- Investigation of the Locked-Unlocked Mechanism in Living Anionic Polymerization Realized with 1-(Tri-isopropoxymethylsilylphenyl)-1-phenylethylene
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Reported is an intriguing advance in living anionic polymerization (LAP) by a “locked-unlocked” mechanism in which the living anionic species can be quantitatively locked by end-capping with 1-(tri-isopropoxymethylsilylphenyl)-1-phenylethylene (DPE-Si(O-i
- Liu, Pibo,Ma, Hongwei,Han, Li,Shen, Heyu,Yang, Lincan,Li, Chao,Hao, Xinyu,Li, Yang
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Read Online
- Photoredox-Catalyzed α-Aminomethyl Carboxylation of Styrenes with Sodium Glycinates: Synthesis of γ-Amino Acids and γ-Lactams
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A visible-light photoredox-catalyzed reductive α-aminomethyl carboxylation of styrenes with sodium glycinates and CO2 has been developed to synthesize a series of α,α-disubstituted γ-amino acids and γ-lactams with high efficiency and regioselectivity. Notably, CO2 released from the decarboxylation step can be reused for the subsequent carboxylation. Distinct from the previous reactions with the same type of substrates leading to simple decarboxylation and olefin hydroalkylation, this process involves additional CO2 sequestration, thus leading to olefin α-aminomethyl carboxylation. These findings not only provide new access to α,α-disubstituted γ-amino acids and γ-lactams but also serve as a proof of concept for CO2 reutilization in decarboxylation reactions.
- Zhou, Cong,Li, Miao,Sun, Jianwei,Cheng, Jiang,Sun, Song
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supporting information
p. 2895 - 2899
(2021/05/05)
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- Visible-Light-Induced Meerwein Fluoroarylation of Styrenes
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An unprecedented approach for assembling a broad range of 1,2-diarylethane derivatives with fluorine-containing fully substituted carbon centers was developed. The protocol features straightforward operation, proceeds under metal-free condition, and accommodates a large variety of synthetically useful functionalities. The critical aspect to the success of this novel transformation lies in using aryldiazonium salts as both aryl radical progenitor and also as single electron acceptor which elegantly enables a radical-polar crossover manifold.
- Tang, Hai-Jun,Zhang, Bin,Xue, Fei,Feng, Chao
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supporting information
p. 4040 - 4044
(2021/05/26)
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- Iodobenzene-catalyzed oxidative cleavage of olefins to carbonyl compounds
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A metal-free approach for the oxidative cleavage of carbon–carbon double bonds of olefins to carbonyl compounds was established by using oxidant m-CPBA and non-metallic organocatalyst PhI in toluene/H2O. A broad scope of aromatic olefins was used. All the reactions proceeded smoothly at 35 °C in short reaction time to furnish the respective mono- and double carbonyl compounds selectively in moderate to good yields.
- Du, Lele,Wang, Zechao,Wu, Junliang
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- Cu/Ni-Catalyzed Cyanomethylation of Alkenes with Acetonitrile for the Synthesis of β,γ-Unsaturated Nitriles
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We have developed a protocol for the Cu/Ni-catalyzed cyanomethylation of alkenes with acetonitrile for the synthesis of β,γ-unsaturated nitriles. This is the first example of a direct coupling of the alkene sp2 C - H bond and the acetonitrile sp3 C - H bond for the preparation of β,γ-unsaturated nitriles. Acetonitrile, an inexpensive and stable solvent, is demonstrated to be a useful cyanomethyl source. The combination of copper and nickel catalysts resulted in a high reaction efficiency.
- Jian, Hong,Shen, Zengming,Zhang, Saisai
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p. 6143 - 6150
(2020/05/22)
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- Bisoxazoline-pincer ligated cobalt-catalyzed hydrogenation of alkenes
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The efficient and atom economical hydrogenation of alkenes using a novel bisoxazoline ligated cobalt complex has been developed. The hydrogenation of a variety of alkenes containing electron neutral and electron-donating groups proceeds in high yield, whi
- Ritz, Mikhaila D.,Parsons, Astrid M.,Palermo, Philip N.,Jones, William D.
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supporting information
(2020/02/13)
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- Synthesis of Trifluoromethylated Tetrasubstituted Allenes via Palladium-Catalyzed Carbene Transfer Reaction
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Herein, we report on the palladium-catalyzed synthesis of trifluoromethylated, tetrasubstituted allenes from vinyl bromides and trifluoromethylated diazoalkanes in good to excellent yield. This reaction proceeds via oxidative addition of a Pd(0) complex w
- Koenigs, Rene M.,Pei, Chao,Yang, Zhen
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supporting information
p. 7300 - 7304
(2020/10/02)
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- Bimolecular vinylation of arenes by vinyl cations
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Styrene derivatives can be easily synthesized from vinyl triflates and arenes under mild reaction conditions, using [Li][Al(OC(CF3)3)4] as a catalyst and LiHMDS as a base. This transformation is likely to involve a vinyl cation intermediate as an electrophile, which is corroborated by DFT calculations, deuterium-labeling and other control experiments. The use of an inert weakly coordinating anion is a decisive factor in this bimolecular vinylation process. This journal is
- Bour, Christophe,Gandon, Vincent,Li, Zhilong
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supporting information
p. 6507 - 6510
(2020/07/02)
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- Method for synthesizing alpha,beta-unsaturated selenium compound
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The invention belongs to the field of organic selenium chemistry, and particularly relates to a method for synthesizing an alpha,beta-unsaturated selenium compound. The compound is synthesized by using an aryl boronic acid compound, elemental selenium and a diarylethene compound as reaction substrates. The method avoids toxic selenium-mercury reagents and toxic selenide reagents, conforms to the modern green development concept, and provides a green and economical method for synthesizing unsaturated selenium compounds in the future.
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Paragraph 0062-0065
(2019/11/28)
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- THERAPEUTIC COMPOUNDS
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The present disclosure relates to compounds of formula (I): and pharmaceutically acceptable salts thereof, wherein R1-R3 have any of the values defined herein, and compositions and uses thereof. The compounds are useful as inhibitors
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Paragraph 00296
(2019/12/25)
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- A convenient access to allylic triflones with allenes and triflyl chloride in the presence of (EtO)2P(O)H
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A simple method for the preparation of allylic triflones from allenes and triflyl chloride in the presence of (EtO)2P(O)H has been developed. The features of this reaction are catalyst-free and simple starting substrates. This method tolerates diverse functional groups and substituted allylic triflones are obtained in moderate to good yields.
- Ni, Jixiang,Jiang, Yong,An, Zhenyu,Lan, Jingfeng,Yan, Rulong
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supporting information
p. 7343 - 7345
(2019/06/27)
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- Dehydrative Cross-Coupling of 1-Phenylethanol Catalysed by Palladium Nanoparticles Formed in situ under Acidic Conditions
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A dehydrative cross-coupling of 1-phenylethanol catalysed by sugar derived, in situ formed palladium(0) nanoparticles under acidic conditions is realised. The acidic conditions allow for use of alcohols as a feedstock in metal-mediated coupling reactions via their in situ dehydration and subsequent cross-coupling. Extensive analysis of the size and morphology of the palladium nanoparticles formed in situ showed that the zero-valent metal was surrounded by hydrophilic hydroxyl groups. EDX-TEM imaging studies using a prototype silicon drift detector provided insight into the problematic role of molecular oxygen in the system. This increased understanding of the catalyst deactivation allowed for the development of the cross-coupling methodology. A 250-12,000 fold increase in molar efficiency was observed when compared to related two-step protocols that use alternative feedstocks for the palladium-mediated synthesis of stilbenes. This work opens up a new research area in which the active catalyst is formed, stabilised and regenerated by a renewable sugar.
- Camp, Jason E.,Bousfield, Thomas W.,Dunsford, Jay J.,Adams, James,Britton, Joshua,Fay, Michael W.,Angelis-Dimakis, Athanasios
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supporting information
p. 3862 - 3874
(2018/09/29)
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- Regioselective Transfer Hydrodeuteration of Alkenes with a Hydrogen Deuteride Surrogate Using B(C6F5)3 Catalysis
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A regioselective hydrodeuteration of alkenes using monodeuterated cyclohexa-1,4-dienes as surrogates for hydrogen deuteride (HD) gas is reported. The metal-free process proceeds under B(C6F5)3 catalysis presumably by deuteride abstraction to form borodeuteride [DB(C6F5)3]a and highly Br?nsted-acidic Wheland intermediates. Low catalyst loadings (2.5 mol %) are used, and the reaction proceeds at room temperature.
- Walker, Johannes C. L.,Oestreich, Martin
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supporting information
p. 6411 - 6414
(2018/10/20)
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- Electrochemically Enabled Carbohydroxylation of Alkenes with H2O and Organotrifluoroborates
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Unprecedented hydroxy-alkynylation and -alkenylation reactions of arylalkenes have been developed through electrochemically enabled addition of an organotrifluoroborate reagent and H2O across the double bond of the alkene. The use of electrochemistry to promote these oxidative alkene 1,2-difunctionalization reactions not only obviates the need for transition-metal catalysts and oxidizing reagents but also ensures high regio- and chemoselectivity to afford homopropargylic or homoallylic alcohols. The possibility of extending the electrochemical alkene difunctionalization strategy to other alkene carbo-heterofunctionalization reactions has been demonstrated.
- Xiong, Peng,Long, Hao,Song, Jinshuai,Wang, Yaohui,Li, Jian-Feng,Xu, Hai-Chao
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supporting information
p. 16387 - 16391
(2018/11/23)
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- Aminosilyl-Substituted Diarylethene Compounds for Anionic Polymerisation
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The invention related to novel compounds useful as modifying monomers and precursors for polymerization initiators. The invention further relates to a method of making the polymerization initiators and resulting polymers. The invention also relates to pol
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Paragraph 0174-0182
(2017/08/07)
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- Mn(OAc)3-Mediated Synthesis of 3-Phosphonyldihydrofurans from β-Ketophosphonates and Alkenes
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A new, general method for the synthesis of 3-phosphonyldihydrofuran derivatives has been achieved through Mn(OAc)3-mediated radical cyclization between β-ketophosphonates and alkenes. This transformation allows the direct formation of C-C/C-O bonds and the construction of a dihydrofuran ring in one reaction with operational simplicity and excellent functional-group compatibility.
- Lu, Guozhang,Lin, Binzhou,Gao, Yuzhen,Ying, Jianxi,Tang, Guo,Zhao, Yufen
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p. 724 - 728
(2017/03/21)
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- Pyridine-directed asymmetric hydrogenation of 1 1-diarylalkenes
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Highly enantioselective pyridine-directed rhodium-catalyzed asymmetric hydrogenation of challenging 1 1-diarylalkenes is achieved by using [Rh(NBD)DuanPhos]BF4 as a precatalyst. Various types of 2-pyridine substituted 1 1-diarylalkenes could be hydrogenated with good to excellent enantioselectivities which provide an efficient route to the synthesis of pharmaceutically and biologically active compounds containing a 2-pyridyl ethane unit.
- Yang, Hailong,Wang, Erfei,Yang, Ping,Lv, Hui,Zhang, Xumu
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supporting information
p. 5062 - 5065
(2017/11/07)
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- Traceless directing group mediated branched selective alkenylation of unbiased arenes
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Owing to the synthetic importance of branched olefinated products, we report palladium catalyzed formation of branched olefins facilitated by a C-H activation based protocol. This involves selective insertion of olefins and subsequent decarboxylation using a completely unbiased benzene ring as the starting precursor. The significance of the protocol has been further highlighted by exhibition of functionality tolerance along with a late-stage modification of the branched olefinated products leading to the formation of other functionalized molecules.
- Agasti, Soumitra,Dey, Aniruddha,Maiti, Debabrata
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supporting information
p. 12191 - 12194
(2016/10/21)
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- Metal-free oxidative cross-coupling of diazirines with arylboronic acids
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We report herein a metal-free cross-coupling of diazirines with arylboronic acids under oxidative conditions. The reaction affords a series of substituted olefins. It is proposed that the interaction between the nitrogen on diazirine with arylboronic acid plays a key role in this transformation.
- Wu, Guojiao,Zhao, Xia,Ji, Wenzhi,Zhang, Yan,Wang, Jianbo
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p. 1961 - 1963
(2016/02/05)
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- Electrophilic Fluorophosphonium Cations in Frustrated Lewis Pair Hydrogen Activation and Catalytic Hydrogenation of Olefins
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The combination of phosphorus(V)-based Lewis acids with diaryl amines and diaryl silylamines promotes reversible activation of dihydrogen and can be further exploited in metal-free catalytic olefin hydrogenation. Combined experimental and density functional theory (DFT) studies suggest a frustrated Lewis pair type activation mechanism. FLP hydrogenation: The combination of a phosphorus(V)-based Lewis acid with diaryl amines or diaryl silylamines promotes reversible activation of dihydrogen and can be further exploited in metal-free catalytic olefin hydrogenation. Combined experimental and density functional theory (DFT) studies suggest a frustrated Lewis pair (FLP)-type activation mechanism.
- Vom Stein, Thorsten,Perz, Manuel,Dobrovetsky, Roman,Winkelhaus, Daniel,Caputo, Christopher B.,Stephan, Douglas W.
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supporting information
p. 10178 - 10182
(2015/09/01)
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- Conducting moisture sensitive reactions under mechanochemical conditions
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Dry organic solvents are used for various organic reactions that employ moisture sensitive reagents. The processes to dry these solvents are hazardous and costly. Setting up reactions in an open atmosphere while using moisture sensitive reagents has little to no effect on the rate or yield of the reaction under mechanochemical conditions. We believe this is partly due to the gaseous nature of the water vapor in the air compared to the dissolved water and oxygen in solution.
- Waddell, Daniel C.,Clark, Tammara D.,MacK, James
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body text
p. 4510 - 4513
(2012/10/07)
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- Detecting structural polydispersity in branched polybutadienes
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The structural details of a set of highly entangled H-shaped polybutadienes (PBDs) prepared by anionic polymerization were examined in detail by three reputable laboratories using size exclusion chromatography (SEC) and temperature gradient interaction chromatography (TGIC). While SEC data indicated that samples having the desired structures (i.e., nearly monodisperse H-shaped polymer) had been produced, additional SEC data from other laboratories showed that the samples were structurally more complex than originally thought. TGIC data revealed that while the samples did not contain high molecular weight byproducts, they did contain low molecular weight byproducts. To discern these structural details of the branched PBDs, small amounts of sample were fractionated by TGIC. By combining knowledge of the polymerization process with the TGIC data of fractionated samples, it was possible to work out the detailed compositions of the samples and the branching structures of each component.
- Li, Si Wan,Park, Heon E.,Dealy, John M.,Maric, Milan,Lee, Hyojoon,Im, Kyuhyun,Choi, Heungyeal,Chang, Taihyun,Rahman, M. Shahinur,Mays, Jimmy
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experimental part
p. 208 - 214
(2012/01/30)
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- 4,5-DIHYDRO-OXAZOL-2-YL AMINE DERIVATIVES
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The present invention relates to a compounds of formula I wherein R1, R1′, R2, R3, R4, X, Ar, and m are as defined in the specification and claims and pharmaceutically active acid addition salts thereof. Compounds of the invention have Asp2 (β-secretase, BACE 1 or Memapsin-2) inhibitory activity and are useful for the treatment of diseases characterized by elevated β-amyloid levels or β-amyloid deposits, particularly Alzheimer's disease.
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Page/Page column 13
(2009/09/05)
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- Synthesis of 1,1-diaryl ethylenes by Cu-catalyzed arene C-H addition to aryl acetylenes
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An unprecedented copper-catalyzed C-H addition of arenes to aryl acetylenes provides a facile route to 1,1-diaryl ethylenes in moderate to excellent yields. Arylboronic acids were likewise used along with aryl acetylenes in generating 1,1-diaryl ethylene.
- Bhilare, Sachin V.,Darvatkar, Nitin B.,Deorukhkar, Amol R.,Raut, Dilip G.,Trivedi, Girish K.,Salunkhe, Manikrao M.
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scheme or table
p. 893 - 896
(2009/05/27)
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- Synthesis of benzophenones from geminal biaryl ethenes using m-chloroperbenzoic acid
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The oxidation of geminal biaryl ethenes 3 and 1,3-enynes 5 using m-chloroperbenzoic acid in dichloromethane at room temperature presents a catalyst-free approach for the synthesis of functionalized benzophenones 4 and ynones 6, respectively.
- Singh, Fateh V.,Milagre, Humberto M.S.,Eberlin, Marcos N.,Stefani, Helio A.
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experimental part
p. 2312 - 2316
(2009/09/06)
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- Gold(I)-catalyzed oxidative cleavage of a C-C double bond in water
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Oxidative cleavage of the C=C bond to afford ketone or aldehyde products with tert-butyl hydrogenperoxide (TBHP) as the oxidant can be catalyzed by AuCl with neocuproine (1) in water.
- Xing, Dong,Guan, Bingtao,Cai, Guixin,Fang, Zhao,Yang, Liping,Shi, Zhangjie
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p. 693 - 696
(2007/10/03)
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- Preparation of prodrugs for selective drug delivery
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Synthesis of a chemical compound having the formula A-B-C that may serve for applications such as drug delivery where A is a chemiluminescent, moiety, B is a photochromic moiety, and C is a biologically active moiety where A-B-C may serve as a prodrug. No
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Page/Page column 102
(2010/02/11)
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- Mizoroki-Heck type arylation of alkenes using aroyl chlorides under base-free conditions
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The Mizoroki-Heck type arylation of alkenes with aroyl chlorides accompanied by decarbonylation efficiently proceeds in the presence of a palladium catalyst system, PdCl2(PhCN)2/(PhCH 2)Bu3NCl, even without adding any base. The products can be isolated by a very simple procedure.
- Sugihara, Toru,Satoh, Tetsuya,Miura, Masahiro
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p. 8269 - 8271
(2007/10/03)
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- Recyclable ligand-free mesoporous heterogeneous Pd catalysts for Heck coupling
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Ligand-free Pd-MCM41 catalysts are highly active in the Heck coupling of bromoarenes including deactivated bromo derivatives to give coupled products in high yields with high selectivities without the need to exclude air or moisture. The catalyst samples exhibit unprecedented stability among heterogeneous catalysts and can be reused at least 20 times to achieve complete conversion without any additional activation treatment.
- Papp, Attila,Galbács, Gábor,Molnár, árpád
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p. 7725 - 7728
(2007/10/03)
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- Charge-transfer interactions in 4-donor 4′-acceptor substituted 1,1-diphenylethenes
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Two 1,1-diphenylethenes bearing either a 4-dimethylamino or 4-methoxy group as electron donor and a 4′-cyano group as electron acceptor, as well as compounds containing only a donor or acceptor functionality, were synthesized. The observation of strong fl
- Van Walree, Cornelis A.,Kaats-Richters, Veronica E. M.,Veen, Sandra J.,Wieczorek, Birgit,Van Der Wiel, Johanna H.,Van Der Wiel, Bas C.
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p. 3046 - 3056
(2007/10/03)
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- Efficient synthesis of trisubstituted alkenes in an aqueous-organic system using a versatile and recyclable Rh/m-TPPTC catalyst
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We have found that the use of [Rh(cod)OH]2 associated with the water-soluble ligand m-TPPTC was highly efficient for the Rh-catalyzed arylation of alkynes. Aryl and alkyl alkynes were transformed to alkenes using 3mol% rhodium catalyst and 2.5equiv of boronic acid at 100°C in a biphasic water/toluene system in 80-99% yield. The reaction was found to be totally regioselective for alkyl arylalkynes and alkyl silylated alkynes. The Rh/m-TPPTC system was for the first time recycled with no loss of the activity and with excellent purity of the desired alkene.
- Genin, Emilie,Michelet, Véronique,Genêt, Jean-Pierre
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p. 4157 - 4161
(2007/10/03)
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- Preparation of 1,1-diphenylethanols by addition of organotitanium compounds to substituted aceto- and benzophenones
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The 1,1-diphenylethanols 5a-h were prepared by the addition of phenyltitanium triisopropoxide (3) to 4-substituted acetophenones 1a-h. The titanium tetraalkoxide 7, formed in situ from 3 and 1a, forms complexes with up to two molecules of 1a, this was established by 13C-NMR. Preparation of the alcohols 5a-f was also carried out by the reaction of methyltitanium triisopropoxide (4) with 4-substituted benzophenones 2a-f.
- Dimitrov,Stanchev,Milenkov,Nikiforov,Demirev
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p. 228 - 232
(2007/10/02)
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- Clathrate Formers with Allene Structure - Host Compounds, Crystal Inclusion and Structure of a Dioxane Clathrate
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The tetraaryl-substituted allenes 1-8 are synthesized, and their properties in crystal inclusion are determined.Dependent on the type and number of the substituents, host compounds result, which have different inclusion properties and clathrate selectivities.Host 1h forms inclusion compounds with a wide range of apolar and relatively polar cyclic guest solvents (26 inclusions altogether), while 2, 4, 5, and 7b form only one or two inclusions.In two-component solvent systems, high inclusion selectivities are found for the host compounds.The crystal structure of the4*dioxane (1:1) clathrate is reported.Relations between structure and inclusion selectivity are discussed.
- Weber, Edwin,Seichter, Wilhelm,Goldberg, Israel
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p. 811 - 820
(2007/10/02)
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- Reaction of Diazonium Salts with Transition Metals. Part 11. Palladium-catalyzed Aryldesilylation of Alkenylsilanes by Arenediazonium Salts
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Under palladium(0) catalysis, both (E)- and (Z)-RCH=CHSiMe3(R=Rh, 4-MeC6H4, 4-NO2C6H4, n-C6H13, and MeOCH2) were easily aryldesilylated by ArN2X(Ar=Ph, 4-MeC6H4, 4-BrC6H4 and 4-NO2C6H4; X=BF4, PF6, and Cl) to give (E)-RCH=CHAr and RC(Ar)=CH2 as the main products at 25 deg C in acetonitrile. anti- and syn-1,2-Elimination of Pd(0) and Me3Si from the adducts, threo- and erythro-RCH(PdX)CHSiMe3, generated from ArPdX and (E) and (Z)-RCH=CHSiMe3, respectively, are proposed for the formation of (E)-RCH=CHAr from either isomer of RCH=CHSiMe3.
- Ikenaga, Kazutoshi,Kikukawa, Kiyoshi,Matsuda, Tsutomu
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p. 1959 - 1964
(2007/10/02)
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- STEREOCHEMISTRY OF REACTION OF (E)- AND (Z)-Β-TRIMETHYLSILYLSTYRENE WITH ARYLPALLADIUM TETRAFLUOROBORATES GENERATED FROM ARENEDIAZONIUM TETRAFLUOROBORATES AND PALLADIUM(0)
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(E)- and (Z)-PhCH=CHSiMe3 react easily with +BF4- to give (E)-PhCH=CHAr and Ph(Ar)C=CH2 at 25 deg C.Stereochemistry of the desilylation is disclosed by using (E)- and (Z)-PhCH=CDSiMe3, that is syn-addition of Ar-Pd species followed by anti-elimination of Pd and Me3Si moiety for (E)-isomer and syn-elimination for (Z)-isomer are proposed.
- Kikukawa, Kiyoshi,Ikenaga, Kazutoshi,Wada, Fumio,Matsuda, Tsutomu
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p. 1337 - 1340
(2007/10/02)
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- ARYL REARRANGEMENT ON THE PHOTOLYSIS OF 2-ARYL-2-ETHOXY-2-PHENYLETHYL CABALOXIME.
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The photolysis of 2-aryl-2-ethoxy-2-phenylethyl cobaloxime followed by hydrolysis gave two kinds of substituted 1,2-diphenylethanones arising via phenyl or substituted-phenyl migration. The substituent effect on the aryl rearrangement is similar to that on the reported neophyl rearrangement, and the rearrangement takes place by a radical mechanism without the deep involvement of cobaloxine(II).
- Tada,Inoue,Okabe
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p. 1420 - 1423
(2007/10/02)
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