEK293T cells at concentrations as high as 50 μM. The resulting boronate/thiosemicarbazone adduct is a medium-sized ring that forms rapidly and irreversibly without any catalyst at low μM concentrations, in neutral buffer, with a rate constant of 9 M-1 s-1 as measured by NMR spectroscopy. Control experiments in the presence of competing boronic acids showed no crossover side-products and confirmed the stability and lack of reversibility of the boronate/thiosemicarbazone conjugates. Formation of the conjugates is not affected by the presence of biological diols such as fructose, glucose, and catechol, and the thiosemicarbazide-functionalized nopoldiol is inert to aldehyde electrophiles of the sort found on protein-bound glyoxylyl units. The suitability of this system in the cell-surface labeling of live cells was demonstrated using a SNAP-tag approach to install the boronic acid reagent onto the extracellular domain of the Beta-2 adrenergic receptor in HEK293T cells, followed by incubation with the optimal thiosemicarbazide-functionalized nopoldiol reagent labeled with fluorescein dye. Successful visualization by fluorescence microscopy was possible with a reagent concentration as low as 10 μM, thus confirming the potential of this system in biological applications.
- Akgun, Burcin,Li, Caishun,Hao, Yubin,Lambkin, Gareth,Derda, Ratmir,Hall, Dennis G.
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supporting information
p. 14285 - 14291
(2017/10/17)
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- Enantioselective Palladium(II)-Catalyzed Intramolecular Aminoarylation of Alkenes by Dual N?H and Aryl C?H Bond Cleavage
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An asymmetric palladium-catalyzed intramolecular oxidative aminoarylation of alkenes has been developed with quinoline–oxazoline chiral ligands and Ag2CO3 as the oxidant. Various indolines containing a quaternary stereogenic center were synthesized in high yield with excellent enantioselectivity. Preliminary mechanistic studies suggest that the addition of a catalytic amount of phenylglyoxylic acid significantly accelerates the reaction and slightly enhances the enantioselectivity.
- Zhang, Wen,Chen, Pinhong,Liu, Guosheng
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supporting information
p. 5336 - 5340
(2017/04/27)
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- Facile synthesis of 1-naphthols through a copper-catalyzed arylation of methyl ketones with o-bromoacetophenones
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The coupling reactions of simple methyl ketones with o-bromoacetophenones and subsquential cyclization reactions were realized to produce a range of 1-naphthols. These cascade reactions were initiated by a rare Cu-catalyzed arylation reaction of methyl ketones with aromatic bromides.
- Lou, Zhen-Bang,Pang, Xin-Long,Chen, Chao,Wen, Li-Rong,Li, Ming
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supporting information
p. 1231 - 1235
(2015/12/30)
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- Impact of electronic modification of the chelating benzylidene ligand in cis-dichloro-configured second-generation olefin metathesis catalysts on their activity
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A series of electronically modified second-generation cis-dichloro ruthenium ester chelating benzylidene complexes was prepared, characterized, and benchmarked in a typical ring-opening metathesis polymerization (ROMP) experiment. The electronic tuning of the parent chelating benzylidene ligand (2-ethyl ester benzylidene) was achieved by substitution at the 4- and 5-positions with electron-withdrawing nitro or electron-donating methoxy groups. The effect of the electronic tuning on the cis-trans isomerization process was studied experimentally and theoretically. Density functional theory calculations clearly revealed the influence of electronic modification on the relative stability between the cis and trans isomers, which is decisive for the activity of the studied compounds as initiators in ROMP.
- Pump, Eva,Poater, Albert,Zirngast, Michaela,Torvisco, Ana,Fischer, Roland,Cavallo, Luigi,Slugovc, Christian
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supporting information
p. 2806 - 2813
(2014/06/24)
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- Synthesis and structure of an air-stable μ2-hydroxy-bridged binuclear complex of bis(methylcyclopentadienyl)dizirconium(IV) perfluorooctanesulfonate and its application in Lewis acid-catalyzed reactions
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Air-stable binuclear complex of bis(methylcyclopentadienyl)zirconium perfluorooctanesulfonate (1a) was successfully synthesized by the reaction of (CH3Cp)2ZrCl2 with C8F 17SO3Ag. The compound 1a was characterized by different techniques and found to have the nature of air-stability, water tolerance, thermally-stability and strong Lewis-acidity. In addition, its solubility was higher than that of our previously reported uninuclear zirconocene bis(perfluorooctanesulfonate). It showed high catalytic efficiency in the Friedel-Crafts acylation of alkyl aryl ethers and the Mannich reaction and could be reused.
- Zhang, Xiaohong,Lou, Cong,Li, Ningbo,Xu, Xinhua,Qiu, Renhua,Yin, Shuangfeng
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supporting information
p. 241 - 245
(2013/11/06)
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- Synthesis and structure-activity relationship studies of O-biphenyl-3-yl carbamates as peripherally restricted fatty acid amide hydrolase inhibitors
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The peripherally restricted fatty acid amide hydrolase (FAAH) inhibitor URB937 (3, cyclohexylcarbamic acid 3′-carbamoyl-6-hydroxybiphenyl-3-yl ester) is extruded from the brain and spinal cord by the Abcg2 efflux transporter. Despite its inability to enter the central nervous system (CNS), 3 exerts profound antinociceptive effects in mice and rats, which result from the inhibition of FAAH in peripheral tissues and the consequent enhancement of anandamide signaling at CB1 cannabinoid receptors localized on sensory nerve endings. In the present study, we examined the structure-activity relationships (SAR) for the biphenyl region of compound 3, focusing on the carbamoyl and hydroxyl groups in the distal and proximal phenyl rings. Our SAR studies generated a new series of peripherally restricted FAAH inhibitors and identified compound 35 (cyclohexylcarbamic acid 3′-carbamoyl-5- hydroxybiphenyl-3-yl ester) as the most potent brain-impermeant FAAH inhibitor disclosed to date.
- Moreno-Sanz, Guillermo,Duranti, Andrea,Melzig, Laurin,Fiorelli, Claudio,Ruda, Gian Filippo,Colombano, Giampiero,Mestichelli, Paola,Sanchini, Silvano,Tontini, Andrea,Mor, Marco,Bandiera, Tiziano,Scarpelli, Rita,Tarzia, Giorgio,Piomelli, Daniele
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p. 5917 - 5930
(2013/08/23)
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- Asymmetric synthesis of (-)-9-epi-metazocine
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(-)-9-epi-Metazocine was synthesized through an Evans syn aldol reaction, ring-closing metathesis reaction and intramolecular radical cyclization. Georg Thieme Verlag Stuttgart · New York.
- Chen, Qiang,Huo, Xing,Zheng, Huaiji,She, Xuegong
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supporting information; experimental part
p. 1349 - 1352
(2012/07/13)
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- Indenone Derivative and Pharmaceutical Composition Comprising Same
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An indenone derivative of formula (1) is effective in enhancing the activity of osteoblastic cells and inhibiting bone resorption by osteoclastic cells, and a pharmaceutical composition comprising the indenone derivative or a pharmaceutically acceptable salt thereof is useful for preventing or treating bone diseases such as osteoporosis.
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Page/Page column 45-46
(2012/09/05)
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- INDENONE DERIVATIVE AND PHARMACEUTICAL COMPOSITION COMPRISING SAME
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An indenone derivative of formula (1) is effective in enhancing the activity of osteoblastic cells and inhibiting bone resorption by osteoclastic cells, and a pharmaceutical composition comprising the indenone derivative or a pharmaceutically acceptable salt thereof is useful for preventing or treating bone diseases such as osteoporosis.
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Page/Page column 111-112
(2011/04/18)
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- SMALL MOLECULE COMPOUNDS FOR STEM CELL DIFFERENTIATION
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Methods and small molecule compounds for stem cell differentiation are provided. One example of a class of compounds that may be used is represented by the compound having the structure IA or IB in the form of free base or a pharmaceutically acceptable salt, hydrate, solvate or N-oxide thereof. R1 is independently hydrogen or (C1-C6)alkyl; R2 is independently hydrogen, (C1-C6)alkyl, aryl, or heteroaryl; R2' is independently hydrogen, (C1-C6)alkyl, CF3 or C2F5; R3 is independently (C1-C6)alkyl, aryl, 2-tetrahydrofuryhnethyl, an aliphatic tertiary amine, or 4-methoxybenzyl; or R2 and R3 may be joined together to form a 5 or 6 member ring lactone; R4 is independently hydrogen, (C1-C6)alkyl, a 2- or 4-R5-substituted aromatic ring selected from a 4-R5-phenyl or a 2-R5-5-pyridyl, aryl, heteroaryl, aliphatic tertiary amine or halogen; and R5, R5', R6, R6', R7, R7' are each independently hydrogen, (C1-C6)alkyl, aryl, optionally substituted phenyl, heteroaryl, a heterocyclic ring, an aliphatic tertiary amine, or halogen.
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Page/Page column 79; 80
(2010/04/25)
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- SUBSTITUTED IMIDAZOLONE DERIVATIVES, PREPARATIONS AND USES
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The present invention relates to polysubstituted imidazolone derivatives, to the pharmaceutical compositions comprising them and to the therapeutic uses thereof in the human and animal health fields. The present invention also relates to a process for preparing these derivatives.
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Page/Page column 59-60
(2010/02/16)
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- High-throughput discovery of mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) inhibitors using click chemistry
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A ~500-member library of bidentate inhibitors against protein tyrosine phosphatases (PTPs) was rapidly assembled using click chemistry. Subsequent high-throughput screening had led to the discovery of highly potent (K i as low as 150 nM) and se
- Tan, Lay Pheng,Wu, Hao,Yang, Peng-Yu,Kalesh, Karunakaran A.,Zhang, Xiaohua,Hu, Mingyu,Srinivasan, Rajavel,Yao, Shao Q.
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supporting information; experimental part
p. 5102 - 5105
(2010/03/24)
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- Atropisomeric bisoxazoline ligands with a bridge across the 5,5′-position of biphenyl for asymmetric catalysis
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A new family of atropisomeric bisoxazoline ligands 2 with a bridge across the 5,5′-position of biphenyl has been developed. The axial chirality of this type of ligands can be retained by macro-ring strain produced by 5,5′-linkage of biphenyls even without
- Wang, Feijun,Zhang, Yong Jian,Wei, Hao,Zhang, Jiaming,Zhang, Wanbin
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p. 4083 - 4086
(2008/02/03)
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- Highly enantioselective Pd(II)-catalyzed Wacker-type cyclization of 2-allylphenols by use of bisoxazoline ligands with axis-unfixed biphenyl backbone
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A series of axis-unfixed bisoxazoline ligands with different steric and electronic properties has been synthesized. Due to the different steric interactions, the ligands afforded only one of the two possible diastereomeric Pd(II)-complexes upon metal coor
- Wang, Feijun,Zhang, Yong Jian,Yang, Guoqiang,Zhang, Wanbin
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p. 4179 - 4182
(2008/02/05)
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- LiClO4-acyl anhydrides complexes as powerful acylating reagents of aromatic compounds in solvent free conditions
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The Friedel-Crafts acylation of various activated benzenes is smoothly carried out with acyl anhydrides in the presence of 2 equiv. of LiClO4, as reaction promoter, under solventless conditions.
- Bartoli, Giuseppe,Bosco, Marcella,Marcantoni, Enrico,Massaccesi, Massimo,Rinaldi, Samuele,Sambri, Letizia
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p. 6331 - 6333
(2007/10/03)
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- Synthesis of (±)-Penlanfuran
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The title compound was efficiently synthesized from 3-furoic acid and 3-bromoanisole via the Birch reduction.
- Takano, Daisuke,Fukunaga, Yuki,Doe, Matsumi,Yoshihara, Kazuo,Kinoshita, Takamasa
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p. 1111 - 1114
(2007/10/03)
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- POTENTIAL CNS ACTIVE 1-ARYL-2-AMINO-1-ETHANOL DERIVATIVES
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New N-(picolyl)-2-(methylamino)-1-aryl-1-ethanols (I) and their O-acyl derivatives (II) were synthesized.Their dopaminomimetic and antidepressant biological activities were examined and compared with the activities of N-(2-aminobenzyl)-2-(methylamino)-1-aryl-1-ethanols (III).It was established that in the reaction of N- methylamine (2) and styryl oxide, the two directions of the splitting of the epoxide ring give rise to two different products that were isolated and identified in the form of their O-acetyl derivatives (13 and 15, respectively).
- Zara-Kaczian, Erzsebet,Deak, Gyula,Gyoergy, Lajos
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p. 441 - 454
(2007/10/02)
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