- Equivalent Loading of Directed Arenes in Pd(II)-Catalyzed Oxidative Cross-Coupling of Aryl C-H Bonds at Room Temperature
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The unsymmetrical biaryls (Ar1-Ar2) produced by the catalytic cross-couplings of aryl halides (Ar1-halo) with aryl metallics (Ar2-M) in the loading ratio of 1:1 are popular in chemical synthesis. In contrast, there has been less precedence on the same biaryls produced effectively from two normal aryl C-H bonds with equivalent loading. Here, we report that, in a palladium/oxidant/acid catalytic system at room temperature, one arene (Ar1-H, 1 equiv) can highly selectively couple with the other one (Ar2-H, 1 equiv) to afford the target Ar1-Ar2 just by controlling the directing groups and the substituted groups on their phenyl rings. The utility of this one-one cross-coupling is also demonstrated by synthesis of a few bioactive molecules.
- Mei, Chong,Zhao, Mengdi,Lu, Wenjun
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p. 2714 - 2733
(2021/02/01)
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- Visible-Light-Induced Metal-/Photocatalyst-Free C-H Bond Imidation of Arenes
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In this study, a visible-light-induced intermolecular C-H bond imidation of arenes was achieved at ambient condition. By using simple phthalimide with (diacetoxyiodo)benzene and molecular iodine, direct metal-/photocatalyst-free C-N bond formation was achieved. The imidation protocol was designed by using time-dependent density functional theory calculations and experimentally demonstrated for 28 substrates with as high as 96% yield. Mechanistic studies indicated that radical-mediated aromatic substitution occurred via photolysis of N-iodophthalimide under visible-light irradiation.
- Kuribara, Takahito,Nakajima, Masaya,Nemoto, Tetsuhiro
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supporting information
p. 2235 - 2239
(2020/03/13)
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- PPh3/I2/HCOOH: An efficient CO source for the synthesis of phthalimides
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A straightforward and general method has been developed for the synthesis of phthalimide derivatives from 2-iodobenzamides and PPh3/I2/HCOOH in the presence of a catalytic amount of Pd(OAc)2. The reaction results demonstrate that PPh3/I2/HCOOH is a facile, efficient and safe CO source. The whole process is carried out in toluene at 80 °C and furnishes the desired products in good to excellent yields.
- Wang, Yingying,Zhou, Yang,Lei, Min,Hou, Jinjun,Jin, Qinghao,Guo, Dean,Wu, Wanying
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p. 1180 - 1185
(2019/01/26)
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- Unmasking Amides: Ruthenium-Catalyzed Protodecarbonylation of N-Substituted Phthalimide Derivatives
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The unprecedented transformation of a wide range of synthetically appealing phthalimides into amides in a single-step operation has been achieved in high yields and short reaction times using a ruthenium catalyst. Mechanistic studies revealed a unique, homogeneous pathway involving five-membered ring opening and CO2 release with water being the source of protons.
- Yuan, Yu-Chao,Kamaraj, Raghu,Bruneau, Christian,Labasque, Thierry,Roisnel, Thierry,Gramage-Doria, Rafael
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supporting information
p. 6404 - 6407
(2017/12/08)
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- Efficient conversion of acids and esters to amides and transamidation of primary amides using OSU-6
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OSU-6, an MCM-41 type hexagonal mesoporous silica with strong Bronsted acid properties, has been used to promote the high-yield conversion of carboxylic acids and esters to carboxamides as well as transamidations of primary amides in a one-pot solventless approach. A metal-free heterogeneous catalyst that promotes all of these processes has not been previously reported. OSU-6 enables these transformations to proceed in shorter times and at lower temperatures for a broad range of substrates. An added benefit is that the catalyst can be recycled and reused multiple times without significant loss of activity.
- Nammalwar, Baskar,Muddala, Nagendra Prasad,Watts, Field M.,Bunce, Richard A.
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p. 9101 - 9111
(2015/11/09)
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- N -aminopyridinium salts as precursors for N-centered radicals - Direct amidation of arenes and heteroarenes
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Readily prepared N-aminopyridinium salts are valuable precursors for the generation of N-centered radicals. Reduction of these salts by single electron transfer allows for clean generation of amidyl radicals. It is shown that direct radical C-H amination of heteroarenes and arenes can be achieved with N-aminopyridinium salts under mild conditions by using photoredox catalysis.
- Greulich, Tobias W.,Daniliuc, Constantin G.,Studer, Armido
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supporting information
p. 254 - 257
(2015/03/05)
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- Synthesis and antiseizure evaluation of isoindoline-1,3-dione derivatives in mice
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Epilepsy is the most common serious chronic noninfective neurological condition in the world. Despite the presence of various antiepileptic drugs in the market for epileptic patients, the necessity for development and discovery of novel antiepileptic drugs is felt. In fact, only 60-70 % of patients respond to the current drugs, and a high incidence of adverse effects is also observed. In the present study, a new series of phthalimide derivatives (compounds 3a-3m) were synthesized through the reaction of phthalic anhydride and various derivatives of aniline in toluene solvent (Reflux, 24 h). Antiepileptic activity of synthesized compounds (3a-3m) was investigated using two experimental models namely, maximal electroshock (MES) and pentylenetetrazole (PTZ), and the obtained results were compared with diazepam as reference drug. Neurotoxicity of compounds was also evaluated using rotarod model. Compound 3m with para methoxy substituent exhibited the anticonvulsant activity at 15.1 ± 1.53 (12.23-17.96) mg/kg dose in MES model compared to other derivatives. Unfortunately, none of the tested compounds rendered acceptable protection in subcutaneous PTZ model.
- Aliabadi, Alireza,Gholamine, Babak,Karimi, Tahereh
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p. 2736 - 2743
(2014/05/06)
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- Nitrogen-centered radical-mediated C-H imidation of arenes and heteroarenes via visible light induced photocatalysis
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The C-H imidation of arenes and heteroarenes has been achieved via visible light induced photocatalysis. In the presence of an iridium(iii) photoredox catalyst, the reaction of aromatic substrates with N-chlorophthalimide furnishes the N-aryl products at room temperature through a nitrogen-centered radical mediated aromatic substitution.
- Kim, Hyejin,Kim, Taehoon,Lee, Dong Gil,Roh, Sang Weon,Lee, Chulbom
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supporting information
p. 9273 - 9276
(2014/08/05)
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- N-acyloxyphthalimides as nitrogen radical precursors in the visible light photocatalyzed room temperature C-H amination of arenes and heteroarenes
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This paper reports a room temperature visible light photocatalyzed method for the C-H amination of arenes and heteroarenes. A key enabling advance in this work is the design of N-acyloxyphthalimides as precursors to nitrogen-based radical intermediates for these transformations. A broad substrate scope is presented, including the selective meta-amination of pyridine derivatives. A radical aromatic substitution mechanism is proposed.
- Allen, Laura J.,Cabrera, Pablo J.,Lee, Melissa,Sanford, Melanie S.
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supporting information
p. 5607 - 5610
(2014/05/06)
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- Sterically controlled, palladium-catalyzed intermolecular amination of arenes
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We report the Pd-catalyzed amination of arenes to form N-aryl phthalimides with regioselectivity controlled predominantly by steric effects. Mono-, di-, and trisubstituted arenes lacking a directing group undergo amination reactions with moderate to high yields and high regioselectivities from sequential addition of PhI(OAc)2 as an oxidant in the presence of Pd(OAc) 2 as catalyst. This sterically derived selectivity contrasts that for analogous arene acetoxylation.
- Shrestha, Ruja,Mukherjee, Paramita,Tan, Yichen,Litman, Zachary C.,Hartwig, John F.
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supporting information
p. 8480 - 8483
(2013/07/19)
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- New reaction of ethenetetracarbonitrile with N-arylisoindolines
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N-Arylisoindolines 1a-i react with ethenetetracarbonitrile 2 in aerated benzene by formation of [3-(2-aryl-3-dicyanomethylene-2,3-dihydro-1H-isoindol-1-ylidene)-2-aryl-2, 3-dihydro-1H-isoindol-1-ylidene]propanedinitriles 8a-i (20-36%), N-aryl-3-dicyanomethylene-isoindol-2-ones 9a-i (15-21%) and N-arylphthalimides 10a-i (4-9%) as well as 1,1,2,2-tetracyanoethane 11 (35-55%). The structure of 8d has been unambiguously confirmed by a single crystal X-ray structure analysis. A rationale for the formation of products 8-11 is presented.
- D?pp, Dietrich,Hassan, Alaa A.,Mourad, Aboul-Fetouh E.,Nour El-Din, Ahmed M.,Angermund, Klaus,Krüger, Carl,Lehmann, Christian W.,Rust, J?rg
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p. 5073 - 5081
(2007/10/03)
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- The cyclisation of substituted phthalanilic acids in acetic acid solution. A kinetic study of substituted N-phenylphthalimide formation
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One novel and ten known substituted 3′- and 4′-phthalanilic acids have been prepared. These have been cyclised to two novel and nine known substituted N-phenylphthalimides by heating with glacial acetic acid. Both phthalanilic acids and imides have been characterised in detail and spectroscopic data are given. The kinetics of cyclisation for phthalanilic acids has been examined in detail, and it has emerged that a complex mechanism is operating. This initially involves a reversible, solvent assisted intramolecular nucleophilic attack by amide nitrogen on the carboxylic acid carbonyl. Clear evidence is seen for a long-lived intermediate as a precursor to imide formation. The observed kinetics are rationalised using a model of rapid pre-equilibration, followed by the slow breakdown of the intermediate to imide. Observed rate constants for pre-equilibration show a well behaved, linear Hammett plot (ρ = -1.1), whereas those for formation of imide do not.
- Perry, Christopher J.,Parveen, Zahida
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p. 512 - 521
(2007/10/03)
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- Chemical and electrochemical reduction of the products from the reactions of isoindolines and tetracyanoethylene
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The reduction potentials of compounds resulting from the title reaction and containing one (4) or two (3) dicyanovinylidene moieties have been determined by means of cyclic voltammetry. Electrochemical reduction of the same compounds within the cavity of an EPR spectrometer led to the observation of radical species tentatively identified as the corresponding radical anions. EPR experiemnts have also provided indication that the first formed species in the butoxide reduction of 3 undergoes cleavage of the bond between the two heterocyclic systems evolving to radical anions identical to those obtained by similar reduction of compounds 4. Some models compounds have also been investigated for comparison purposes.
- Carloni,Carloni, Patricia,Greci,Greci, Lucedio,Stipa,Stipa, Pierluigi,Dopp,Doepp, Dietrich,El-Din Abdel Hafeez Hassan,Hassan, Alaa El-Din Abdel Hafeez,Alberti,Alberti, Angelo
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p. 7451 - 7458
(2007/10/02)
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- Electrophilic amination. Direct primary amination of arenes using phthalimide derivatives
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Electrophi1ic primary amination of arenes has been achieved by the thermolysis or photolysis of N-sulfonyloxyphthalimide in the presence of trifluoromethane-sulfonic acid or of 1-phthalimido-2,4,6-triphenylpyridinium tetrafluoroborate in the presence of CF3CO2H. The diacylnitrenium 10 was probably formed in the latter case. The structure of one of the byproducts, 7 was established by single crystal X-ray analysis.
- Abramovitch, Rudolph A.,Beckert, Joseph M.,Chinnasamy, Pennamuthiriar,Xiaohua, He,Pennington, William,Sanjivamurthy, A.R.Vinutha
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p. 623 - 628
(2007/10/02)
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