Pd-Catalyzed Domino Reactions Involving Alkenes To Access Substituted Indole Derivatives
Conclusions [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - May 26, 2020 Category: Chemistry Authors: Christodoulou, Michael S. Beccalli, Egle M. Foschi, Francesca Giofr è, Sabrina Tags: review Source Type: research

Zinc(II)-Catalyzed Synthesis of Secondary Amides from Ketones via Beckmann Rearrangement Using Hydroxylamine-O-sulfonic Acid in Aqueous Media
Synthesis DOI: 10.1055/s-0040-1707809 A zinc(II)-catalyzed single-step protocol for the Beckmann rearrangement using hydroxylamine-O-sulfonic acid (HOSA) as the nitrogen source in water was developed. This direct method efficiently produces secondary amides under open atmosphere in a pure form after basic aqueous workup. It is environmentally benign and operationally simple. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - May 25, 2020 Category: Chemistry Authors: Verma, Saumya Kumar, Puneet Khatana, Anil K. Chandra, Dinesh Yadav, Ajay K. Tiwari, Bhoopendra Jat, Jawahar L. Tags: special topic Source Type: research

Recent Developments in C –C Bond Formation Using Catalytic Reductive Coupling Strategies
Conclusion and Outlook [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - May 25, 2020 Category: Chemistry Authors: Agrawal, Toolika Sieber, Joshua D. Tags: short review Source Type: research

A Convenient, Scalable Process for the Preparation and Purification of Calcium Acamprosate
Synthesis DOI: 10.1055/s-0040-1707399 Calcium acamprosate (Campral, N-acetylhomotaurine calcium salt) is a well-established drug for the treatment of alcohol dependence. Its preparation is generally based on a three-step process with some remarkable drawbacks. To avoid these flaws, we have developed a direct, scalable, one-pot procedure for the preparation of calcium acamprosate entailing the nucleophilic opening of readily available 1,3-propanesultone with potassium acetamide (from acetamide and potassium tert-butoxide) in N,N-dimethylformamide solution, followed by in situ cation exchange by addition of calcium chloride ...
Source: Synthesis - May 25, 2020 Category: Chemistry Authors: Cavarischia, Claudia Comely, Alex Écija, Marta Iacoangeli, Tommaso Past ó, Mireia Silvestri, Lavinia Furlotti, Guido Tags: psp Source Type: research

Krapcho Dealkoxycarbonylation Strategy of Ethyl Cyanoacetate for the Synthesis of 3-Hydroxy-3-cyanomethyl-2-oxindoles and 3,3 ′-Dicyanomethyl-2-oxindoles in a Reaction with Isatin
Synthesis DOI: 10.1055/s-0040-1707816 A new strategy for the synthesis of 3-hydroxy-3-cyanomethyl-2-oxindoles and 3,3′-dicyanomethyl-2-oxindoles in a reaction of isatin with ethyl cyanoacetate by Krapcho dealkoxycarbonylation reaction in aqueous media is demonstrated. The reaction provides an easy access to synthetically and medicinally valuable oxindole alkylnitriles in good to very good yields. Wider substrate scope and operationally simple experimental procedures are highlighted features of the developed protocol. Based on control experiments, a plausible mechanism of reaction and synergistic effect of water is al...
Source: Synthesis - May 25, 2020 Category: Chemistry Authors: R., Chandran Tiwari, Keshri Nath Tags: paper Source Type: research

Synthesis and Structure of 1-Substituted Semithioglycolurils
Synthesis DOI: 10.1055/s-0040-1707391 Two methods for the synthesis of previously unavailable 1-substituted semithioglycolurils were developed. These methods consist of the cyclocondensation of 1-substituted ureas with 4,5-dihydroxy- or 4,5-dimethoxyimidazolidine-2-thione or glyoxal, followed by the reaction of the resulting 1-substituted 4,5-dihydroxyimidazolidine-2-ones with HSCN in a two-step one-pot procedure. Two of the desired semithioglycolurils were obtained as conglomerates. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstr...
Source: Synthesis - May 25, 2020 Category: Chemistry Authors: Baranov, Vladimir V. Galochkin, Anton A. Nelyubina, Yulia V. Kravchenko, Angelina N. Makhova, Nina N. Tags: paper Source Type: research

Synthesis, Photophysical and Supramolecular Properties of a π-Conjugated Molecular Crown Containing a Pentagonal Unit: A Model Compound for Fullerene C240
Synthesis DOI: 10.1055/s-0040-1707963 The total synthesis of carbon onions is a significant challenge in the fields of materials science and organic chemistry. To date, the synthesis of even a fragment of fullerene C240 and its smallest carbon onion C60@C240 remains poorly explored. Herein, we demonstrate a bottom-up strategy to produce a novel π-extended molecular crown-shaped molecule (MC3) containing curved pentagonal and hexagonal units. This molecular crown represents a curved model compound for fullerene C240 and is fully characterized by NMR, mass spectrometry, UV-vis absorption, and from its emission spectra. It...
Source: Synthesis - May 20, 2020 Category: Chemistry Authors: Huang, Qiang Wu, Yayu Zhou, Yu Liu, Huiqing Wang, Jinyi Wang, Shengda Du, Pingwu Tags: paper Source Type: research

Efficient Heterogeneous Palladium-Catalyzed Transfer Hydrogenolysis of Benzylic Alcohols by Formic Acid
Synthesis DOI: 10.1055/s-0040-1707398 An efficient heterogeneous palladium-catalyzed transfer hydrogenolysis­ of primary, secondary, and tertiary benzylic alcohols using formic acid as hydrogen source has been developed. The resulting hydrocarbon products were obtained in excellent yields. Moreover, the system exhibits high chemoselectivity, reacting only with the hydroxy groups in the presence of other functional groups, and excellent re­cyclability. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  | &nb...
Source: Synthesis - May 20, 2020 Category: Chemistry Authors: Afewerki, Samson Palo-Nieto, Carlos C órdova, Armando Tags: feature Source Type: research

Recent Advances on Copper-Catalyzed C –C Bond Formation via C–H Functionalization
Conclusion and Perspective [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - May 19, 2020 Category: Chemistry Authors: Almasalma, Ahmad A. Mej ía, Esteban Tags: short review Source Type: research

Step-Economical C –H Activation Reactions Directed by In Situ Amidation
Conclusion [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - May 18, 2020 Category: Chemistry Authors: Zhao, Baoli Liu, Yunyun Tags: short review Source Type: research

Synthesis of Oxazoline and Oxazole Derivatives by Hypervalent-Iodine-Mediated Oxidative Cycloaddition Reactions
Conclusion [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - May 18, 2020 Category: Chemistry Authors: Yoshimura, Akira Saito, Akio Yusubov, Mekhman S. Zhdankin, Viktor V. Tags: short review Source Type: research

Tertiary Enamides as Versatile and Valuable Substrates to Reach Chemical Diversity
Conclusion and Perspectives [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - May 18, 2020 Category: Chemistry Authors: Beltran, Fr édéric Miesch, Laurence Tags: short review Source Type: research

Synthesis of (2S,3R,5R)-2-Azido-3,5-dihydroxynonadecane Sphingolipid Analogue
Synthesis DOI: 10.1055/s-0040-1707397 A concise and highly efficient synthesis of an enigmol analogue has been achieved. The synthetic strategy features Jacobsen’s hydrolytic kinetic resolution (HKR) and epoxide opening by alkynyl boranes as the key steps. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - May 18, 2020 Category: Chemistry Authors: Pemha, Ren é Pegnyemb, Dieudonn é Emmanuel Mosset, Paul Tags: paper Source Type: research

Sulfite-Promoted C –H Fluoroalkyl Sulfuration of Imidazoheterocycles with Bromofluoroacetate and Elemental Sulfur
Synthesis DOI: 10.1055/s-0040-1707120 A transition-metal-free sulfite-promoted three-component C–H sulfuration between imidazoheterocycles, elemental sulfur, and bromofluoroacetate is developed. Sulfites, including Na2S2O4, NaHSO3, and Na2S2O3, are able to promote the formation of two C–S bonds in one step using elemental sulfur as a green sulfurating agent, allowing the rapid introduction of the synthetically useful S-fluoroacetate group into imidazoheterocycles. These new imidazoheterocycle derivatives bearing an S-fluoroacetate group can be easily modified to produce pharmaceutically attractive compounds. [....
Source: Synthesis - May 18, 2020 Category: Chemistry Authors: Gao, Yong-Chao Huang, Zi-Hao Zhang, Zhao-Sheng Xie, Jin-Xin Cui, Zi-Ning Tang, Ri-Yuan Tags: paper Source Type: research

Non-Classical Amide Bond Formation: Transamidation and Amidation of Activated Amides and Esters by Selective N –C/O–C Cleavage
Conclusions and Outlook [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - May 15, 2020 Category: Chemistry Authors: Li, Guangchen Szostak, Michal Tags: review Source Type: research

Recent Advances in Triarylmethane Synthesis
Conclusions [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - May 14, 2020 Category: Chemistry Authors: Liu, Xue Wu, Xiangmei Zhang, Ling Lin, Xiaoyan Huang, Dayun Tags: short review Source Type: research

Electrochemical Synthesis of Sulfinic Esters via Aerobic Oxidative Esterification of Thiophenols with Alcohols
Synthesis DOI: 10.1055/s-0040-1707966 A method for the electrochemical synthesis of sulfinic esters by aerobic oxidative coupling of thiophenols and alcohols has been developed. Using electrons as the redox reagent and O2 in air as the oxygen source, the reactions proceeded smoothly at room temperature, even for a gram-scale preparation. No use of catalyst, clean redox reagent, green and abundant oxygen source, and mild reaction conditions make this strategy eco-friendly. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract &nb...
Source: Synthesis - May 14, 2020 Category: Chemistry Authors: Zhou, Hongyan Duan, Jiaokui Xie, Dongtai Yang, Jingya Ma, Ben Wang, Ganggang Wu, Chengqi Wang, Xi-Cun Tags: paper Source Type: research

Chlorination of Conjugated Nitroalkenes with PhICl2 and SO2Cl2 for the Synthesis of α-Chloronitroalkenes
Synthesis DOI: 10.1055/s-0040-1707396 Chlorination of conjugated nitroalkenes with iodobenzene dichloride or sulfuryl chloride to give target α-chloronitroalkenes in good yields is described. Details of the procedure depend on the donating ability of the nitroalkene substituents. The activity of the described chlorinating agents increases in order ‘PhICl2/Py’
Source: Synthesis - May 14, 2020 Category: Chemistry Authors: Fadeeva, Anastasia A. Ioffe, Sema L. Tabolin, Andrey A. Tags: paper Source Type: research

Synthetic Approaches to Acyl Hydrazides and Their Use as Synthons in Organic Synthesis
Conclusion [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - May 13, 2020 Category: Chemistry Authors: Spiliopoulou, Nikoleta Constantinou, Constantinos T. Triandafillidi, Ierasia Kokotos, Christoforos G. Tags: special topic Source Type: research

Application of α-Amino-β-fluorophosphonates in Construction of their Dipeptide Analogues
Synthesis DOI: 10.1055/s-0040-1707813 Herein, we present application of α-amino-β-fluorophosphonates for the construction of their dipeptide analogues. α-Amino-β-fluorophosphonates were prepared in a XtalFluor-E mediated deoxyfluorination of α-hydroxy-β-aminophosphonates. The reaction proceeds through an aziridinium ion formation, which was confirmed by the formation­ of a hexacoordinate phosphorus compound. Moreover, the absolute configuration of the obtained compounds was determined by X-ray analysis, which proved the stereochemistry. [...] © Georg Thieme Verlag Stuttgart &m...
Source: Synthesis - May 13, 2020 Category: Chemistry Authors: Ka źmierczak, Marcin Dutkiewicz, Grzegorz Cytlak, Tomasz Tags: paper Source Type: research

Synform issue 2020/6
Synthesis 2020; 52: A80-A91 DOI: 10.1055/s-0039-1691181 © Georg Thieme Verlag KG Stuttgart · New YorkArticle in Thieme eJournals: Table of contents (Source: Synthesis)
Source: Synthesis - May 13, 2020 Category: Chemistry Authors: Zanda, Matteo Tags: Synform Source Type: research

Linked PDF of Table of Contents
Synthesis 2020; 52: V- DOI: 10.1055/s-0040-1707401 © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents (Source: Synthesis)
Source: Synthesis - May 13, 2020 Category: Chemistry Tags: table of contents Source Type: research

Gold-Catalyzed Partial Hydrogenation of Activated Alkynes Mediated by Triphenylphosphine
Synthesis DOI: 10.1055/s-0040-1707395 Gold(I) can exhibit a cooperative effect with triphenylphosphine, accelerating the triphenylphosphine-mediated partial hydrogenation of activated alkynes. In this protocol, 3-arylpropiolates are selectively reduced to the Z-isomer when the aryl ring bears an electron-donor substituent, whereas 3-arylpropynones are reduced to the E-isomers. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - May 12, 2020 Category: Chemistry Authors: Cocoletzi-Xochitiotzi, Ana Patricia Hern ández-Hernández, Miguel Medina-Mercado, Ignacio Jim énez-Martínez, Williams de Jesús Mastranzo, Virginia Maricela Porcel, Susana Tags: paper Source Type: research

Regioselective Synthesis of Pyrazolyl-pyrimidine Hybrids of Pharmacological Interest
Synthesis DOI: 10.1055/s-0040-1707948 The regioselective synthesis of twenty novel [3-substituted 5-hydroxy-5-(trifluoromethyl)-4,5-dihydro-1H-pyrazol-1-yl][6-aryl-(2-methylthio)pyrimidin-4-yl]methanones from the cyclocondensation reactions of new 6-aryl-2-(methylthio)pyrimidine-4-carbohydrazides with 4-substituted 1,1,1-trifluorobut-3-en-2-ones is reported. Human acetylcholinesterase (HsAChE) and butyrylcholinesterase (HsBChE) inhibition tests were performed on selected products in order to explore the possible pharmacological applications of these compounds. Two compounds showed significant and selective inhibitory activ...
Source: Synthesis - May 12, 2020 Category: Chemistry Authors: Camargo, Adriano F. Marangoni, M ário A. de Moraes, Paulo A. Nogara, Pablo A. Afolabi, Blessing A. Bencke, Carlos E. Rocha, Jo ão B. T. Bonacorso, Helio G. Martins, Marcos A. P. Zanatta, Nilo Tags: paper Source Type: research

A Bond-Weakening Borinate Catalyst that Improves the Scope of the Photoredox α-C–H Alkylation of Alcohols
Synthesis DOI: 10.1055/s-0040-1707114 The development of catalyst-controlled, site-selective C(sp3)–H functionalization reactions is currently a major challenge in organic synthesis. In this paper, a novel bond-weakening catalyst that recognizes the hydroxy group of alcohols through formation of a borate is described. An electron-deficient borinic acid–ethanolamine complex enhances the chemical yield of the α-C–H alkylation of alcohols when used in conjunction with a photoredox catalyst and a hydrogen atom transfer catalyst under irradiation with visible light. This ternary hybrid catalyst system ca...
Source: Synthesis - May 12, 2020 Category: Chemistry Authors: Sakai, Kentaro Oisaki, Kounosuke Kanai, Motomu Tags: feature Source Type: research

Divergent Synthesis of Five-Membered Nitrogen Heterocycles via Cascade Reactions of 4-Arylfuroxans
Synthesis DOI: 10.1055/s-0040-1707393 A novel method for the synthesis of a diverse series of functionally substituted five-membered heterocyclic compounds via atom-economic, regio-, and diastereoselective one-pot reaction cascade was developed. This approach involves a ring opening in 4-arylfuroxans to α-oximinoarylacetonitrile oxides followed by [3+2] cycloaddition to various dipolarophiles to afford multisubstituted isoxazoles and isoxazolines. Subsequent azole–azole rearrangement of (oximino)isoxazolines/-isoxazoles, which can be conducted in a one-pot manner, results into functionally substituted furazans ...
Source: Synthesis - May 5, 2020 Category: Chemistry Authors: Chaplygin, Daniil A. Ananyev, Ivan V. Fershtat, Leonid L. Makhova, Nina N. Tags: paper Source Type: research

Linked PDF of Table of Contents
Synthesis 2020; 52: V- DOI: 10.1055/s-0040-1707392 © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents (Source: Synthesis)
Source: Synthesis - May 4, 2020 Category: Chemistry Tags: table of contents Source Type: research

Facile One-Pot Access to α-Diazo-β-ketosulfones from Sulfonyl Chlorides and α-Haloketones
Synthesis DOI: 10.1055/s-0040-1707525 A convenient one-pot approach to the preparation of α-diazo-β-ketosulfones from sulfonyl chlorides is described. It involves the conversion of the sulfonyl chloride to sodium sulfinate, alkylation of the latter with α-haloketones followed by diazo transfer using the ‘sulfonyl-azide-free’ (‘SAFE’) protocol in aqueous medium. The simple and expedient method relies on readily available starting materials and provides facile access to a wide variety of valuable diazo reagents for organic synthesis. [...] © Georg Thieme Verlag Stuttgart &mi...
Source: Synthesis - April 28, 2020 Category: Chemistry Authors: Dar ’in, Dmitry Kantin, Grigory Bakulina, Olga Krasavin, Mikhail Tags: paper Source Type: research

Allyl 4-Chlorophenyl Sulfone as a Versatile 1,1-Synthon for Sequential α-Alkylation/Cobalt-Catalyzed Allylic Substitution
Synthesis DOI: 10.1055/s-0040-1707524 Despite their unique potential as rare 1,1-dipole synthons, allyl sulfones are rarely used in target-oriented syntheses, likely due to the lack of a general catalytic method for their branch-selective allylic substitution. Herein, we identified allyl 4-chlorophenyl sulfone as a versatile linchpin for both base-mediated α-derivatization and subsequent cobalt-catalyzed allylic substitution. The sequential transformations allow for highly regioselective access to branched allylic substitution products with a variety of aliphatic side chains. The photoredox-enabled­ ­cobalt c...
Source: Synthesis - April 27, 2020 Category: Chemistry Authors: Sekino, Tomoyuki Sato, Shunta Kuwabara, Kazuki Takizawa, Koji Yoshino, Tatsuhiko Kojima, Masahiro Matsunaga, Shigeki Tags: paper Source Type: research

A Straightforward Synthesis of N-Substituted Ureas from Primary Amides
Synthesis DOI: 10.1055/s-0040-1707103 A direct and convenient method for the preparation of N-substituted ureas is achieved by treating primary amides with phenyliodine diacetate (PIDA) in the presence of an ammonia source (NH3 or ammonium carbamate) in MeOH. The use of 2,2,2-trifluoroethanol (TFE) as the solvent increases the electrophilicity of the hypervalent iodine species and allows the synthesis of electron-poor carboxamides. This transformation involves a nucleophilic addition of ammonia on the isocyanate intermediate generated in situ by a Hofmann rearrangement of the starting amide. [...] © Georg Thieme ...
Source: Synthesis - April 27, 2020 Category: Chemistry Authors: Saraiva Rosa, Nathalie Glachet, Thomas Ibert, Quentin Lohier, Jean-Fran çois Franck, Xavier Reboul, Vincent Tags: paper Source Type: research

Transition-Metal-Free, Intermolecular Azidoheteroarylation of Alkenes: Efficient Access to β-Azidoalkylated Quinoxalinones and Preliminary Antifungal Evaluation Against Magnaporthe grisea
Synthesis DOI: 10.1055/s-0040-1707514 An efficient, PhI(OAc)2-mediated, radical azidoheteroarylation of alkenes under transition-metal-free conditions is reported by employing TMSN3 and quinoxalin-2(1H)-ones as coupling partners. This domino reaction allows an efficient synthesis of valuable orangoazides containing quinoxalin-2(1H)-one derivatives and could be extended to phosphinyl-alkylated quinoxalin-2(1H)-one in a single step in moderate to excellent yields under mild conditions, as demonstrated by the preliminary antibacterial evaluation against Magnaporthe grisea for the first time. Mechanistic studies revealed that ...
Source: Synthesis - April 27, 2020 Category: Chemistry Authors: Du, Yiming Chen, Yue Liu, Yun-Lin Qin, Weiwei Li, Zhaodong Tags: paper Source Type: research

Catalyst- and Solvent-Free Hydrophosphorylation of Ketones with Secondary Phosphine Oxides: Green Synthesis of Tertiary α-Hydroxyphosphine Oxides
Synthesis DOI: 10.1055/s-0040-1707945 Tertiary α-hydroxyphosphine oxides have been synthesized via the catalyst- and solvent-free reaction between available secondary phosphine oxides and aliphatic, aromatic and heteroaromatic ketones at 20–62 °C in near to 96–98% yield. The developed method meets the requirements of green chemistry and the PASE (pot, atom, step economy) paradigm. According to quantum-chemical calculations at the B3LYP/6-311++G(d,p) level, the synthesized hydroxyphosphine oxides feature a weak (≈3 kcal·mol–1) O−H···O=P intramolecular ...
Source: Synthesis - April 22, 2020 Category: Chemistry Authors: Gusarova, Nina K. Ivanova, Nina I. Khrapova, Kseniya O. Volkov, Pavel A. Telezhkin, Anton A. Larina, Lyudmila I. Afonin, Andrei V. Pavlov, Dmitry V. Trofimov, Boris A. Tags: paper Source Type: research

BF3 ·OEt2-Catalyzed Aldol Condensation of Steroid Sapogenins and 2-Oxoacids: A Single Step Conversion of Steroid Spiroketals into Branched α,β-Unsaturated Spirolactones
Synthesis DOI: 10.1055/s-0040-1708018 BF3·OEt2-catalyzed aldol reaction of steroid sapogenins with glyoxylic acid or pyruvic acid led to compounds in which the novel spirocyclic side chain bears an α,β-unsaturated lactone. The structures of the new spirolactones were established with the aid of combined 1D and 2D NMR techniques. A plausible mechanism is described. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - April 21, 2020 Category: Chemistry Authors: Hern ández-Martínez, Juan E. Iglesias-Arteaga, Martin A. Tags: paper Source Type: research

Manifestation of the β-Silicon Effect in the Reactions of Unsaturated Systems Involving a 1,2-Silyl Shift
Conclusions [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - April 20, 2020 Category: Chemistry Authors: Be ļaunieks, Rūdolfs Puri ņš, Mikus Turks, M āris Tags: short review Source Type: research

An Unusual Triazole Synthesis from Aurones
Synthesis DOI: 10.1055/s-0040-1708019 Attempts to prepare azido-substituted aurones via a copper-catalyzed azidation failed to afford the desired product, but instead resulted in an unusual triazole formation reaction. Further efforts noted that copper was not required for this reaction, but simply thermal treatment with sodium azide in a polar aprotic solvent. A wide range of substitution patterns were tolerated in this reaction to afford the interesting salicyl-substituted triazoles in modest to excellent yield. While the mechanism is not yet clear, a simple elimination/cyclization pathway seems unlikely given the failur...
Source: Synthesis - April 20, 2020 Category: Chemistry Authors: Kafle, Arjun Bhattarai, Shrijiana Handy, Scott T. Tags: paper Source Type: research

Further Development of the Tin-Catalyzed Transcarbamoylation Reaction
Synthesis DOI: 10.1055/s-0040-1708020 Studies carried out to further develop tin-catalyzed trans­carbamoylation reactions demonstrated that transcarbamoylation of cinnamyl alcohol in the context of allyl cyanate-to-isocyanate rearrangement can be efficiently carried out on a ten-gram scale and that tin-­catalyzed transcarbamoylation is a valuable alternative to the method using trichloroacetyl isocyanate. In addition, methyl carbamate was found to be an economical carabamoyl donor in tin-catalyzed transcarbamoylation, which showed broad functional group tolerance and allowed a streamlined workup procedure. Finally,...
Source: Synthesis - April 20, 2020 Category: Chemistry Authors: Ichikawa, Yoshiyasu Hasegawa, Tomoyuki Minami, Takahiro Sato, Hiroshi Morishita, Yukinori Ochi, Rika Masuda, Toshiya Tags: paper Source Type: research

Zeolites Catalyze the Nazarov Reaction and the tert-Butylation of Alcohols by Stabilization of Carboxonium Intermediates
Synthesis DOI: 10.1055/s-0039-1690896 Zeolites are the most used catalysts worldwide in petrochemistry processes, with particular ability to stabilize carbocations. However, the use of zeolites in organic synthesis is still scarce. We show here that representative carboxonium-mediated organic reactions, such as the Nazarov cyclization and the tert-butylation of alcohols with tert-butyl acetate, typically performed with very strong acid catalysts in solution such as triflic acid, can be catalyzed by simple zeolites with high yield and selectivity. The aluminosilicate framework stabilizes the intermediate carboxonium species...
Source: Synthesis - April 20, 2020 Category: Chemistry Authors: Tejeda-Serrano, Mar ía Sanz-Navarro, Sergio Blake, Finn Leyva-P érez, Antonio Tags: feature Source Type: research

Reductive Amination of Aryl Boronic Acids: Parallelism of the Catalytic Reactivity of Transition Metals and Main Group Elements in the C(sp2) –N Bond-Forming Reactions
Synthesis DOI: 10.1055/s-0039-1690893 The results of the DFT studies on the mechanism of the PIII/PV=O catalyzed reductive amination of nitrosoarenes using ArB(OH)2 yielding diaryl amines are reported. This allowed a comparison of the reaction paths and key intermediates of the Cu(I)- and P(III)-mediated reductive aminations of aryl boronic acids using alkylnitrites, nitroso- or nitroarenes, and revealed important similarities in the catalytic reactivity of transition-metal and main-group elements in C(sp2)–N bond-forming reactions. It is shown that both transformations occur via ambiphilic nitrenoid-type key interme...
Source: Synthesis - April 20, 2020 Category: Chemistry Authors: Levitskiy, Oleg A. Magdesieva, Tatiana V. Tags: feature Source Type: research

Synform issue 2020/5
Synthesis 2020; 52: A66-A79 DOI: 10.1055/s-0039-1691175 © Georg Thieme Verlag KG Stuttgart · New YorkArticle in Thieme eJournals: Table of contents (Source: Synthesis)
Source: Synthesis - April 20, 2020 Category: Chemistry Authors: Zanda, Matteo Tags: Synform Source Type: research

Three-Component Reaction of Homophthalic Anhydride with Carbonyl Compounds and Ammonium Acetate: New Developments
Synthesis DOI: 10.1055/s-0040-1708017 The earlier described reaction of homophthalic anhydrides with aromatic ketones and ammonium acetate was tested for cyclic ketones (yielding spirocyclic motifs) and aliphatic aldehydes. In contrast to previous findings, the reaction was found to require no catalyst at all and to be applicable, in the non-catalyzed format, to these new carbonyl substrates as well as aromatic ketones. The reaction typically proceeds with high diastereoselectivity; if not, the initial diastereomeric mixture can be quantitatively equilibrated into a single, trans-diastereomer on treatment with aqueous base...
Source: Synthesis - April 16, 2020 Category: Chemistry Authors: Safrygin, Alexander Bakulina, Olga Dar ’in, Dmitry Krasavin, Mikhail Tags: paper Source Type: research

Direct Synthesis of 5-Acyl-3-oxy-4-pyrones Based On Acid- ­Catalyzed Acylation of Enaminodiones with Acylbenzotriazoles via Soft Enolization
Synthesis DOI: 10.1055/s-0040-1707471 A novel convenient acid-catalyzed acylation of enaminodiones with acylbenzotriazoles via soft enolization has been developed for the direct synthesis of hard-to-reach 5-acyl-3-oxy-4-pyrones. The important advantages of the reaction include broad substrate scope, mild conditions, scalability, and readily isolation of products by crystallization without the use of chromatography. Further modification of the pyrone ring and synthesis of various azaheterocycles via ring-opening transformation have been demonstrated for the preparation of potential scaffolds for inhibition of metalloenzymes...
Source: Synthesis - April 16, 2020 Category: Chemistry Authors: Obydennov, Dmitrii L. Viktorova, Viktoria V. Chernyshova, Elena V. Shirinkin, Alexander S. Usachev, Sergey A. Sosnovskikh, Vyacheslav Y. Tags: paper Source Type: research

N-Phosphorylated Pyrrolidines: An Overview of Synthetic Approaches
Conclusions [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - April 14, 2020 Category: Chemistry Authors: Smolobochkin, Andrey V. Gazizov, Almir S. Turmanov, Rakhymzhan A. Abdullaeva, Dinara S. Burilov, Alexander R. Pudovik, Michail A. Tags: short review Source Type: research

Brominated β-Alkoxyvinyl Trihalomethyl Ketones as Promising Synthons in Heterocyclic Synthesis
Conclusions [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - April 14, 2020 Category: Chemistry Authors: Mittersteiner, Mateus Bonacorso, Helio G. Martins, Marcos A. P. Zanatta, Nilo Tags: short review Source Type: research

5-Iodo-1H-1,2,3-triazoles as Versatile Building Blocks
Synthesis DOI: 10.1055/s-0039-1690858 Copper-catalyzed azide–alkyne cycloaddition is a useful tool for the synthesis of both 1,2,3-triazoles and 5-iodo-1H-1,2,3-triazoles starting from either terminal alkynes or iodoalkynes. 5-Iodotriazoles have been recognized as very useful building blocks for the synthesis of diverse 1,4,5-trisubstituted 1,2,3-triazoles. Synthetic application of 5-iodo-1,2,3-triazoles through the creation of a new C–C, C–heteroatom, or C–D(T) bond along with the application areas of both iodotriazoles and products of their modification including radiolabeled compounds are discuss...
Source: Synthesis - April 14, 2020 Category: Chemistry Authors: Danilkina, Natalia A. Govdi, Anastasia I. Balova, Irina A. Tags: short review Source Type: research

Asymmetric Synthesis of Ethers by Catalytic Alkene Hydro ­alkoxy­lation
Conclusion [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - April 14, 2020 Category: Chemistry Authors: Xie, Wen-Bin Li, Zhi Tags: review Source Type: research

Synthesis of a Novel 1,4-Dicarbonyl Scaffold – Ethyl 3-Formyl-4,5-dihydrofuran-2-carboxylate – and Its Application to the Synthesis of Pyridazines
Synthesis DOI: 10.1055/s-0039-1690886 The 1,4-dicarbonyl scaffold ethyl 3-formyl-4,5-dihydrofuran-2-carboxylate was obtained through the rearrangement of the parent ethyl 2-(4,5-dihydrofuran-3-yl)-2-oxoacetate and applied to the synthesis of a series of 7-alkoxy-2,3-dihydrofuro[2,3-d]pyridazines. Twelve pyridazines­ were obtained in yields of up to 70%. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - April 14, 2020 Category: Chemistry Authors: Marangoni, M ário A. Moraes, Paulo A. Camargo, Adriano F. Bonacorso, Helio G. Martins, Marcos A. P. Zanatta, Nilo Tags: paper Source Type: research

Functionalization of Alkenyl C –H Bonds with D2O via Pd(0)/Carboxylic Acid Catalysis
We report herein a simple catalytic method for the extensive labeling of alkenyl C–H bonds through the combination of a palladium(0) complex and a carboxylic acid in the presence of deuterium oxide. The reaction can be applied to a variety of terminal alkenes and the best results are obtained with aryl-substituted examples. This method represents a convenient approach for the preparation of extensively labeled chemicals from the cheapest and safest source of deuterium. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract ...
Source: Synthesis - April 14, 2020 Category: Chemistry Authors: Camedda, Nicola Serafino, Andrea Maggi, Raimondo Bigi, Franca Cera, Gianpiero Maestri, Giovanni Tags: feature Source Type: research

Linked PDF of Table of Contents
Synthesis 2020; 52: V- DOI: 10.1055/s-0040-1707389 © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents (Source: Synthesis)
Source: Synthesis - April 14, 2020 Category: Chemistry Tags: table of contents Source Type: research

Alkynyl Prins and Alkynyl Aza-Prins Annulations: Scope and Synthetic Applications
Synthesis DOI: 10.1055/s-0039-1690869 This review focuses on alkynyl Prins and alkynyl aza-Prins cyclization­ processes, which involve intramolecular coupling of an alkyne with either an oxocarbenium or iminium electrophile. The oxocarbenium or iminium species can be generated through condensation- or elimination-type processes, to achieve an overall bimolecular annulation that enables the synthesis of both oxygen- and nitrogen-containing­ saturated heterocycles with different ring sizes and substitution patterns. Also discussed are cascade processes in which alkynyl Prins heterocyclic adducts react to trigger subs...
Source: Synthesis - April 9, 2020 Category: Chemistry Authors: Abdul-Rashed, Shukree Holt, Connor Frontier, Alison J. Tags: review Source Type: research

Palladium-Catalyzed [3+2] Cycloaddition of Vinylaziridine and Indane-1,3-diones: Diastereo- and Enantioselective Access to Spiro-Pyrrolidines
Synthesis DOI: 10.1055/s-0040-1707472 A mild and efficient palladium-catalyzed [3+2] cycloaddition of vinylaziridine and indane-1,3-diones has been realized. The resulting spiro-pyrrolidines were provided in excellent yields and, with the introduction of the leucine-derived phosphine ligand, moderate to good enantio­- and diastereoselectivities. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synthesis)
Source: Synthesis - April 7, 2020 Category: Chemistry Authors: Vetica, Fabrizio Bailey, Stephen J. Kumar, Mukesh Mahajan, Suruchi von Essen, Carolina Rissanen, Kari Enders, Dieter Tags: paper Source Type: research