- Nickel-Catalyzed Ortho-Arylation of Unactivated (Hetero)aryl C-H Bonds with Arylsilanes Using a Removable Auxiliary
-
Ni(II)-catalyzed ortho-arylation of aromatic and heteroaromatic carboxamides with triethoxy(aryl)silanes assisted by a removable bidentate auxiliary is reported. This transformation features a broad substrate scope, good functional group tolerance, and co
- Zhao, Sheng,Liu, Bin,Zhan, Bei-Bei,Zhang, Wei-Dong,Shi, Bing-Feng
-
-
Read Online
- Palladium-catalyzed intramolecular aromatic C-H acylation of 2-arylbenzoyl fluorides
-
The catalytic intramolecular cyclization of acyl fluorides using a Pd(OAc)2/PCy3 system is described. A wide range of 2-arylbenzoyl fluoride derivatives can be used as fluorenone precursors and the reaction proceeds via an intramolecular coupling between aromatic C-H bonds with acyl C-F bonds. The reaction can be applied to the synthesis of indenofluorenedione derivatives and to the construction of other molecules with fivemembered rings.
- Hayakawa, Kazuki,Ikai, Kana,Ogiwara, Yohei,Sakai, Norio,Sakurai, Yuka
-
p. 1882 - 1893
(2021/08/13)
-
- Transition-Metal-Free Synthesis of Phenanthridinones through Visible-Light-Driven Oxidative C–H Amidation
-
The treatment of N-aryl biphenylcarboxamide, 1-chloroanthraquinone (1-Cl-AQN) catalyst, and K2CO3 in CHCl3 under visible light irradiation affords phenanthridinone via radical cyclization. This reaction proceeds under transition-metal-free condition, room temperature, and direct C–H amidation. Mechanistic studies indicate that amidyl radical generation proceeds by visible light induced proton coupled electron transfer (PCET) from N–H bond of the amide.
- Usami, Kaoru,Yamaguchi, Eiji,Tada, Norihiro,Itoh, Akichika
-
p. 1496 - 1504
(2019/06/27)
-
- Visible-Light-Induced Arene C(sp 2)-H Lactonization Promoted by DDQ and tert -Butyl Nitrite
-
A visible-light photocatalytic aerobic oxidative lactonization of arene C(sp 2)-H bonds proceeds in the presence of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and tert -butyl nitrite (TBN). Under the optimized conditions, a range of 2-arylbenzoic acids is converted into the corresponding benzocoumarin derivatives in moderate to excellent yields. This method is characterized by its atom economy, mild reaction conditions, the use of a green oxidant and metal-free catalysis.
- Chen, Bajin,Hu, Baoxiang,Hu, Xinquan,Jin, Liqun,Li, Meichao,Shen, Zhenlu,Sun, Nan,Wang, Shengpeng,Wang, Yiqing
-
p. 261 - 266
(2020/02/18)
-
- Facile preparation of 3,4-benzocoumarins from 2-arylbenzoic acids with NCS and NAI
-
– Treatment of 2-arylbenzoic acids with N-chlorosuccinimide (NCS) and NaI at 70 °C under fluorescent lighting condition gave the corresponding 3,4-benzocoumarins in good yields under transition-metal-free condition. It was found that the reactivity of NCS
- Nakamura, Momoko,Togo, Hideo
-
-
- Vitamin Catalysis: Direct, Photocatalytic Synthesis of Benzocoumarins via (-)-Riboflavin-Mediated Electron Transfer
-
An operationally simple protocol is disclosed to facilitate entry to benzo-3,4-coumarins directly from biaryl carboxylic acids without the need for substrate prefunctionalization. Complementary to classic lactonization strategies, this disconnection relies on the oxidation competence of photoactivated (-)-riboflavin (vitamin B2) to generate the heterocyclic core via photoinduced single electron transfer. Collectively, the inexpensive nature of the catalyst, ease of execution, and absence of external metal additives are a convincing endorsement for the incorporation of simple vitamins in contemporary catalysis.
- Morack, Tobias,Metternich, Jan B.,Gilmour, Ryan
-
p. 1316 - 1319
(2018/03/09)
-
- Oxidant-Free C(sp2)-H Functionalization/C-O Bond Formation: A Kolbe Oxidative Cyclization Process
-
An anodic oxidation/cyclization of 2-arylbenzoic acids for the synthesis of dibenzopyranones has been developed. The reaction proceeds at room temperature with no oxidant or electrolyte required and exhibits a high atom economy with H2 being th
- Zhang, Lei,Zhang, Zhenxing,Hong, Junting,Yu, Jian,Zhang, Jianning,Mo, Fanyang
-
p. 3200 - 3207
(2018/03/25)
-
- Palladium-Catalyzed, N-(2-Aminophenyl)acetamide-Assisted Ortho-Arylation of Substituted Benzamides: Application to the Synthesis of Urolithins B, M6, and M7
-
Pd-catalyzed, selective, monoarylation of ortho-C-H bonds of various benzamides with aryl/heteroaryl iodides has been realized using N-(2-aminophenyl)acetamide (APA) as a new bidentate directing group for the first time. The reaction was tolerant of a wid
- Reddy, M. Damoder,Blanton, Alexandra N.,Watkins, E. Blake
-
p. 5080 - 5095
(2017/05/24)
-
- Ruthenium(II)-catalyzed C-H functionalizations on benzoic acids with aryl, alkenyl and alkynyl halides by weak-: O -coordination
-
C-H arylations of weakly coordinating benzoic acids were achieved by versatile ruthenium(ii) catalysis with ample substrate scope. Thus, user-friendly ruthenium(ii) biscarboxylate complexes modified with tricyclohexylphosphine enabled C-H functionalizations with aryl electrophiles. The unique versatility of the ruthenium(ii) catalysis manifold was reflected by facilitating effective C-H activations with aryl, alkenyl and alkynyl halides.
- Mei, Ruhuai,Zhu, Cuiju,Ackermann, Lutz
-
supporting information
p. 13171 - 13174
(2016/11/09)
-
- Room-temperature cobalt-catalyzed arylation of aromatic acids: overriding the ortho-selectivity via the oxidative assembly of carboxylate and aryl titanate reagents using oxygen
-
A room temperature phosphine or NHC ligand-free cobalt-catalyzed arylation of (hetero)aromatic acids has been developed. It involves an oxidative cross-coupling between carboxylate and aryl titanate reagents using oxygen as an oxidant, and the arylation at the position ortho, meta and para to the carboxylic acid group could all be achieved. As application, various (hetero)aromatic acids including xenalipin, tafamidis and the key intermediate for a cardioprotective compound have been efficiently synthesized.
- Liu, Kun-Ming,Zhang, Rui,Duan, Xin-Fang
-
supporting information
p. 1593 - 1598
(2016/02/09)
-
- Silver-Catalyzed C(sp2)-H Functionalization/C-O Cyclization Reaction at Room Temperature
-
Silver-catalyzed C(sp2)-H functionalization/C-O cyclization has been developed. The scalable reaction proceeds at room temperature in an open flask. The present method exhibits good functional-group compatibility because of the mild reaction conditions. Using a AgNO3 catalyst and a (NH4)2S2O8 oxidant in CH2Cl2/H2O solvent, various lactones are obtained in good to excellent yields. A kinetic isotope effect (KIE) study indicates that the reaction may occur via a radical process.
- Dai, Jian-Jun,Xu, Wen-Tao,Wu, Ya-Dong,Zhang, Wen-Man,Gong, Ying,He, Xia-Ping,Zhang, Xin-Qing,Xu, Hua-Jian
-
p. 911 - 919
(2015/01/30)
-
- Photocatalytic Dehydrogenative Lactonization of 2-Arylbenzoic Acids
-
A metal-free dehydrogenative lactonization of 2-arylbenzoic acids at room temperature was developed. This work illustrates the first application of visible-light photoredox catalysis in the preparation of benzo-3,4-coumarins, an important structural motif in bioactive molecules. The combination of photocatalyst [Acr+-Mes] with (NH4)2S2O8 as a terminal oxidant provides an economical and environmentally benign entry to different substituted benzocoumarins. Preliminary mechanistic studies suggest that this reaction most likely occurs through a homolytic aromatic substitution pathway.
- Ramirez, Nieves P.,Bosque, Irene,Gonzalez-Gomez, Jose C.
-
p. 4550 - 4553
(2015/09/28)
-
- Electronic effects on the substitution reactions of benzhydrols and fluorenyl alcohols. Determination of mechanism and effects of antiaromaticity
-
A range of substituted benzhydrols and fluorenols were prepared and subjected to acid catalysed methanolysis. Analysis of the rates of each of these processes showed correlation with Hammett σ+ parameters as is consistent with the significant build-up of positive charge adjacent to the ring. In combination with the similarity of the electronic susceptibility of the processes, these data suggest that both reactions proceed through a unimolecular rate-determining step. This shows that the effect of fusion of the phenyl systems (and hence potentially introducing an antiaromatic carbocation intermediate) is only to slow the rate of reaction rather than change the mechanism of the process.
- George, Stephen R. D.,Elton, Timothy E.,Harper, Jason B.
-
p. 10745 - 10750
(2015/11/17)
-
- Iridium-catalyzed ortho-arylation of benzoic acids with arenediazonium salts
-
In the presence of catalytic [{IrCpCl2}2] and Ag2CO3, Li2CO3 as the base, and acetone as the solvent, benzoic acids react with arenediazonium salts to give the corresponding diaryl-2-carboxylates under mild conditions. This C-H arylation process is generally applicable to diversely substituted substrates, ranging from extremely electron-rich to electron-poor derivatives. The carboxylate directing group is widely available and can be removed tracelessly or employed for further derivatization. Orthogonality to halide-based cross-couplings is achieved by the use of diazonium salts, which can be coupled even in the presence of iodo substituents. Directing rather than removed: In the presence of catalytic [{IrCpCl2}2], benzoic acids react with arenediazonium salts to give the corresponding diaryl-2-carboxylates. If desired, the carboxylate directing group can be removed by in situ protodecarboxylation.
- Huang, Liangbin,Hackenberger, Dagmar,Goossen, Lukas J.
-
supporting information
p. 12607 - 12611
(2015/10/28)
-
- Ambient-Temperature Ortho C-H Arylation of Benzoic Acids with Aryl Iodides with Ligand-Supported Palladium Catalyst
-
The ambient-temperature ortho C-H arylation of electron-deficient benzoic acids with aryl iodides has been achieved by using an Ac-Ile-OH-supported Pd catalyst. A wide range of unactivated benzoic acids could cross-couple an array of aryl iodides in moderate to excellent yields. The choice of HFIP as a solvent is crucial to realizing the mild C-H arylation, and the beneficial effect of the ligand on the reaction likely stems from the accelerated C-H activation process and the improved catalyst lifetime.
- Zhu, Changlei,Zhang, Yuanfei,Kan, Jian,Zhao, Huaiqing,Su, Weiping
-
supporting information
p. 3418 - 3421
(2015/07/28)
-
- Synthesis of fluorenones through rhodium-catalyzed intramolecular acylation of biarylcarboxylic acids
-
An efficient approach to the synthesis of fluorenones via the rhodium-catalyzed intramolecular acylation of biarylcarboxylic acids was developed. Using this procedure, fluorenones with various substituents can be synthesized in good to high yields. This work marks the first recorded use of catalytic intramolecular acylation to synthesize fluorenones.
- Fukuyama, Takahide,Maetani, Shinji,Miyagawa, Kazusa,Ryu, Ilhyong
-
p. 3216 - 3219
(2014/07/08)
-
- Iridium-catalyzed annulative coupling of 2-arylbenzoyl chlorides with alkynes: Selective formation of phenanthrene derivatives
-
2-Arylbenzoyl chlorides undergo annulative coupling with internal alkynes in the presence of a catalyst system of [IrCl(cod)]2/P(t-Bu)3 to selectively afford the corresponding phenanthrene derivatives accompanied by elimination of carbon monoxide and hydrogen chloride. The reaction occurs without addition of any external base. Deuterium-labeling experiments using 2-(d5-phenyl)benzoyl chloride suggest that the rate-determining step does not involve the C2′-H bond cleavage. Formation of a [(t-Bu)3PH][(biphenyl-2,2′-diyl)Ir(CO)Cl2] complex dimer, of which the structure was determined by single-crystal X-ray analysis, from a stoichiometric reaction at 60 °C without addition of alkyne also supports the facile C-H cleavage.
- Nagata, Tomoya,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
-
p. 8960 - 8967
(2015/02/19)
-
- Palladium-catalyzed cross-coupling reactions of arylsiloxanes with aryl halides: Application to solid-supported organic synthesis
-
The solid-phase version of the Pd-catalyzed Hiyama reaction between a variety of aryltriethoxysilanes and immobilized aryl halides was developed. Smooth cross-coupling was achieved to afford the corresponding biaryl products in moderate to excellent yields. The described protocol would be particularly useful for the construction of 4′-substituted 1,1′-biphenyl derivatives.
- Traficante, Carla I.,Delpiccolo, Carina M. L.,Mata, Ernesto G.
-
supporting information
p. 211 - 214
(2014/06/09)
-
- General and practical carboxyl-group-directed remote C-H oxygenation reactions of arenes
-
Two methods for remote aromatic C-H oxygenation reactions, have been developed. Method1, the Cu-catalyzed oxygenation reaction, is highly efficient for cyclization of electron-neutral and electron-rich biaryl carboxylic acids into 3,4-benzocoumarins. Method2, the K2S2O 8-mediated oxygenation reaction, is more general and practical for cyclization of substrates with electron-donating and -withdrawing groups (see scheme). Copyright
- Wang, Yang,Gulevich, Anton V.,Gevorgyan, Vladimir
-
p. 15836 - 15840
(2014/04/03)
-
- 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)
-
- Palladium-catalyzed intermolecular decarboxylative coupling of 2-phenylbenzoic acids with alkynes via C-H and C-C bond activation
-
A novel protocol for palladium-catalyzed intermolecular formal [4 + 2] annulation of 2-phenylbenzoic acids with alkynes is described. Acridine is shown to be essential for the high reaction efficiency. Phenanthrene derivatives are formed in moderate to good yields without coupling (pseudo)halides or organometallic species.
- Wang, Congyang,Rakshit, Souvik,Glorius, Frank
-
supporting information; experimental part
p. 14006 - 14008
(2010/12/24)
-
- NITROGENOUS FUSED HETEROAROMATIC RING DERIVATIVE
-
The invention provides a compound or its pharmaceutically-acceptable salt of formula (I): wherein A1 is a hydrogen, etc.; j and k are 0 or 1; is a double bond, etc.; is a double bond, etc.; one of W1 and W2 is E-O-W, etc., and the other is a hydrogen atom, etc.; E is a divalent group derived from a benzene ring, etc., by removing two hydrogen atoms therefrom; W is a group of formula (II-1): which has a histamine-H3 receptor antagonistic effect or a histamine-H3 receptor inverse-agonistic effect and is useful for prevention or remedy of metabolic system diseases, circulatory system diseases or nervous system diseases.
- -
-
Page/Page column 49
(2010/11/24)
-
- Radical dearomatization of arenes and heteroarenes
-
The stannane-mediated benzeneselenol-catalyzed addition of aryl iodides to a range of arenes and aromatic hetereocycles has been studied. With furan, thiophene, and several carbocyclic arenes, the addition takes place with quenching of the adduct radical by the catalytic selenol leading to moderate yields of aryl-dihydroarenes. With nitrogen heterocycles, on the other hand, it was not possible to suppress aromatization of the adduct radical and fully aromatized products were isolated. Aryl iodides bearing hydrogen bond donating groups in the ortho-position add to nitrogen heterocycles with high selectivity ortho- to the nitrogen, affording a simple one-step synthesis of potential chelating ligands. While 2-iodophenol is an excellent aryl radical source in these reactions, the homologous 1-iodo-2-naphthol fails owing to its reaction with diphenyl diselenide, which gives 1-phenylseleno-2-naphthol in high yield.
- Crich, David,Patel, Mitesh
-
p. 7824 - 7837
(2007/10/03)
-
- An improved protocol for ligandless Suzuki-Miyaura coupling in water
-
Using a reverse order of addition of reagents, PdCl2 and Pd(OAc)2 are efficient catalysts for the Suzuki-Miyaura reactions in water. The ligandless and mild conditions, the high stability of the catalytic system, short reaction time and good to excellent yields are important features of this protocol.
- Korolev, Dmitrii N.,Bumagin, Nikolay A.
-
p. 4225 - 4229
(2007/10/03)
-
- A practical preparation of 2-carboxyphenylboronic acid and its application for the preparation of biaryl-2-carboxylic acids using Suzuki coupling reactions
-
A practical synthesis of 2-carboxyphenylboronic from 2-tolylboronic acid and aqueous potassium permanganate under mild conditions is reported. The title compound couples with aryl bromides containing electron-withdrawing groups to give biaryl-2-carboxylic
- Tao, Bin,Goel, Subhash C.,Singh, Jagvir,Boykin, David W.
-
p. 1043 - 1046
(2007/10/03)
-
- Hypervalent iodine in synthesis XL: First example of palladium-catalyzed coupling reaction of 1-hydroxy-1,2-benziodoxol-3(1H)-one with arylboronic acids and arylborates
-
Biaryl-2-carboxylic acids have been prepared by palladium-catalyzed coupling reaction of 1-hydroxy-1,2-benziodoxol-3(1H)-one with arylboronic acids and arylborates with good yields under mild conditions.
- Xia, Min,Chen, Zhenchu
-
-
- Nonpeptide arginine vasopressin antagonists for both V(1A) and V2 receptors: Synthesis and pharmacological properties of 2-Phenyl-4'- [(2,3,4,5-tetrahydro-1H-1-benzazepin-1-yl)carbonyl]benzanilide derivatives
-
A series of compounds structurally related to 4'-[(2,3,4,5-tetrahydro- 1H-1-benzazepin-1-yl)carbonyl]benzanilide was synthesized and demonstrated to have arginine vasopressin (AVP) antagonist activity for both V(1A) and V2 receptors. The introduction of a phenyl or a 4-substituted phenyl group into the ortho position of the benzoyl moiety resulted in an increase in both binding affinity and antagonistic activity. The 2-(4-methylphenyl) derivative (1g) exhibited high antagonistic activities for both V(1A) (8.6- fold) and V2 (38-fold) receptors and high oral activity (8.6-fold) compared with the 2-methyl lead compound (1a). Detail of the synthesis and the pharmacological properties of this series are presented.
- Matsuhisa, Akira,Tanaka, Akihiro,Kikuchi, Kazumi,Shimada, Yoshiaki,Yatsu, Takeyuki,Yanagisawa, Isao
-
p. 1870 - 1874
(2007/10/03)
-
- A Novel Series of Selective, Non-Peptide Inhibitors of Angiotensin II Binding to the AT2 Site
-
The availability of peptide and non-peptide Ang II receptor antagonists has permitted the study of Ang II receptor heterogeneity.It is now widely recognized that there are at least two distinct Ang II receptor subtypes.AT1 receptors are selective in their recognition of agents such as losartan, DuP 532,L-158,809,SKF108566, and similar non-peptides.To date, all of the well-known actions of Ang II in mammals are blocked by the AT1 selective antagonists such as losartan and are thus designated as being mediated by the AT1 receptor.Although there have been reports of functional activity mediated through AT2 sites, the pharmacological role for the AT2 receptor has not yet been elucidated.Herein, we report the chemistry and SAR on a novel series of 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acids which have selective affinity for AT2 receptors.The most potent of which (19) has an IC50 of 30 nM for the AT2 receptor in the rat adrenal radioligand binding assay.
- VanAtten, Mary K.,Ensinger, Carol L.,Chiu, Andrew T.,McCall, Dale E.,Nguyen, Tam T.,et al.
-
p. 3985 - 3992
(2007/10/02)
-
- Biaryl aldehyde
-
This invention relates to a method of synthesis of certain substituted carboxylic acids useful in lowering serum triglyceride and total cholesterol levels in mammals (including man) represented by the general formula I: wherein Ar1 is selected from STR1 Ar2 is selected from STR2 and R is selected from C1-5 alkyl, halogen, perhalo-C1-4 alkyl, C1-4 alkoxy, phenyl, C1-4 acyl, C1-6 alkoxycarbonyl, amino or hydroxy.
- -
-
-
- Intramolecular Cyclisations of Biphenyl-2-carboxyl Radicals: Evidence for a Π-State Aroyloxyl Radical
-
Biphenyl-2-carboxyl radicals generated by homolysis of acyl hypoiodites cyclise intramoleculary giving mainly δ-lactones through Ar2-6 cyclisation. 2'-Alkoxybiphenyl-2-carboxyl radicals do not give the expected Ar1-5 cyclisation product but undergo a homolytic ipso-substitution of the 2'-substituent.The phenanthrene-4-carboxyl radical gives 5H-phenanthropyran-5-one.Consideration of the molecular orbitals involved suggests that the biphenyl-2-carboxyl radicals are in the ?-ground state and have a higher energy, and, therefore, a less thermally accessible Σ-state than the corresponding amido-radicals.It is suggested that acyloxyl radicals which readily decarboxylate have either a Σ-ground state or a thermally accessible excited Σ-state.
- Glover, Stephen A.,Golding, Stephen L.,Goosen, Andre,McCleland, Cedric W.
-
p. 842 - 848
(2007/10/02)
-