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Search for "highly regioselective" in Full Text gives 67 result(s) in Beilstein Journal of Organic Chemistry.

An improved synthesis of adefovir and related analogues

  • David J. Jones,
  • Eileen M. O’Leary and
  • Timothy P. O’Sullivan

Beilstein J. Org. Chem. 2019, 15, 801–810, doi:10.3762/bjoc.15.77

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  • phosphonate (11) was condensed with paraformaldehyde in the presence of catalytic triethylamine (Scheme 2) [41]. Iodide 9 was accessed in two steps from adenine (3). The highly regioselective alkylation of adenine (3) with an excess (4.0 equiv) of 1,2-dibromoethane furnished bromide 12 in 78% yield. Despite
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Published 29 Mar 2019

Application of olefin metathesis in the synthesis of functionalized polyhedral oligomeric silsesquioxanes (POSS) and POSS-containing polymeric materials

  • Patrycja Żak and
  • Cezary Pietraszuk

Beilstein J. Org. Chem. 2019, 15, 310–332, doi:10.3762/bjoc.15.28

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  • , 9-anthracenyl and 2-thienyl have been reported by Marciniec [15]. For all styrene derivatives tested, the procedures described permitted highly regioselective metathesis leading to exclusive formation of the E-isomer. Cross-metathesis experiments were performed under mild reaction conditions (CH2Cl2
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Published 04 Feb 2019

Enhanced single-isomer separation and pseudoenantiomer resolution of new primary rim heterobifunctionalized α-cyclodextrin derivatives

  • Iveta Tichá,
  • Gábor Benkovics,
  • Milo Malanga and
  • Jindřich Jindřich

Beilstein J. Org. Chem. 2018, 14, 2829–2837, doi:10.3762/bjoc.14.261

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  • ). On one hand, a direct bromination of α-CD was performed under Vilsmeier/Haack conditions (reaction 3, Scheme 2) with N-bromosuccinimide (NBS) and Ph3P in N,N-dimethylformamide (DMF). Previous studies have shown that this reaction is highly regioselective for the primary rim of CD [28]. After a fast
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Published 13 Nov 2018

Hydroarylations by cobalt-catalyzed C–H activation

  • Rajagopal Santhoshkumar and
  • Chien-Hong Cheng

Beilstein J. Org. Chem. 2018, 14, 2266–2288, doi:10.3762/bjoc.14.202

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  • addition to imines, aziridines were also amenable to the cobalt-catalyzed hydroarylation reaction (Scheme 36) [96]. Treatment of 2-phenylpyridines 3 with varies aryl-substituted aziridines gave 1,1-diarylethane derivatives 58 in a highly regioselective manner. It is noteworthy that nucleophilic addition
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Published 29 Aug 2018

β-Hydroxy sulfides and their syntheses

  • Mokgethwa B. Marakalala,
  • Edwin M. Mmutlane and
  • Henok H. Kinfe

Beilstein J. Org. Chem. 2018, 14, 1668–1692, doi:10.3762/bjoc.14.143

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  • zinc/aluminium chloride. Movassagh et al. reported another simple, general and highly regioselective one pot synthesis of β-hydroxy sulfides in good yields from the reaction of styrenes and disulfides using Zn/AlCl3 as a catalyst in aqueous CH3CN at 80 °C, in the presence of oxygen as oxidant (Scheme
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Published 05 Jul 2018

Stereoselective nucleophilic addition reactions to cyclic N-acyliminium ions using the indirect cation pool method: Elucidation of stereoselectivity by spectroscopic conformational analysis and DFT calculations

  • Koichi Mitsudo,
  • Junya Yamamoto,
  • Tomoya Akagi,
  • Atsuhiro Yamashita,
  • Masahiro Haisa,
  • Kazuki Yoshioka,
  • Hiroki Mandai,
  • Koji Ueoka,
  • Christian Hempel,
  • Jun-ichi Yoshida and
  • Seiji Suga

Beilstein J. Org. Chem. 2018, 14, 1192–1202, doi:10.3762/bjoc.14.100

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  • = <1:99). Similarly, the reaction of C1 with diethylzinc or allyltributylstannane gave piperidine derivatives 2ab and 2ac with high yields and trans-selectivity (Table 1, entries 2 and 3). Also, the introduction of phenyl or cyano groups in the piperidine core proceeded in a highly regioselective
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Published 24 May 2018

Chlorination of phenylallene derivatives with 1-chloro-1,2-benziodoxol-3-one: synthesis of vicinal-dichlorides and chlorodienes

  • Zhensheng Zhao and
  • Graham K. Murphy

Beilstein J. Org. Chem. 2018, 14, 796–802, doi:10.3762/bjoc.14.67

Graphical Abstract
  • consistent with those achievable by other allene chlorination reactions, it was not investigated further. We next investigated the chlorination of 2a with benziodoxolone 1b [47][48][49], which proved highly regioselective. An initial reaction with 2.2 equiv of 1b in acetonitrile at room temperature failed
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Published 09 Apr 2018

CF3SO2X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF3SO2Na

  • Hélène Guyon,
  • Hélène Chachignon and
  • Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

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Published 19 Dec 2017

Regioselective decarboxylative addition of malonic acid and its mono(thio)esters to 4-trifluoromethylpyrimidin-2(1H)-ones

  • Sergii V. Melnykov,
  • Andrii S. Pataman,
  • Yurii V. Dmytriv,
  • Svitlana V. Shishkina,
  • Mykhailo V. Vovk and
  • Volodymyr A. Sukach

Beilstein J. Org. Chem. 2017, 13, 2617–2625, doi:10.3762/bjoc.13.259

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  • derivatives 10c and 11c by using the general procedure for N1(3)-PMB cleavage (see Scheme 1). Conclusion In conclusion, it has been demonstrated that the efficient and highly regioselective organocatalytic decarboxylative addition of malonic acid or its derivatives to 4-trifluoromethylpyrimidin-2(1H)-ones 2
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Published 07 Dec 2017

Synthesis and supramolecular properties of regioisomers of mononaphthylallyl derivatives of γ-cyclodextrin

  • Markéta Bláhová,
  • Sergey K. Filippov,
  • Lubomír Kováčik,
  • Jiří Horský,
  • Simona Hybelbauerová,
  • Zdenka Syrová,
  • Tomáš Křížek and
  • Jindřich Jindřich

Beilstein J. Org. Chem. 2017, 13, 2509–2520, doi:10.3762/bjoc.13.248

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  • -(naphthalen-2-yl)allyl chloride as the alkylating reagent. Highly regioselective reaction conditions, which differ for each regioisomer in a used base, gave the monosubstituted isomers in yields between 12–19%. Supramolecular properties of these derivatives were studied by DLS, ITC, NMR, and Cryo-TEM
  • supramolecular structures or aggregation. It is to be hoped that the future research not only reveals details of NA-γ-CD interactions but also show how to utilize them in construction of functional supramolecular assemblies. Conclusion New methods for highly regioselective mononaphthylallylation of γ-CD to
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Published 27 Nov 2017

Synthesis, effect of substituents on the regiochemistry and equilibrium studies of tetrazolo[1,5-a]pyrimidine/2-azidopyrimidines

  • Elisandra Scapin,
  • Paulo R. S. Salbego,
  • Caroline R. Bender,
  • Alexandre R. Meyer,
  • Anderson B. Pagliari,
  • Tainára Orlando,
  • Geórgia C. Zimmer,
  • Clarissa P. Frizzo,
  • Helio G. Bonacorso,
  • Nilo Zanatta and
  • Marcos A. P. Martins

Beilstein J. Org. Chem. 2017, 13, 2396–2407, doi:10.3762/bjoc.13.237

Graphical Abstract
  • ) was highly regioselective and yielded tetrazolo[1,5-a]pyrimidines 5h,i, in which R = CF3 and CCl3 and presented exclusively R at the 7-position of the heterocyclic ring (Table 2). The tetrazolo[1,5-a]pyrimidine2-azidopyrimidine (34) equilibrium will be discussed in detail later in this article. All
  • showed that the structure of the R group affects the regiochemistry of the products formed. The β-enaminones 1a–g (R = aryl) result predominantly in 5-aryl-substituted tetrazolo[1,5-a]pyrimidines 3a–g. β-Enaminones 1h,i (R = CF3 and CCl3) result in a highly regioselective synthesis of tetrazolo[1,5-a
  • , our research group demonstrated a highly regioselective synthesis of a series of trifluoromethylated tetrazolo[1,5-a]pyrimidines with potent antimicrobial activity [37]. The reaction between several β-alkoxyvinyl trifluoromethyl ketones [CF3C(O)CH=C(R)OCH3] (in which R = Ph, 4-F–C6H4, 4-Cl–C6H4, 4-Br
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Published 10 Nov 2017

Difunctionalization of alkenes with iodine and tert-butyl hydroperoxide (TBHP) at room temperature for the synthesis of 1-(tert-butylperoxy)-2-iodoethanes

  • Hao Wang,
  • Cui Chen,
  • Weibing Liu and
  • Zhibo Zhu

Beilstein J. Org. Chem. 2017, 13, 2023–2027, doi:10.3762/bjoc.13.200

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  • methods to construct peroxides are still highly desirable and valuable, and highly regioselective and efficient syntheses of peroxides with structural control are still difficult to achieve. Herein, we report a metal-free iodination–peroxidation reaction for the direct vicinal difunctionalization of
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Published 28 Sep 2017

Mechanochemical synthesis of small organic molecules

  • Tapas Kumar Achar,
  • Anima Bose and
  • Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

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  • mechanosynthesis of organometallic complexes are shown. Ćurić and co-workers reported the first mechanochemical activation of a C–H bond of unsymmetrical azobenzene with Pd(OAc)2 [178]. The cyclopalladation process was highly regioselective and the rate of palladation was also faster than traditional solution
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Published 11 Sep 2017

Switchable highly regioselective synthesis of 3,4-dihydroquinoxalin-2(1H)ones from o-phenylenediamines and aroylpyruvates

  • Juraj Dobiaš,
  • Marek Ondruš,
  • Gabriela Addová and
  • Andrej Boháč

Beilstein J. Org. Chem. 2017, 13, 1350–1360, doi:10.3762/bjoc.13.132

Graphical Abstract
  • , rt, 3 days), differing only by the additives p-TsOH or HOBt/DIC (hydroxybenzotriazole/N,N’-diisopropylcarbodiimide). Both selected methods are simple, general and highly regioselective (72–97%). A mechanism for the regioselectivity was also proposed and discussed. This study can be used as a guide
  • or the contrary regioselectivity of activated species 12c,d (prepared in situ from appropriate 12 by DMAP – 12c or HOBt/DIC additives – 12d) (Scheme 6). Conclusion Simple reaction conditions were discovered for predictable and switchable highly regioselective synthesis of 3,4-dihydroquinoxaline-2(1H
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Published 10 Jul 2017

Regiochemistry of cyclocondensation reactions in the synthesis of polyazaheterocycles

  • Patrick T. Campos,
  • Leticia V. Rodrigues,
  • Andrei L. Belladona,
  • Caroline R. Bender,
  • Juliana S. Bitencurt,
  • Fernanda A. Rosa,
  • Davi F. Back,
  • Helio G. Bonacorso,
  • Nilo Zanatta,
  • Clarissa P. Frizzo and
  • Marcos A. P. Martins

Beilstein J. Org. Chem. 2017, 13, 257–266, doi:10.3762/bjoc.13.29

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  • product 7 was observed by precipitation. After completion of the reaction, the solvent was evaporated and the residue purified by column chromatography. All products 5–7 were obtained in a highly regioselective manner and in good yields. Analogues of 5–7 with a carbonyl substituent have been previously
  • between β-enaminodiketone and aromatic amidines was highly regioselective. Results obtained from DFT-B3LYP theoretical calculations were in agreement with the experimental data. Using data from HOMO and LUMO coefficients, it was possible to conclude that the reaction is controlled by frontier molecular
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Published 10 Feb 2017

First DMAP-mediated direct conversion of Morita–Baylis–Hillman alcohols into γ-ketoallylphosphonates: Synthesis of γ-aminoallylphosphonates

  • Marwa Ayadi,
  • Haitham Elleuch,
  • Emmanuel Vrancken and
  • Farhat Rezgui

Beilstein J. Org. Chem. 2016, 12, 2906–2915, doi:10.3762/bjoc.12.290

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  • conditions, is described herein for the first time. Subsequently, a highly regioselective Luche reduction of the primary phosphonate 2a (R = H) gave the corresponding γ-hydroxyallylphosphonate 5 that further reacted with tosylamines in the presence of diiodine (15 mol %) as a catalyst, affording the
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Published 30 Dec 2016

An effective one-pot access to polynuclear dispiroheterocyclic structures comprising pyrrolidinyloxindole and imidazothiazolotriazine moieties via a 1,3-dipolar cycloaddition strategy

  • Alexei N. Izmest’ev,
  • Galina A. Gazieva,
  • Natalya V. Sigay,
  • Sergei A. Serkov,
  • Valentina A. Karnoukhova,
  • Vadim V. Kachala,
  • Alexander S. Shashkov,
  • Igor E. Zanin,
  • Angelina N. Kravchenko and
  • Nina N. Makhova

Beilstein J. Org. Chem. 2016, 12, 2240–2249, doi:10.3762/bjoc.12.216

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  • phase (see Supporting Information File 1). Thus, the cycloaddition of azomethine ylides was found to be highly regioselective, as the electron-rich carbon of the dipole adds to the β-carbon of the α,β-unsaturated moiety of dipolarophile 1. Further the reaction is diastereoselective, as only one
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Published 24 Oct 2016

Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

  • Lucie Brulíková,
  • Aidan Harrison,
  • Marvin J. Miller and
  • Jan Hlaváč

Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184

Graphical Abstract
  • nature of these substituents [20][94]. This can be seen for the hetero-Diels–Alder reaction of disubstituted diene 51 with p-chloronitrosobenzene (52) to give only the proximal isomer 53 (Scheme 13). Recently, the Kouklovsky group reported a highly regioselective nitroso hetero-Diels–Alder cycloaddition
  • ). Regiocontrol of the nitroso hetero-Diels–Alder reaction As discussed above, the nitroso hetero-Diels–Alder reaction can be highly regioselective due to the influences of diene substituents and electronic effects. However, reports on the specific regiocontrol of the reaction are rare. In general, the
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Published 01 Sep 2016

Beta-hydroxyphosphonate ribonucleoside analogues derived from 4-substituted-1,2,3-triazoles as IMP/GMP mimics: synthesis and biological evaluation

  • Tai Nguyen Van,
  • Audrey Hospital,
  • Corinne Lionne,
  • Lars P. Jordheim,
  • Charles Dumontet,
  • Christian Périgaud,
  • Laurent Chaloin and
  • Suzanne Peyrottes

Beilstein J. Org. Chem. 2016, 12, 1476–1486, doi:10.3762/bjoc.12.144

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  • and 5 demonstrates that cycloaddition of terminal alkynes catalysed by Cu(I) were highly regioselective and led to 4-substituted-1,2,3-triazoles in the β-hydroxyphosphonate series. Then, on the basis of the study reported by Hudson et al., we performed extensive 2D-NMR experiments on compounds 3h and
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Published 18 Jul 2016

Regioselective palladium-catalyzed ring-opening reactions of C1-substituted oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylates

  • Michael Edmunds,
  • Mohammed Abdul Raheem,
  • Rebecca Boutin,
  • Katrina Tait and
  • William Tam

Beilstein J. Org. Chem. 2016, 12, 239–244, doi:10.3762/bjoc.12.25

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  • the steric bulk on the bridgehead carbon decreased the yield. These reactions were found to be highly regioselective, giving only one of the two possible regioisomers in all cases. A diverse collection of novel, highly substituted biphenyl derivatives were obtained. Keywords: aryl iodides
  • regenerating the catalyst. Compound 10 rapidly undergoes base-catalyzed dehydration to give the final product 3. Conclusion In conclusion, we have demonstrated the first examples of palladium-catalyzed ring-opening reactions of 1 with aryl iodides. This reaction was highly regioselective giving only one of the
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Published 09 Feb 2016

Supramolecular structures based on regioisomers of cinnamyl-α-cyclodextrins – new media for capillary separation techniques

  • Gabor Benkovics,
  • Ondrej Hodek,
  • Martina Havlikova,
  • Zuzana Bosakova,
  • Pavel Coufal,
  • Milo Malanga,
  • Eva Fenyvesi,
  • Andras Darcsi,
  • Szabolcs Beni and
  • Jindrich Jindrich

Beilstein J. Org. Chem. 2016, 12, 97–109, doi:10.3762/bjoc.12.11

Graphical Abstract
  • not able to achieve the high regiospecificity of the monocinnamylation which we described for β-CD earlier [11]. In the case of β-CD the only monosubstituted isomer obtained was 3-O-Cin-β-CD in 30% isolated yield. This result was explained by a highly regioselective complexation of the alkylation
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Published 19 Jan 2016

Recent advances in copper-catalyzed asymmetric coupling reactions

  • Fengtao Zhou and
  • Qian Cai

Beilstein J. Org. Chem. 2015, 11, 2600–2615, doi:10.3762/bjoc.11.280

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  • bonds [63]. Recently, the copper-catalyzed enantioselective allylic substitutions with organoboron compounds have seen impressive progress. In 2011, Hayashi et al. [64] developed a new efficient method for the highly regioselective and enantioselective construction of tertiary carbon stereocenters by
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Published 15 Dec 2015

Stereoselective synthesis of hernandulcin, peroxylippidulcine A, lippidulcines A, B and C and taste evaluation

  • Marco G. Rigamonti and
  • Francesco G. Gatti

Beilstein J. Org. Chem. 2015, 11, 2117–2124, doi:10.3762/bjoc.11.228

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  • has been prepared on a multigram scale. The previously assigned absolute configurations have been confirmed. The key steps of this synthesis are based on a modified version of the Kornblum–DeLaMare rearrangement, and on a highly regioselective and stereoselective ketone reduction with the MeCBS
  • stereochemical configurations that have been previously assigned. The key steps are: i) a modified version of the Kornblum–DeLaMare rearrangement, promoted by the O-silylation of the hydroperoxy group, and ii) an highly regioselective and stereoselective reduction of the exocyclic carbonyl group of ketone 14
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Published 05 Nov 2015

Chiral phosphines in nucleophilic organocatalysis

  • Yumei Xiao,
  • Zhanhu Sun,
  • Hongchao Guo and
  • Ohyun Kwon

Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218

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  • many have been applied in medicine and other fields. Using the axially chiral spirophosphine D1, Shi and co-workers accomplished highly regioselective, diastereoselective, and enantioselective [3 + 2] annulations of a series of alkylidene azlactones with allenoates (Scheme 18) [49]. Under mild
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Published 04 Sep 2014

Regioselective SN2' Mitsunobu reaction of Morita–Baylis–Hillman alcohols: A facile and stereoselective synthesis of α-alkylidene-β-hydrazino acid derivatives

  • Silong Xu,
  • Jian Shang,
  • Junjie Zhang and
  • Yuhai Tang

Beilstein J. Org. Chem. 2014, 10, 990–995, doi:10.3762/bjoc.10.98

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  • Silong Xu Jian Shang Junjie Zhang Yuhai Tang Department of Chemistry, School of Science, Xi’an Jiaotong University, Xi’an 710049, P. R. China 10.3762/bjoc.10.98 Abstract A highly regioselective SN2' Mitsunobu reaction between Morita–Baylis–Hillman (MBH) alcohols, azodicarboxylates, and
  • first direct conversion of MBH alcohols into hydrazines. In addition, the normal SN2 Mitsunobu reaction [35][36] product 5, namely, diethyl 1-(2-(ethoxycarbonyl)-1-phenylallyl)hydrazine-1,2-dicarboxylate, could not be detected in the reaction mixture, which suggested a highly regioselective SN2
  • attracted considerable interest from the organic chemistry community due to their great synthetic potential being complementary to the Mitsunobu reactions. This report accordingly adds to a new valuable example of SN2' Mitsunobu reactions. Conclusion In conclusion, we have developed a highly regioselective
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Published 30 Apr 2014
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