Change search
Refine search result
1 - 18 of 18
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Blid, Jan
    et al.
    KTH, Superseded Departments, Chemistry.
    Somfai, Peter
    KTH, Superseded Departments, Chemistry.
    Lewis Acid Mediated [2,3]-Sigmatropic Rearrangement of Allylic Ammonium Ylides2003In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 44, no 15, p. 3159-3162Article in journal (Refereed)
    Abstract [en]

    An investigation of the Lewis acid mediated [2,3]-sigmatropic rearrangement of allylic ammonium ylides has been conducted by employing various bases and boron Lewis acids. Using BBr3 together with the phosphazene base 6, various allylic amines could be rearranged in good yields with low to excellent diastereoselectivity.

  • 2.
    Blomkvist, Björn
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Dinér, Peter
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    HBF4 center dot DEE-catalyzed formation of sulfinyl imines: Synthesis and mechanistic studies2018In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 59, no 13, p. 1249-1253Article in journal (Refereed)
    Abstract [en]

    A mild acid-catalysed method is reported for the formation of sulfinyl imines from tert-butanesulfinamide and aromatic or aliphatic aldehydes using tetrafluoroboric acid diethyletherate (10 mol%) in dichloromethane. Reactions were performed at room temperature and gave the corresponding sulfinyl imines in excellent yield after 2 h. A DFT study was performed and a mechanism for the reaction is postulated. 

  • 3.
    Borg, Tessie
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Timmer, Brian
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Somfai, Peter
    Diastereoselective formation of 2,3,4,5-tetrasubstituted tetrahydrofurans by a Lewis acid promoted addition of C3-substituted 1,3-bis(silyl)propenes to aldehydes2013In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 54, no 30, p. 3916-3918Article in journal (Refereed)
    Abstract [en]

    A mild, efficient, Lewis acid promoted addition of C3-substituted 1,3-bis(silyl)propenes to aldehydes to provide the corresponding 2,3,4,5-tetrasubstituted tetrahydrofurans in excellent stereoselectivity is reported.

  • 4.
    Chen, Shan
    et al.
    KTH, School of Biotechnology (BIO), Industrial Biotechnology. Hainan University, China.
    Liu, Fuyan
    Zhang, Kuan
    Huang, Hansheng
    Wang, Huani
    Zhou, Jiaying
    Zhang, Jing
    Gong, Yiwei
    Zhang, Dela
    Chen, Yiping
    Lin, Chang
    Wang, Bo
    An efficient enzymatic aminolysis for kinetic resolution of aromatic alpha-hydroxyl acid in non-aqueous media2016In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 57, no 48, p. 5312-5314Article in journal (Refereed)
    Abstract [en]

    A new and highly efficient enzymatic aminolysis approach for kinetic resolution of aromatic a-hydroxy acid in non-aqueous media has been developed. The corresponding alpha-hydroxyl acid ester was employed as the substrate, and commercially available Candida antarctica lipase B is used as the biocatalyst, anhydrous ammonia is the resolving agent. Reactions can be proceeded smoothly in organic solvent at ambient temperatures. High concentration of substrate is allowed due to the application of organic media and the products are obtained in yields of up to 49% with ee values of up to 99%, and with E value of >300, representing an appealing and promising protocol for large-scale preparations.

  • 5. Hortala, L.
    et al.
    Moberg, Christina
    KTH, Superseded Departments, Chemistry.
    Levacher, V.
    Bourguignon, J.
    Dupas, G.
    Acyl transfer of 8-acetoxy-2-oxazolinylquinoline assisted by hydrogen bonding formation2002In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 43, no 6, p. 1027-1029Article in journal (Refereed)
    Abstract [en]

    A significant acceleration of acyl transfer has been achieved on 8-acetoxy-2-oxazolinylquinoline in the presence of benzylamine. Comparison of the aminolysis by the new acylating reagent with that of 8-acetoxyquinoline and 8-acetoxyquinoline-2-carbonitrile has been carried out. The results of these experiments suggest that the proximity of a supplementary basic atom to the ester group increases the participation effect of the basic site mainly by formation of a possible second hydrogen bond. The association constant of benzylamine into the basic cavity of 8-methoxy-2-oxazolinylquinoline (K-d = 80 M-1) has been measured by H-1 NMR titration experiments.

  • 6. Langlet, Abraham
    et al.
    Latypov, Nikolaj
    Wellmar, Ulf
    Goede, P.
    Bergman, Jan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Synthesis and reaction of 5,5-dinitrobarbituric acid2000In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Tetrahedron letters, Vol. 41, no 12, p. 2011-2013Article in journal (Refereed)
    Abstract [en]

    Nitration of barbituric acid at 40°C gave the previously unknown 5,5- dinitrobarbituric acid (3), which readily underwent hydrolysis to dinitroacetylurea (5), which in turn could be hydrolysed in basic media to the potassium salt of dinitromethane. Alloxane was prepared in a one step procedure by thermal decomposition of 5,5-dinitrobarbituric acid in hot acetic acid.

  • 7. Li, S. -F
    et al.
    Yang, X. -C
    Cheng, M.
    Zhao, J. -H
    Wang, Y.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Novel D–π–A type II organic sensitizers for dye sensitized solar cells2012In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 53, no 27, p. 3425-3428Article in journal (Refereed)
    Abstract [en]

    Four organic donor-Ï€-conjugated-acceptor (D-Ï€-A) type II dyes with different thiophene linkers are reported for dye sensitized solar cells (DSSCs). For the first time, a donor (triphenylamine) was introduced in type II sensitizers, and 2-hydroxybenzonitrile as acceptor/anchoring moiety was covalently linked TiO 2 particles. The dye LS203 in this series gives the best solar energy conversion efficiency of 3.4%, with J sc = 7.4 mA cm -2, V oc = 0.67 V, FF = 0.69, the maximum IPCE value reaches 66.9%.

  • 8. Liljenberg, Magnus
    et al.
    Brinck, Tore
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Physical Chemistry (closed 20110630).
    Herschend, Björn
    Rein, Tobias
    Rockwell, Glen
    Svensson, Mats
    A pragmatic procedure for predicting regioselectivity in nucleophilic substitution of aromatic fluorides2011In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 52, p. 3150-3153Article in journal (Refereed)
    Abstract [en]

    The scope and limitations of a method for predicting the regioisomer distribution in kinetically controlled nucleophilic substitution reactions of aromatic fluorides have been investigated. This method is based on calculating the relative stabilities of the isomeric σ-complex intermediates using DFT. A wide set of substrates and anionic nucleophiles have been investigated. Predictions from this method can be used quantitatively—these agree to an average accuracy of ±0.5 kcal/mol with experimental observations in eleven of the twelve investigated reactions.

  • 9. Olofsson, B.
    et al.
    Somfai, Peter
    KTH, Superseded Departments, Chemistry.
    Determination of the relative configuration of vic-amino alcohols2003In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 44, no 6, p. 1279-1281Article in journal (Refereed)
    Abstract [en]

    A large set of syn- and anti-1,2-amino alcohols has been synthesized. Upon comparison of the CHO and CHN H-1 NMR shifts a general trend has been observed, making it possible to determine the relative configuration of 1,2-amino alcohols without derivatization or shift reagents.

  • 10. Ray, C. A.
    et al.
    Risberg, E.
    Somfai, Peter
    KTH, Superseded Departments, Chemistry.
    Lewis acid-catalyzed hetero Diels-Alder cycloadditions of 3-alkyl, 3-phenyl and 3-carboxylated 2H-azirines2001In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 42, no 52, p. 9289-9291Article in journal (Refereed)
    Abstract [en]

    Activation by Lewis acids of 3-alkyl and 3-phenyl 2H-azirines promotes their participation in hetero Diels-Alder reactions with a variety of dienes. This methodology circumvents the previous requirement of an electron-withdrawing carboxyl moiety at the 3-position of the 2H-azirine.

  • 11.
    Sakulsombat, Morakot
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Angelin, Marcus
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Ramström, Olof
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Tandem reversible addition-intramolecular lactonization for the synthesis of 3-functionalized phthalides2010In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 51, no 1, p. 75-78Article in journal (Refereed)
    Abstract [en]

    A new tandem process based on reversible nucleophilic addition and intramolecular lactonization of methyl 2-formylbenzoate leads to the efficient synthesis of 3-functionalized phthalides, which are important precursors for the synthesis of quinone skeletons via Hauser–Kraus annulation. The reactions are successfully carried out under mild conditions in single operations.

  • 12. Shi, Yu
    et al.
    Li, Xiaoyu
    Liu, Jianhui
    Jiang, Wenfeng
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    PdCl2-catalyzed cross-coupling reaction of arylacetylene iodides with arylboronic acids to diarylacetylenes2010In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 51, no 28, p. 3626-3628Article in journal (Refereed)
    Abstract [en]

    Anew Suzuki-type cross-coupling reaction between 1-iodo-2-arylalkynes and arylboronic acids to afford a wide variety of functionalized diarylacetylenes in a mild reaction condition was developed. The reaction was catalyzed by a small amount of a structurally simple, commercially available, and stable PdCl2. This unique sp-sp(2) carbon-carbon bond formation provides a new protocol for the synthesis of diarylacetylenes, which is a new addition to the Suzuki cross-coupling reaction. (C) 2010 Elsevier Ltd. All rights reserved.

  • 13. Timen, A. S.
    et al.
    Risberg, E.
    Somfai, Peter
    KTH, Superseded Departments, Chemistry.
    Improved procedure for cyclization of vinyl azides into 3-substituted-2H-azirines2003In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 44, no 28, p. 5339-5341Article in journal (Refereed)
    Abstract [en]

    A significantly improved procedure for the preparation of 3-substituted 2H-azirines has been developed. By cyclization of the corresponding vinyl azides in low boiling solvents in closed vessels at elevated temperature, high purity, short reaction time and simple isolation of the product were achieved.

  • 14.
    Tuzina, Pavel
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Somfai, Peter
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Lewis acid mediated 1,2 -rearrangement of ammonium ylides2007In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 48, no 28, p. 4947-4949Article in journal (Refereed)
    Abstract [en]

    The first example of Lewis acid mediated [1,2]-rearrangement of various glycine derivatives has been developed. A brief study of steric and electronic properties of the migrating group is presented. The corresponding amides were obtained in good yields and in the case of substrate 4d, moderate diastereoselectivity was observed.

  • 15.
    Tuzina, Pavel
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Somfai, Peter
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Lewis acid-promoted carbonyl addition of 1,3-bis(silyl)propenes2008In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 49, no 48, p. 6882-6884Article in journal (Refereed)
    Abstract [en]

    A novel synthetic protocol for Lewis acid-promoted addition of 1,3-bis(silyl)propenes to N-phenyl glyoxylamide and ethyl glyoxylate is developed. The reaction does not appear to be influenced by the steric bulk of the 1,3-bis(silyl)propenes, and represents a new approach to vinylation of glyoxylates; the products are obtained in good yields.

  • 16.
    von Kieseritzky, Fredrik
    et al.
    KTH, Superseded Departments, Chemistry.
    Allared, Fredrik
    KTH, Superseded Departments, Chemistry.
    Dahlstedt, Emma
    KTH, Superseded Departments, Chemistry.
    Hellberg, Jonas
    KTH, Superseded Departments, Chemistry.
    Simple one-step synthesis of 3,4-dimethoxythiophene and its conversion into 3,4-ethylenedioxythiophene (EDOT)2004In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 45, no 31, p. 6049-6050Article in journal (Refereed)
    Abstract [en]

    3,4-Dimethoxythiophene (2) was synthesized in one-step front readily available bulk chemicals via a ring closure reaction, and was then trans-etherified with ethylene glycol to give 3,4-ethylenedioxythiophene (3) (EDOT).

  • 17. Yang, Xichuan
    et al.
    Jiang, Xiao
    Zhao, Changzhi
    Chen, Ruikui
    Qin, Peng
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Donor-acceptor molecules containing thiophene chromophore: synthesis, spectroscopic study and electrogenerated chemiluminescence2006In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 47, no 28, p. 4961-4964Article in journal (Refereed)
    Abstract [en]

    Donor-acceptor molecules containing thiophene chromophore with remarkably large Stokes shift (> 210 nm) have been found to exhibit strong and stable ECL emission via the singlet excited state without the addition of any co-reactant or a second compound.

  • 18. Zhang, Xiang
    et al.
    Jia, Yin-Bao
    Lu, Xiao-Bing
    Li, Bo
    Wang, Hui
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Intramolecularly two-centered cooperation catalysis for the synthesis of cyclic carbonates from CO2 and epoxides2008In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 49, no 46, p. 6589-6592Article in journal (Refereed)
    Abstract [en]

    A catalyst systern containing an electrophilic center and a sterically hindered nUcleophilic center in one molecule was applied to the cycloaddition reaction of CO2 and epoxides. This intramolecularly two-centered cooperation catalyst showed activity even at a high [epoxide]/[catalyst] ratio up to 50000 under mild conditions such as solvent-free, ambient temperature, and low CO2 pressure. The reaction of CO2 with (S)-propylene oxide at 80 degrees C in the presence of the bifunctional catalyst gives (S)-propylene carbonate in 96% ee with retention of stereochemistry.

1 - 18 of 18
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf