- First and mild synthesis of fluorene-9-malonic acid and some substituted derivatives via the intramolecular hydroarylation of 2-phenylbenzylidenemalonic acids
-
Hitherto unknown fluorene-9-malonic acid and some substituted derivatives were easily synthesized in very mild conditions through the intramolecular hydroarylation of 2-phenylbenzylidenemalonic acids issued from the corresponding biphenylcarboxaldehydes.
- Chosson, Elizabeth,Rochais, Christophe,Legay, Remi,Santos, Jana Sopkova De Oliveira,Rault, Sylvain,Dallemagne, Patrick
-
-
Read Online
- Direct dehydrogenative arylation of benzaldehydes with arenes using transient directing groups
-
The utilization of the transient directing strategy into the direct oxidative dehydrogenative arylation of aldehydes with arenes was reported for the first time. Featured by mild reaction conditions, good functional group compatibility, and great regiosel
- Wang, Da-Yu,Guo, Shi-Huan,Pan, Gao-Fei,Zhu, Xue-Qing,Gao, Ya-Ru,Wang, Yong-Qiang
-
-
Read Online
- A Photochemical Intramolecular C-N Coupling Toward the Synthesis of Benzimidazole-Fused Phenanthridines
-
Herein, we report a direct photochemical dehydrogenative C-N coupling of unactivated C(sp2)-H and N(sp2)-H bonds. The catalysts or additive-free transformation of 2-([1,1′-biphenyl]-2-yl)-1H-benzo[d]imidazole to benzo[4,5]imidazo[1,2-f]phenanthridine was achieved at ~350 nm of irradiation via ?-hydrogen abstraction. DFT calculations helped to understand that the N-H···πinteraction was essential for the reaction to proceed at a lower energy than expected.
- Bera, Shyamal Kanti,Boruah, Palash J.,Parida, Shraddha Saraswati,Paul, Amit K.,Mal, Prasenjit
-
-
Read Online
- Synthesis of Difluoromethylated and Phosphorated Spiro[5.5]trienones via Dearomative Spirocyclization of Biaryl Ynones
-
Copper- or silver-catalyzed cascade radical addition/dearomative spirocyclization of biaryl ynones with fluoroalkyl bromides or diethylphosphite has been realized for the first time. This method provides a novel and step-economical protocol for the divergent synthesis of a wide range of difluoromethylated or monofluoromethylated and phosphorated spiro[5.5]trienones in moderate to high yields.
- Zhang, Yan,Zhang, Junhua,Hu, Boyue,Ji, Mingming,Ye, Shangyi,Zhu, Gangguo
-
-
Read Online
- Chromium-Catalyzed Selective Cross-Electrophile Coupling between Unactivated C(aryl)-F and C(aryl)-O Bonds
-
Chemically inert C(aryl)-F bonds have rarely been used to couple with other unactivated bonds, and this remains a challenge because of the difficulty of the successive cleavage of two unactivated bonds by metal catalysis. We report here the chromium-catalyzed cleavage of chemically inert C(aryl)-F bonds for coupling with unactivated C(aryl)-O bonds, allowing cross-electrophile coupling between unreactive aryl fluorides and aryl esters to be achieved in high regio- and chemoselectivity. The reactive Cr, which was formed in situ by reducing CrCl2, enables cleavage of the o-C(aryl)-F bonds to afford monovalent and quartet cyclochromate; subsequent bipyridyl-enabled insertion into the ester C(aryl)-O bond followed by reductive elimination allowed the orthogonal coupling of these two different and unactivated bonds. Mechanistic studies indicate that the bipyridyl ligand greatly enhances the reactivity of Cr in the cleavage of C(aryl)-O bonds, and the second oxidative addition may occur sluggishly compared with the reductive elimination in the catalytic cycle.
- Fan, Fei,Zhao, Lixing,Luo, Meiming,Zeng, Xiaoming
-
supporting information
p. 561 - 568
(2022/03/15)
-
- K2S2O8-promoted radical trifluoromethylthiolation/spirocyclization for the synthesis of SCF3?featured spiro[5,5]trienones
-
A direct and efficient strategy for the trifluoromethylthiolation and dearomatization of biaryl ynones with stable and readily available AgSCF3 has been developed. The reaction occurs smoothly in the presence of K2S2O8 via a 6-exo-trig radical cyclization, providing a variety of SCF3-containing spiro [5,5]trienones in good yields.
- Dai, Peng,Li, Bing,Shen, Liu-Yu,Sun, Yu,Wang, Yu-Qi,Yang, Wen-Chao
-
supporting information
(2022/01/24)
-
- Electrochemical Decarboxylative Cyclization of α-Amino-Oxy Acids to Access Phenanthridine Derivatives
-
Phenanthridines are a class of useful heterocycles in the field of drug development. In this work, a method via electrochemical decarboxylative cyclization of α-amino-oxy acids to access phenanthridine derivatives was developed. This reaction proceeded th
- Zhan, Yanling,Dai, Changhui,Zhu, Zitong,Liu, Ping,Sun, Peipei
-
supporting information
(2022/02/07)
-
- Gold Catalysts Can Generate Nitrone Intermediates from a Nitrosoarene/Alkene Mixture, Enabling Two Distinct Catalytic Reactions: A Nitroso-Activated Cycloheptatriene/Benzylidene Rearrangement
-
Gold-catalyzed reactions of cycloheptatrienes with nitrosoarenes yield nitrone derivatives efficiently. This reaction sequence enables us to develop gold-catalyzed aerobic oxidations of cycloheptatrienes to afford benzaldehyde derivatives using CuCl and nitrosoarenes as co-catalysts (10-30 mol %). Our density functional theory calculations support a novel nitroso-activated rearrangement, tropylium → benzylidene. With the same nitrosoarenes, we developed their gold-catalyzed [2 + 2 + 1]-annulations between nitrosobenzene and two enol ethers to yield 5-alkoxyisoxazolidines using 1,4-cyclohexadienes as hydrogen donors.
- Cheng, Mu-Jeng,Kardile, Rahul Dadabhau,Kuo, Tung-Chun,Liu, Rai-Shung,More, Sayaji Arjun
-
p. 5506 - 5511
(2021/07/31)
-
- Design and development of FGF-23 antagonists: Definition of the pharmacophore and initial structure-activity relationships probed by synthetic analogues
-
Hereditary hypophosphatemic disorders, TIO, and CKD conditions are believed to be influenced by an excess of Fibroblast Growth Factor-23 (FGF-23) which activates a binary renal FGFRs / α-Klotho complex to regulate homeostatic metabolism of phosphate and vitamin D. Adaptive FGF-23 responses from CKD patients with excess FGF-23 frequently lead to increased mortality from cardiovascular disease. A reversibly binding small molecule therapeutic has yet to emerge from research and development in this area. Current outcomes described in this work highlight efforts related to lead identification and modification using organic synthesis of strategic analogues to probe structure-activity relationships and preliminarily define the pharmacophore of a computationally derived hit obtained from virtual high-throughput screening. Synthetic strategies for the initial hit and analogue preparation, as well as preliminary cellular in vitro assay results highlighting sub micromolar inhibition of the FGF-23 signaling sequence at a concentration well below cytotoxicity are reported herein.
- Downs, Ryan P.,Xiao, Zhousheng,Ikedionwu, Munachi O.,Cleveland, Jacob W.,Lin Chin, Ai,Cafferty, Abigail E.,Darryl Quarles,Carrick, Jesse D.
-
supporting information
(2020/11/30)
-
- “TPG-lite”: A new, simplified “designer” surfactant for general use in synthesis under micellar catalysis conditions in recyclable water
-
Using the oxidized, carboxylic acid-containing form of MPEG-750, esterification with racemic vitamin E affords a new surfactant (TPG-lite) that functions as an enabling, nanoreactor-forming amphiphile for use in many types of important reactions in synthesis. The presence of a single ester bond is suggestive of simplified treatment as a component of (eventual) reaction waste water, after recycling. Many types of reactions, including aminations, Suzuki-Miyaura, SNAr, and several others are compared directly with TPGS-750-M, leading to the conclusion that TPG-lite can function as an equivalent nanomicelle-forming surfactant in water. Prima facie evidence amassed via DLS and cryo-TEM analyses support these experimental observations. In silico evaluations of the aquatic toxicity and carcinogenicity of TPG-lite indicate that it is safe to use.
- Thakore, Ruchita R.,Takale, Balaram S.,Hu, Yuting,Ramer, Selene,Kostal, Jakub,Gallou, Fabrice,Lipshutz, Bruce H.
-
-
- Alkylative Dearomatization by Using an Unactivated Aryl Nitro Group as a Leaving Group: Access to Diversified Alkylated Spiro[5.5]trienones
-
The cleavage of an unactivated aryl nitro group triggered by alkyl radicals enables a dearomative cyclization, affording diversified alkylated spiro[5.5]trienones in good yields. Using readily available compounds (toluene and analogues, alkanes, ethers, ketones, etc.) as alkylating reagents, various alkyls have been implanted into the spirocycles via C(sp3)-H and Ar-NO2 bond activation with high functional group tolerance. This protocol provides a distinct method for the activation of the aryl nitro group.
- Xia, Dong,Duan, Xin-Fang
-
supporting information
p. 2548 - 2552
(2021/05/05)
-
- DTBP-Mediated Cascade Spirocyclization and Dearomatization of Biaryl Ynones: Facile Access to Spiro[5.5]trienones through C(sp3)?H Bond Functionalization
-
Oxidative radical cascade spirocyclization and dearomatization of biary ynones with a variety of hydrocarbons including toluenes, ethers, ketones, and alkanes has been developed to construct alkyl substituted spiro[5.5]trienones.
- Dong, Sa,Li, Bing,Meng, Fei,Shen, Liu-Yu,Si, Wei-Jie,Yang, Wen-Chao,Zhang, Ming-Ming
-
supporting information
p. 4465 - 4468
(2021/08/30)
-
- Electrochemical Trifluoromethylthiolation and Spirocyclization of Alkynes with AgSCF3: Access to SCF3-Containing Spiro[5,5]trienones
-
A novel and efficient strategy for trifluoromethylthiolation and dearomatization of activated alkynes with stable and readily available AgSCF3 has been developed. Reported herein is the unprecedented electrochemical generation of the SCF3 radical in the absence of persulfate for the synthesis of SCF3-containing spiro[5,5]trienones in good yields via a 6-exo-trig radical cyclization.
- Yang, Wen-Chao,Zhang, Ming-Ming,Sun, Yu,Chen, Cai-Yun,Wang, Lei
-
supporting information
p. 6691 - 6696
(2021/09/08)
-
- Biphenyl Cyclobutenone Photoelectrocyclizations
-
In this work, we demonstrate that readily available conjugated bis-aryl cyclobutenones undergo photoelectrocyclization reactions to give the corresponding dihydrophenanthrene cyclobutanones when exposed to 350 nm light, TFA, and TMSCl. We have also found that cyclobutenone electrocyclizations and cycloreversions are in equilibrium.
- Dai, Changhang,Rainier, Jon D.,Schwartz, Zach,Song, Changqing,Zhao, Xuchen
-
p. 15164 - 15176
(2021/10/20)
-
- Metal-Free Electrochemical Coupling of Vinyl Azides: Synthesis of Phenanthridines and β-Ketosulfones
-
We reported an efficient and environmentally benign electrochemical synthesis of phenanthridines by oxidative coupling of vinyl azides with sodium azide or benzenesulfonyl hydrazides, for the first time. The reaction conditions are mild, and no additional metal-catalyst or exogenous oxidants are needed. The protocol has broad substrate scope and high functional group tolerance. Furthermore, this green electrochemical procedure can be readily extended to the synthesis of β-ketosulfones. Gram scale reactions further demonstrate the practicability.
- Chen, Qianjin,Kong, Xianqiang,Li, Guodong,Liang, Qi,Lin, Long,Xu, Bo,Yu, Ke
-
supporting information
p. 6135 - 6145
(2020/10/06)
-
- FIBROBLAST GROWTH FACTOR 23 ANTAGONISTS AND RELATED COMPOSITIONS AND METHODS
-
This disclosure relates to small molecule inhibitors of Fibroblast growth factor 23 (FGF-23) and related compositions and methods of treatment.
- -
-
Page/Page column 25-26; 36
(2019/05/15)
-
- Ruthenium(0)-Catalyzed Cross-Coupling of Anilines with Organoboranes by Selective Carbon-Nitrogen Cleavage
-
Selective activation of neutral carbon-nitrogen bonds is of great synthetic importance, because amines are among the most prevalent motifs across organic and bioactive molecules. Herein, we report the Ru(0)-catalyzed selective cleavage of neutral C(aryl)-N bonds in generic aniline derivatives enabled by a combination of Ru3(CO)12 and an imino auxiliary. These mild conditions provide a direct route to high-value biaryl ketones and biaryl aldehydes after facile in situ hydrolysis. A broad range of organoboranes and anilines can be coupled with high C-N cleavage selectivity. Most crucially, the reaction achieves exquisite selectivity for activation of C(aryl)-N bonds in the presence of typically more kinetically favorable C(aryl)-H bonds. The method provides a strategy for the construction of functionalized terphenyls by exploiting orthogonal properties of the Ru(0) catalyst system and traceless nucleophilic properties of anilines.
- Zhao, Qun,Zhang, Jin,Szostak, Michal
-
p. 8171 - 8177
(2019/08/22)
-
- Interplay between n→π? Interactions and Dynamic Covalent Bonds: Quantification and Modulation by Solvent Effects
-
Orbital donor-acceptor interactions play critical roles throughout chemistry, and hence, their regulation and functionalization are of great significance. Herein we demonstrate for the first time the investigation of n→π? interactions through the strategy of dynamic covalent chemistry (DCC), and we further showcase its use in the stabilization of imine. The n→π? interaction between donor X and acceptor aldehyde/imine within 2-X-2′-formylbiphenyl derivatives was found to significantly influence the thermodynamics of imine exchange. The orbital interaction was then quantified through imine exchange, the equilibrium of which was successfully correlated with the difference in natural bond orbital stabilization energy of n→π? interactions of aldehyde and its imine. Moreover, the examination of solvent effects provided insights into the distinct feature of the modulation of n→π? interaction with aprotic and protic solvents. The n→π? interaction involving imine was enhanced in protic solvents due to hydrogen bonding with the solvent. This finding further enabled the stabilization of imine in purely aqueous solution. The strategies and results reported should find application in many fields, including molecular recognition, biological labeling, and asymmetric catalysis.
- Zheng, Hao,Ye, Hebo,Yu, Xiaoxia,You, Lei
-
supporting information
p. 8825 - 8833
(2019/06/13)
-
- A highly efficient and recyclable NiCl2(dppp)/PEG-400 system for Suzuki-Miyaura reaction of aryl chlorides with arylboronic acids
-
NiCl2(dppp) in PEG-400 is shown to be a highly efficient catalyst for Suzuki-Miyaura coupling of aryl chlorides with arylboronic acids. The reaction could be conducted at 100 °C using K3PO4 as base, yielding a variety of biaryls in good to excellent yields. The isolation of the products was readily performed by extraction with petroleum ether and NiCl2(dppp)/PEG-400 system could be easily recycled and reused up to five times without significant loss of activity. Our system not only avoids the use of easily volatile and toxic dioxane or toluene as a solvent but also solves the basic problem of nickel catalyst reuse.
- Liao, Yang,Yang, Weisen,Wei, Ting,Cai, Mingzhong
-
supporting information
p. 1134 - 1142
(2019/04/10)
-
- Base-Free Suzuki–Miyaura Coupling Reaction Using Palladium(II) Supported Catalyst in Water
-
Abstract: The carbon–carbon bond formation via Suzuki–Miyaura reaction was performed in water as green solvent. Pd(OAc)2(PPh3)2 supported on magnesium hydroxide and cerium carbonate hydroxide composite was prepared and characterized by various techniques. The cross-coupling reaction of aryl halides carried out in water using mild conditions. The effects of temperature, solvents, the amount of catalyst and leaving groups were studied to find the optimization conditions for cross-coupling reaction. Various aryl halides were smoothly transformed into the biaryls in good yields. In addition, the catalyst also exhibited stability and catalytic performance in the cross-coupling of aryl halides. Graphical Abstract: [Figure not available: see fulltext.] A new approach is developed for carbon–carbon bond formation via Suzuki–Miyaura reaction.2 Pd(OAc)2(PPh3)2?supported on mixed magnesium hydroxide and cerium carbonate hydroxide were prepared and characterized by XRD, XPS, SEM–EDX techniques. The cross-coupling reaction of aryl halides can be carried out in water and under mild conditions (80 °C).
- Tomar, Ravi,Singh, Nidhi,Kumar, Neeraj,Tomar, Vartika,Chandra, Ramesh
-
-
- Sustainable Ligand-Free, Palladium-Catalyzed Suzuki–Miyaura Reactions in Water: Insights into the Role of Base
-
A simple and efficient system was developed for the ligand-free Pd-catalyzed Suzuki–Miyaura reaction in water under mild conditions. Quaternary ammonium hydroxides with long chains were found to be very suitable bases. This ligand-free Pd-catalyzed Suzuki–Miyaura reaction showed improved durability in water with Pd loadings decreased to ppm level. Bases were shown to stabilize active palladium species in addition to acting as a base during the catalytic process. In the catalytic system with a strong base, the soluble active PdII ion exhibited anti-reduction properties, which prevented aggregation and deactivation of Pd species. The entire catalytic system could be recycled after separating the product by simple filtration. The water-compatible and air-stable effective catalytic protocol described herein represents an attractive and green synthetic advance in Suzuki–Miyaura couplings.
- Wang, Yanyan,Liu, Yuanyuan,Zhang, Wei-qiang,Sun, Huaming,Zhang, Kan,Jian, Yajun,Gu, Quan,Zhang, Guofang,Li, Jiyang,Gao, Ziwei
-
p. 5265 - 5273
(2019/11/29)
-
- Modular Design of Fluorescent Dibenzo- and Naphtho-Fluoranthenes: Structural Rearrangements and Electronic Properties
-
A library of 12 dibenzo- and naphtho-fluoranthene polycyclic aromatic hydrocarbons (PAHs) with MW = 302 (C24H14) was synthesized via a Pd-catalyzed fluoranthene ring-closing reaction. By understanding the various modes by which the palladium migrates during the transformation, structural rearrangements were bypassed, obtaining pure PAHs in high yields. Spectroscopic and electrochemical characterization demonstrated the profound diversity in the electronic structures between isomers. Highlighting the significant differences in emission of visible light, this library of PAHs will enable their standardization for toxicological assessment and potential use as optoelectronic materials.
- Mohammad-Pour, Gavin S.,Ly, Richard T.,Fairchild, David C.,Burnstine-Townley, Alex,Vazquez-Molina, Demetrius A.,Trieu, Khang D.,Campiglia, Andres D.,Harper, James K.,Uribe-Romo, Fernando J.
-
supporting information
p. 8036 - 8053
(2018/05/31)
-
- Imidazolium-based ionic liquid functionalized reduced graphene oxide supported palladium as a reusable catalyst for Suzuki-Miyaura reactions
-
A novel palladium immobilized on reduced graphene oxide heterogeneous catalyst was prepared. The reduced graphene oxide was functionalized by imidazolium-based ionic liquids containing polyethylene glycol monomethyl ether moieties. The prepared catalyst can achieve Suzuki-Miyaura reactions efficiently in green solvents under mild conditions and could be recycled for five catalytic runs without the loss of activity.
- Shi, Xin,Cai, Chun
-
supporting information
p. 2364 - 2367
(2018/02/19)
-
- Synthesis of Enantiomerically Pure and Racemic Benzyl-Tethered Ru(II)/TsDPEN Complexes by Direct Arene Substitution: Further Complexes and Applications
-
The use of a direct arene-exchange method for the synthesis of benzyl-tethered arene/Ru/TsDPEN complexes for use in asymmetric transfer hydrogenation is reported. A series of complexes tethered through a three-carbon linear chain was also prepared. The arene-exchange approach significantly simplifies the synthetic approach to this class of catalyst and permits the ready formation of modified analogues. The approach also provides a route to racemic catalysts for use in general reductions with either hydrogen or transfer hydrogenation.
- Soni, Rina,Jolley, Katherine E.,Gosiewska, Silvia,Clarkson, Guy J.,Fang, Zhijia,Hall, Thomas H.,Treloar, Ben N.,Knighton, Richard C.,Wills, Martin
-
-
- Chromium-Catalyzed, Regioselective Cross-Coupling of C-O Bonds by Using Organic Bromides as Reactants
-
We report a chromium-catalyzed cross-coupling of C-O bonds with widely accessible organic bromides as reactants for the preparation of ortho -arylated or -alkylated aromatic aldehydes at room temperature. The use of metallic magnesium is essential for the reaction to occur, giving it an advantage over previous reactions involving Grignard reagents that have to be prepared separately from organic halides before the coupling.
- Tang, Jinghua,Luo, Meiming,Zeng, Xiaoming
-
supporting information
p. 2577 - 2580
(2017/09/28)
-
- Low-Valent, High-Spin Chromium-Catalyzed Cleavage of Aromatic Carbon-Nitrogen Bonds at Room Temperature: A Combined Experimental and Theoretical Study
-
The cleavage of aromatic carbon-nitrogen bonds catalyzed by transition metals is of high synthetic interest because such bonds are common in organic chemistry. However, few metal catalysts can be used to selectively break C(aryl)-N bonds in electronically neutral molecules. We report here the first low-valent, high-spin chromium-catalyzed cleavage of C(aryl)-N bonds in electronically neutral aniline derivatives at room temperature. By using simple and inexpensive chromium(II) chloride as precatalyst, accompanied by an imino auxiliary, the selective arylative and alkylative C-C coupling of C(aryl)-N bonds can be achieved. Crossover experiments indicate that a low-valent chromium species, formed in situ by reduction of CrCl2 with Grignard reagent, is responsible for the catalytic cleavage of C(aryl)-N bonds. DFT calculations show that facile insertion of the C(aryl)-N bond by chromium(0) can take place in a high-spin quintet (S = 2) ground state, whereas the lower-spin singlet (S = 0) and triplet (S = 1) states are inaccessible in energy. It was found that both donation of the sole paired d electrons in the d6 shell of high-spin chromium(0) to the antibonding orbital of the C(aryl)-N bond and the nitrogen ligating interaction to the metal center with its lone pair play important roles in the cleavage of the C(aryl)-N bond by the zerovalent chromium species.
- Cong, Xuefeng,Fan, Fei,Ma, Pengchen,Luo, Meiming,Chen, Hui,Zeng, Xiaoming
-
p. 15182 - 15190
(2017/10/31)
-
- Gold-Catalyzed Oxidation Terminal Alkyne: An Approach to Synthesize Substituted Dihydronaphthalen-2(1H)-ones and Phenanthrenols
-
A facile gold-catalyzed oxidation terminal alkynes to synthesize substituted dihydronaphthalen-2(1H)-ones 3 and phenanthrenols 5 was realized. Various useful structures and drug precursors were generated in up to 99% yield under mild condition and low catalyst loading.
- Ling, Hui-Bo,Chen, Zi-Sheng,Yang, Fang,Xu, Bin,Gao, Jin-Ming,Ji, Kegong
-
p. 7070 - 7076
(2017/07/15)
-
- Silver-Catalyzed Tandem C=C Bond Hydroazidation/Radical Addition/Cyclization of Biphenyl Acetylene: One-Pot Synthesis of 6-Methyl Sulfonylated Phenanthridines
-
A silver-catalyzed tandem carbon-carbon triple bond hydroazidation, radical addition, and cyclization of biphenyl acetylene is described under mild conditions, leading to the formation of 6-methyl sulfonylated phenanthridines in good yields. In this novel cascade reaction, most of the atoms are incorporated into the product without cleavage of the C=C bond. Mechanistic studies suggest the reaction should proceed through an iminyl radical reactive intermediate.
- Tang, Jiawei,Sivaguru, Paramasivam,Ning, Yongquan,Zanoni, Giuseppe,Bi, Xihe
-
supporting information
p. 4026 - 4029
(2017/08/14)
-
- (Biphenyl-2-alkyne) derivatives as common precursors for the synthesis of 9-iodo-10-organochalcogen-phenanthrenes and 9-organochalcogen-phenanthrenes
-
In this paper, we report our results on the cyclization of (biphenyl-2-alkyne) derivatives to give two different types of phenanthrene derivatives, 9-iodo-10-organochalcogen-phenanthrenes and 9-organochalcogen-phenanthrenes. The strategy for the synthesis was based on the use of electrophilic cyclization for the preparation of 9-iodo-10-organochalcogen-phenanthrenes and iron(iii) chloride/diorganyl diselenide-mediated intramolecular cyclization to prepare 9-organochalcogen-phenanthrenes. The effects of solvent, temperature, reaction time and stoichiometry on the efficiency of cyclization reactions were investigated. The standard reaction conditions were compatible with many functional groups in the substrates, such as methyl, chlorine, fluorine and methoxyl. This protocol was efficient for diorganyl diselenides and disulfides but ineffective for diorganyl ditellurides. The resulting phenanthrenes were further functionalized through Sonogashira reactions followed by the electrophilic cyclization reaction to give the selenophene-fused aromatic compounds.
- Grimaldi, Tamiris B.,Lutz, Guilherme,Back, Davi F.,Zeni, Gilson
-
p. 10415 - 10426
(2016/11/18)
-
- 4-Aryliden-2-methyloxazol-5(4H)-one as a new scaffold for selective reversible MAGL inhibitors
-
This study reports on a preliminary structure-activity relationship exploration of 4-aryliden-2-methyloxazol-5(4H)-one-based compounds as MAGL/FAAH inhibitors. Our results highlight that this scaffold may serve for the development of selective MAGL inhibi
- Granchi, Carlotta,Rizzolio, Flavio,Bordoni, Vittorio,Caligiuri, Isabella,Manera, Clementina,Macchia, Marco,Minutolo, Filippo,Martinelli, Adriano,Giordano, Antonio,Tuccinardi, Tiziano
-
p. 137 - 146
(2016/01/12)
-
- UV light-mediated difunctionalization of alkenes with CF3SO2Na: Synthesis of trifluoromethyl phenanthrene and anthrone derivatives
-
A metal-free and cost-effective protocol for UV light-mediated difunctionalization of alkenes with CF3SO2Na was developed. This strategy realized the direct formation of Csp3-CF3 and C-C bonds through a proposed
- Li, Bing,Fan, Dan,Yang, Chao,Xia, Wujiong
-
supporting information
p. 5293 - 5297
(2016/07/06)
-
- Regio- and Chemoselective Kumada-Tamao-Corriu Reaction of Aryl Alkyl Ethers Catalyzed by Chromium under Mild Conditions
-
Acting as an environmentally benign synthetic tool, the cross-coupling reactions with aryl ethers via C-O bond activation have attracted broad interest. However, the functionalizations of C-O bonds are mainly limited to nickel catalysis, and selectivity has long been a prominent challenge when several C-O bonds are present in the one molecule. We report here the first chromium-catalyzed selective cross-coupling reactions of aryl ethers with Grignard reagents by the cleavage of C-O(alkyl) bonds. Diverse transformations were achieved using simple, inexpensive chromium(II) precatalyst combining imino auxiliary at room temperature. It offers a new avenue for buildup functionalized aromatic aldehydes with high efficiency and selectivity.
- Cong, Xuefeng,Tang, Huarong,Zeng, Xiaoming
-
supporting information
p. 14367 - 14372
(2015/12/01)
-
- Sustainable Fe-ppm Pd nanoparticle catalysis of Suzuki-Miyaura cross-couplings in water
-
Most of today's use of transition metal-catalyzed cross-coupling chemistry relies on expensive quantities of palladium (Pd). Here we report that nanoparticles formed from inexpensive FeCl3 that naturally contains parts-per-million (ppm) levels of Pd can catalyze Suzuki-Miyaura reactions, including cases that involve highly challenging reaction partners. Nanomicelles are employed to both solubilize and deliver the reaction partners to the Fe-ppm Pd catalyst, resulting in carbon-carbon bond formation. The newly formed catalyst can be isolated and stored at ambient temperatures. Aqueous reaction mixtures containing both the surfactant and the catalyst can be recycled.
- Handa, Sachin,Wang, Ye,Gallou, Fabrice,Lipshutz, Bruce H.
-
p. 1087 - 1091
(2015/09/21)
-
- Polyaniline-anchored palladium catalyst-mediated Mizoroki-Heck and Suzuki-Miyauraa reactions and one-pot Wittig-Heck and Wittig-Suzuki reactions
-
A polyaniline-anchored palladium catalyst was prepared and screened for coupling reactions of aryl halides. The robust and recyclable catalyst was effective in Mizoroki-Heck and Suzuki-Miyaura reactions of aryl bromides and aryl iodides. The catalyst system was further employed for one-pot Wittig-Heck and Wittig-Suzuki combinations to build conjugated compounds in good conversions.
- Patel, Heta A.,Patel, Arun L.,Bedekar, Ashutosh V.
-
-
- Phosphine-Free Suzuki Cross-Coupling Reaction Using an Efficient and Reusable Pd Catalyst in an Aqueous Medium under Microwave Irradiation
-
We report here an improved, highly efficient, and general method for the ligand-free Suzuki cross-coupling reaction to the synthesis of biaryls, bipyridyls, thienylpyridine, and allylphenols. Microwave irradiation of (het)aryl halides and (hetaryl, allyl)arylboronic acid N-methyl-iminodiacetic acid (MIDA) ester, using polyurea microencapsulated palladium catalyst (Pd EnCat 30), gave the coupling adducts 1a-x in excellent yields in just 10-18 min.
- Da Silva, Joaquim F. M.,Yepes Perez, Andres F.,De Almeida, Natália P.
-
supporting information
p. 1995 - 2004
(2015/08/18)
-
- Palladium salt and functional reduced graphene oxide complex: in situ preparation of a generally applicable catalyst for C-C coupling reactions
-
A novel Pd catalyst was designed by affording Pd2+ salt on the surface of functional reduced graphene oxide (FRGO), providing a new cheap and stable in situ prepared palladium catalyst for C-C coupling reactions, including the Heck reaction, Suzuki reaction, C-H bond functionalization reactions of thiophenes, and terminal alkyne C-H activation and homocoupling.
- Wang, Sheng,Hu, Donghua,Hua, Wenwen,Gu, Jiangjiang,Zhang, Qiuhong,Jia, Xudong,Xi, Kai
-
p. 53935 - 53939
(2015/06/30)
-
- Copper catalyzed room temperature lactonization of aromatic C-H bond: A novel and efficient approach for the synthesis of dibenzopyranones
-
We have developed a novel and efficient methodology for the intramolecular aryl C-H oxidative lactonization of 2-arylbenzaldehyde using a low-cost CuCl catalyst and TBHP as the oxidant at room temperature. We applied the methodology to the synthesis of a series of dibenzopyranones.
- Singha, Raju,Dhara, Shubhendu,Ghosh, Munmun,Ray, Jayanta K.
-
p. 8801 - 8805
(2015/03/03)
-
- Catalytic oxidative cyclization of 2′-arylbenzaldehyde oxime ethers under photoinduced electron transfer conditions
-
A series of 2′-arylbenzaldehyde oxime ethers were synthesized and shown to generate the corresponding phenanthridines upon irradiation in the presence of 9,10-dicyanoanthracene in acetonitrile. Mechanistic studies suggest that the oxidative cyclization reaction sequence is initiated by an electron transfer step followed by nucleophilic attack of the aryl ring onto the nitrogen of the oxime ether. A concave downward Hammett plot is presumably the result of a change in charge distribution in the radical cation species with strongly electron-donating substituents that yields a less electrophilic nitrogen atom and a decreased amount of cyclized product. The reaction is selective (no nitrile byproduct is formed unlike other photochemical reactions involving aldoxime ethers) as well as regiospecific when using 2′-aryl groups with metasubstituents, making this reaction a useful alternative for preparing substituted phenanthridines.
- Hofstra, Julie L.,Grassbaugh, Brittany R.,Tran, Quan M.,Armada, Nicholas R.,De Lijser, H. J. Peter
-
p. 256 - 265
(2016/09/09)
-
- Bismuth-catalyzed synthesis of polycyclic aromatic hydrocarbons (PAHs) with a phenanthrene backbone via cyclization and aromatization of 2-(2-arylphenyl)vinyl ethers
-
The reaction of 2-(2-arylphenyl)vinyl ethers in the presence of a catalytic amount of bismuth(III) triflate gave substituted phenanthrenes in excellent yields under mild reaction conditions. The reaction was also applied to the construction of other polycyclic aromatic hydrocarbons (PAHs), such as chrysene, helicene, and pyrene having a phenanthrene backbone, via regioselective cyclization. This method has the advantages of easy availability of the cyclization precursors, operational simplicity, and high reaction efficiency.
- Murai, Masahito,Hosokawa, Naoki,Roy, David,Takai, Kazuhiko
-
supporting information
p. 4134 - 4137
(2014/09/30)
-
- Atom-economic threefold cross-couplings of triarylbismuth reagents with 2-halobenzaldehydes and pot-economic in situ Wittig functionalizations with phosphonium salts
-
In this paper we report an efficient pot-economic methodology for the synthesis of ortho-olefinated biaryls. This has been achieved through an atom-economic threefold cross-coupling of triarylbismuth reagents with 2-halobenzaldehydes followed by pot-economic in situ Wittig olefination. The overall process is a pot-economic straightforward synthesis of ortho-olefinated biaryls from 2-halobenzaldehydes, triarylbismuth reagents and phosphonium salts. This pot-economic approach was applied to the formal synthesis of medicinally important Eupomatilone-6.
- Rao, Maddali L. N.,Dhanorkar, Ritesh J.
-
p. 63792 - 63806
(2015/02/19)
-
- Synthesis of phenanthrenes through copper-catalyzed cross-Coupling of N-tosylhydrazones with terminal alkynes
-
A novel protocol for the synthesis of phenanthrenes through the copper-catalyzed reaction of aromatic tosylhydrazones with terminal alkynes is explored. The reaction proceeds via the formation of an allene intermediate and subsequent six-π-electron cyclization-isomerization, affording phenanthrene derivatives in good yields. The transformation can be performed in two ways:(1)with Ntosylhydrazones derived from [1,1'-biphenyl]-2-carbaldehydes and terminal alkynes as the starting materials and(2)with Ntosylhydrazones derived from aromatic aldehydes and 2-alkynyl biphenyls as the starting materials. This new phenanthrene synthesis uses readily available starting materials and a cheap copper catalyst and has a wide range of functional group compatibility.
- Hossain, Mohammad Lokman,Ye, Fei,Liu, Zhenxing,Xia, Ying,Shi, Yi,Zhou, Lei,Zhang, Yan,Wang, Jianbo
-
p. 8689 - 8699
(2015/01/08)
-
- An efficient and new protocol for phosphine-free Suzuki coupling reaction using palladium-encapsulated and air-stable MIDA boronates in an aqueous medium
-
A simple methodology that uses a system based on polyurea microencapsulated palladium (PdEnCat 30) and aryl or (2-pyridyl) MIDA boronates for Suzuki-Miyaura cross-coupling reactions of (hetero)aryl halides in water-alcohol under phosphine-free conditions was developed. This journal is the Partner Organisations 2014.
- Mendes Da Silva, Joaquim Fernando,Yepes Perez, Andres Felipe,Pinto De Almeida, Natalia
-
p. 28148 - 28155
(2014/07/21)
-
- Cyclometalated Pd(ii) and Ir(iii) 2-(4-bromophenyl)pyridine complexes with N-heterocyclic carbenes (NHCs) and acetylacetonate (acac): Synthesis, structures, luminescent properties and application in one-pot oxidation/Suzuki coupling of aryl chlorides containing hydroxymethyl
-
A series of cyclopalladated 2-(4-bromophenyl)pyridine (bpp) complexes [Pd(bpp)(NHC)Cl] 1-3, [Pd(bpp)(acac)] 4, cyclometalated iridium(iii) complexes [Ir(bpp)2Cl]25 and [Ir(bpp)2(acac)] 6 have been synthesized and characterized. Their detailed structures have been determined by X-ray diffraction and many intermolecular C-H...X (Cl, Br, π) and π...π interactions were found in their crystals. Cyclometalated complexes 1-4 and 6 exhibit luminescence with emission peaks of 390-543 nm in dichloromethane solution under UV irradiation. Their application to coupling reactions of aryl chlorides containing hydroxymethyl was also investigated. An efficient 3/Cu cocatalyzed oxidation/Suzuki reaction for the synthesis of biarylaldehydes from chloro-phenylmethanol and arylboronic acids in air has been developed. In addition, a 6/3-cocatalyzed one-pot reaction of acetylferrocene, (2-amino-5-chlorophenyl)methanol, and arylboronic acids provided 6-aryl-2-ferrocenylquinolines in moderate to good yields.
- Xu, Chen,Li, Hong-Mei,Xiao, Zhi-Qiang,Wang, Zhi-Qiang,Tang, Si-Fu,Ji, Bao-Ming,Hao, Xin-Qi,Song, Mao-Ping
-
p. 10235 - 10247
(2014/06/24)
-
- Palladium-loaded renewable polymer as a green heterogeneous catalyst for cross-coupling reactions under microwave irradiation
-
A new palladium catalyst was prepared by immobilising ligand 2, 2'-dipyridylamine on the backbone of an acidic rosin polymer from gum rosin, on to which palladium(II) was bound via coordination. The catalyst at a low loading of 0.2 mol% was found to be highly effective for Suzuki-Miyaura coupling reactions of aryl halides and arylboronic acids under microwave irradiation in the presence of 1 equiv. of Na2CO3, affording excellent yields of the corresponding biaryls. Moreover, the catalyst exhibited very good recyclability over three cycles.
- Pan, Dan,Wu, Aiqun,Li, Pengfei,Xu, Haitang,Lei, Fuhou,Shen, Liqun
-
p. 715 - 718
(2015/03/03)
-
- Gold-catalyzed 6-exo-dig cycloisomerization: A versatile approach to functionalized phenanthrenes
-
A novel gold-catalyzed 6-exo-dig cycloisomerization of o-propargylbiaryls has been developed that provides ready access to functionalized phenanthrenes in largely good to excellent yields. Notable features of this method are readily available starting materials, mild reaction conditions, and broad substrate scope. Golden cat: A novel gold-catalyzed 6-exo-dig cycloisomerization of o-propargylbiaryls has been developed that provides ready access to functionalized phenanthrenes in largely good to excellent yields. Notable features of this method are readily available starting materials, mild reaction conditions, and broad substrate scope.
- Shu, Chao,Li, Long,Chen, Cheng-Bin,Shen, Hong-Cheng,Ye, Long-Wu
-
supporting information
p. 1525 - 1529
(2014/06/09)
-
- Solvent control of product diversity in palladium-catalyzed addition of arylboronic acid to aryl aldehydes
-
In Pd-catalyzed arylboronic acid addition to aryl aldehydes, the expected carbinol or asymmetrical ether can be obtained as the major product by altering aqueous solvent composition. Exploiting this methodology with 2-formylbiphenyls as reaction partner, a fluorene scaffold can be readily constructed in two steps.
- Das, Tuluma,Chakraborty, Amarnath,Sarkar, Amitabha
-
supporting information
p. 5174 - 5178
(2014/12/10)
-
- Efficient chromium(II)-catalyzed cross-coupling reactions between Csp 2 centers
-
Low-toxicity chromium(II) chloride catalyzes at 25 C within minutes the coupling reactions of various (hetero)arylmagnesium reagents with N-heterocyclic halides, aromatic halogenated ketones or imines, and alkenyl iodides. Remarkably, much lower amounts o
- Steib, Andreas K.,Kuzmina, Olesya M.,Fernandez, Sarah,Flubacher, Dietmar,Knochel, Paul
-
supporting information
p. 15346 - 15349
(2013/11/06)
-
- Discovery of aryl-biphenyl-2-ylmethylpiperazines as novel scaffolds for 5-HT7 ligands and role of the aromatic substituents in binding to the target receptor
-
It has been reported that 5-HT7 receptors are promising targets of depression and neuropathic pain. 5-HT7 receptor antagonists have exhibited antidepressant-like profiles, while agonists have represented potential therapeutics for pain. In the course of our ongoing efforts to discover novel 5-HT7 modulators, we designed an arylpiperazine scaffold with a substituted biphenyl-2-ylmethyl group. A series of biphenyl-2-yl-arylpiperazinylmethanes were then prepared, which showed a broad spectrum of binding affinities to the 5-HT7 receptor depending upon the substituents attached to the biphenyl and aryl functionalities. Among those synthesized compounds, the compounds 1-24 and 1-26 showed the best binding affinities to the 5-HT7 receptor with Ki values of 43.0 and 46.0 nM, respectively. Structure-activity relationship study in conjunction with molecular docking study proposed that the 5-HT7 receptor might have two distinctive hydrophobic binding sites, one specific for aromatic 2-OCH3 substituents within the arylpiperazine and the other for biphenyl methoxy group.
- Kim, Youngjae,Kim, Jeeyeon,Tae, Jinsung,Roth, Bryan L.,Rhim, Hyewhon,Keum, Gyochang,Nam, Ghilsoo,Choo, Hyunah
-
p. 2568 - 2576
(2013/06/26)
-
- Cross dehydrogenative coupling via base-promoted homolytic aromatic substitution (BHAS): Synthesis of fluorenones and xanthones
-
Cross dehydrogenative coupling reactions occurring via base-promoted homolytic aromatic substitutions (BHASs) are reported. Fluorenones and xanthones are readily prepared via CDC starting with readily available ortho-formyl biphenyls and ortho-formyl biphenylethers, respectively. The commercially available and cheap tBuOOH is used as an oxidant. Initiation of the radical chain reaction is best achieved with small amounts of FeCp2 (0.1 or 1 mol %).
- Wertz, Sebastian,Leifert, Dirk,Studer, Armido
-
supporting information
p. 928 - 931
(2013/03/28)
-
- Focused pseudostatic hydrazone libraries screened by mass spectrometry binding assay: Optimizing affinities toward γ-aminobutyric acid transporter 1
-
Mass spectrometric (MS) binding assays, a powerful tool to determine affinities of single drug candidates toward chosen targets, were recently demonstrated to be suitable for the screening of compound libraries generated with reactions of dynamic combinatorial chemistry when rendering libraries pseudostatic. Screening of small hydrazone libraries targeting γ-aminobutyric acid transporter 1 (GAT1), the most abundant γ-aminobutyric acid (GABA) transporter in the central nervous system, revealed two nipecotic acid derived binders with submicromolar affinities. Starting from the biphenyl carrying hit as lead structure, the objective of the present study was to discover novel high affinity GAT1 binders by screening of biphenyl focused pseudostatic hydrazone libraries formed from hydrazine 10 and 36 biphenylcarbaldehydes 11c-al. Hydrazone 12z that carried a 2′,4′-dichlorobiphenyl residue was found to be the most potent binder with low nanomolar affinity (pKi = 8.094 ± 0.098). When stable carba analogues of representative hydrazones were synthesized and evaluated, the best binder 13z was again displaying the 2′,4′- dichlorobiphenyl moiety (pKi = 6.930 ± 0.021).
- Sindelar, Miriam,Lutz, Toni A.,Petrera, Marilena,Wanner, Klaus T.
-
supporting information
p. 1323 - 1340
(2013/04/10)
-
- An efficient microwave-assisted suzuki reaction using a new pyridine-pyrazole/Pd(II) species as catalyst in aqueous media
-
A new pyridine-pyrazole N-N ligand has been conveniently synthesized and characterized by 1H-, 13C-NMR, IR spectroscopies, HRMS and X-ray single-crystal crystallography analyses. The ligand adds to palladium(II) under basic conditions to give high yields of an air-stable and water-soluble complex that was fully characterized by NMR and HRMS. The complex was investigated as a catalyst for the Suzuki reaction in aqueous media under microwave irradiation. The compound proved to be an effective catalyst.
- Shen, Liqun,Huang, Suyu,Nie, Yuanmei,Lei, Fuhou
-
p. 1602 - 1612
(2013/04/10)
-