76
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Zwanenburg B, Philipse H, Verstappen M, Gieling R. Sulfur substituted Small-ring Heterocycles. PHOSPHORUS SULFUR 2008. [DOI: 10.1080/10426509708545594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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77
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Bonini BF, Capitò E, Comes-Franchini M, Fochi M, Ricci A, Zwanenburg B. Aziridin-2-yl methanols as organocatalysts in Diels–Alder reactions and Friedel–Crafts alkylations of N-methyl-pyrrole and N-methyl-indole. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.tetasy.2006.11.028] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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78
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Bonini BF, Beulen MWJ, Comes-franchini M, Mazzanti G, Van De Voort HHJM, Zwanenburg B. A NOVEL SYNTHESIS OF THIONO-ESTER S-OXIDES BY SUBSTITUTION OF CHLORINE IN CHLOROSULFINES. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426509608029661] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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79
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Joseph CC, Zwanenburg B, Chittenden GJF. A Rapid and Facile Preparation of Methyl 4,6- O -Benzylidene-α-d-glucopyranoside and Some Related Compounds. SYNTHETIC COMMUN 2006. [DOI: 10.1081/scc-120015781] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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80
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Wijtmans M, Rosenthal SJ, Zwanenburg B, Porter NA. Visible Light Excitation of CdSe Nanocrystals Triggers the Release of Coumarin from Cinnamate Surface Ligands. J Am Chem Soc 2006; 128:11720-6. [PMID: 16939297 DOI: 10.1021/ja063562c] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The photochemical properties of organic ligands on the surface of nanocrystalline CdSe particles were examined. A number of thiols carrying a substituted cinnamate tail was synthesized. In solution, these cinnamate compounds undergo light-induced (374 nm) E-Z isomerization, followed by a nonphotolytic lactonization to give highly fluorescent coumarin. The cinnamate-thiols were successfully exchanged onto the CdSe nanocrystal, and the photochemical behavior of these conjugates was studied. Upon aerobic photolysis at 374 nm, the surface cinnamates released coumarin accompanied by rapid nanocrystal degradation. This degradation was not observed under similar anaerobic conditions or when the organic ligands did not contain the cinnamate group. Surprisingly, very similar results were obtained upon irradiation at visible wavelengths at which the cinnamate has no absorption. With the aid of UV-visible absorption spectroscopy, fluorescence spectroscopy, and electrochemistry, a unified theory for both the increased photoinstability of the nanocrystal as well as the coumarin release was proposed. It involves cinnamate radical anions on the CdSe surface, formed upon electron transfer from the excited nanocrystal to the surface cinnamate, undergoing E-Z isomerization. Practically, this results in the remarkable ability to release coumarin from nanocrystal ligands simply by exciting the nanocrystal with visible light. This new photorelease protocol not only aids in the understanding of fundamental nanocrystal-ligand interactions but may also offer new opportunities in the areas of drug delivery and imaging.
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81
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Sung'hwa F, Strik A, Regeling H, Zwanenburg B, Chittenden GJF. Synthesis of 2(R),3-dihydroxypropyl and 2(R),3(R)-dihydroxybutyl β-d-fructopyranosides and some derivatives. Carbohydr Res 2006; 341:846-54. [PMID: 16529731 DOI: 10.1016/j.carres.2006.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2005] [Revised: 01/24/2006] [Accepted: 02/09/2006] [Indexed: 10/24/2022]
Abstract
The synthesis of 2(R),3-dihydroxypropyl and 2(R),3(R)-dihydroxybutyl beta-d-fructopyranosides, and some derivatives, employing Sharpless-type catalytic asymmetric dihydroxylation procedures is described. Some aspects of the reactions, including stereoselectivities and chemical evidence for the assigned stereochemistry of the main products are reported.
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82
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Thijs L, Zwanenburg B. Rubrenolide, total synthesis and revision of its reported stereochemical structure. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.04.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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83
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Lucassen A, Zwanenburg B. Ring Contraction of 3,6-Dihydro-2H-thiopyrans to Thiolanes by an Iodo-Oxyacylation Reaction. European J Org Chem 2004. [DOI: 10.1002/ejoc.200300166] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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84
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Vermeulen M, Zwanenburg B, Chittenden GJF, Verhagen H. Synthesis of isothiocyanate-derived mercapturic acids. Eur J Med Chem 2003; 38:729-37. [PMID: 12932904 DOI: 10.1016/s0223-5234(03)00141-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Twelve mercapturic acids derived from saturated and unsaturated aliphatic and aromatic isothiocyanates were synthesised, by adding isothiocyanate to a solution of N-acetyl-L-cysteine and sodium bicarbonate, in a typical yield of 77%. Isothiocyanates were synthesised first by adding the corresponding alkyl bromide to phthalimide potassium salt. The obtained N-alkyl-phthalimide was hydrazinolysed yielding the alkyl amine, which subsequently was reacted with thiophosgene yielding the isothiocyanate with an overall yield of 16%. Mercapturic acids in urine can serve as a biomarker of intake to determine the health promoting potential of isothiocyanates present in cruciferous vegetables.
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85
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Keltjens R, Vadivel S, Gelder R, Klunder A, Zwanenburg B. Diastereoselective Zinc-Mediated Barbier-Type Allylation and Propargylation of 3-Formylcephalosporins. European J Org Chem 2003. [DOI: 10.1002/ejoc.200210503] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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86
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Reizelman A, Wigchert SC, del-Bianco C, Zwanenburg B. Synthesis and bioactivity of labelled germination stimulants for the isolation and identification of the strigolactone receptor. Org Biomol Chem 2003; 1:950-9. [PMID: 12929633 DOI: 10.1039/b210678g] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Strigolactones are highly potent germination stimulants for seeds of the parasitic weeds Striga and Orobanche spp. The induction of seed germination is thought to proceed via a receptor-mediated mechanism. Isolation and purification of the strigolactone receptor by affinity chromatography using immobilized avidin or streptavidin requires a biotin labelled strigolactone analogue. For this purpose biotin has been attached, directly as well as indirectly, via a hydrophilic linker to the amino function of optically active amino-GR24. Using the same amino substituted synthetic stimulant GR24, labelled stimulants have been prepared which may be suitable for the identification of the receptor by means of fluorescence correlation spectroscopy, scanning force microscopy or photoaffinity techniques. Bioassays of the labelled stimulants reveal that the germination activity on seeds of Striga hermonthica is retained. Crystal data for the diastereoisomer (+)-8 are reported.
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87
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Joseph CC, Regeling H, Zwanenburg B, Chittenden GJ. Syntheses of (3R,4R,5R,6R)-tetrahydroxyazepane (1,6-dideoxy-1,6-imino-d-mannitol) and (3S,4R,5R,6R)-tetrahydroxyazepane (1,6-dideoxy-1,6-imino-d-glucitol). Tetrahedron 2002. [DOI: 10.1016/s0040-4020(02)00757-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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88
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Joseph CC, Regeling H, Zwanenburg B, Chittenden GJF. Synthesis of 1-deoxy-L-gulonojirimycin (L-guloDNJ) and 1-deoxy-D-talonojirimycin (D-taloDNJ). Carbohydr Res 2002; 337:1083-7. [PMID: 12062523 DOI: 10.1016/s0008-6215(02)00100-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Carbohydrate based syntheses of azasugars with unusual configurations viz. 1,5-dideoxy-1,5-imino-L-gulitol (L-guloDNJ) and 1,5-dideoxy-1,5-imino-L-talitol (L-taloDNJ) are reported, from D-mannose and D-fructose, respectively. The key steps in both syntheses involved reductive aminative cyclizations. Thus, L-guloDNJ was obtained by reduction of 2,3;4,6-di-O-isopropylidene-5-O-p-toluenesulfonyl-D-mannononitrile with LiAlH(4) in DME to give the protected azasugar which upon hydrolysis with HCl afforded crystalline L-guloDNJ as the HCl salt in 29% overall yield. Reduction of 6-azido-1-O-tert-butyldimethylsilyl-2,3-O-isopropylidene-beta-D-ribohexulofuranose obtained from D-fructose in six steps, followed by treatment with HCl, afforded L-taloDNJ as an HCl salt in approximately 10% overall yield.
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89
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Weenen H, Nkunya MHH, El-Fadl AA, Harkema S, Zwanenburg B. Lucidene, a bis(benzopyranyl) sesquiterpene from Uvaria lucida ssp. lucida. J Org Chem 2002. [DOI: 10.1021/jo00304a023] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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90
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Schank K, Frisch A, Zwanenburg B. .alpha.-Oxo sulfones. 4. Correction of a pretended .alpha.-oxo sulfone by an unambiguous synthesis of the revised structure. J Org Chem 2002. [DOI: 10.1021/jo00172a027] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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91
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Lemmens JM, Blommerde WWJM, Thijs L, Zwanenburg B. Synthesis of .alpha.,.beta.-epoxyacyl azides and their rearrangement to epoxy isocyanates and 3- and 4-oxazolin-2-ones. J Org Chem 2002. [DOI: 10.1021/jo00186a030] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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92
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Lenz BG, Regeling H, Van Rozendaal HLM, Zwanenburg B. Synthesis of .alpha.-oxo sulfines from enol silyl ethers and thionyl chloride. J Org Chem 2002. [DOI: 10.1021/jo00216a024] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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93
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Porskamp PATW, Lammerink BHM, Zwanenburg B. Synthesis and reactions of phosphoryl-substituted sulfines. J Org Chem 2002. [DOI: 10.1021/jo00176a010] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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94
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Van den Broek LAGM, Porskamp PATW, Haltiwanger RC, Zwanenburg B. Asymmetric Diels-Alder reactions with sulfines derived from proline. J Org Chem 2002. [DOI: 10.1021/jo00184a004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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95
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Porskamp PATW, Zwanenburg B. Synthesis of thione S-imides by alkylidenation of sulfinylanilines and imination of sulfines. J Org Chem 2002. [DOI: 10.1021/jo00172a028] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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96
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Leemhuis FMC, Thijs L, Zwanenburg B. Total synthesis of patulolide C and its homo-, nor, and iso analogs. J Org Chem 2002. [DOI: 10.1021/jo00077a047] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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97
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Buijnsters P, García Rodríguez C, Willighagen E, Sommerdijk N, Kremer A, Camilleri P, Feiters M, Nolte R, Zwanenburg B. Cationic Gemini Surfactants Based on Tartaric Acid: Synthesis, Aggregation, Monolayer Behaviour, and Interaction with DNA. European J Org Chem 2002. [DOI: 10.1002/1099-0690(200204)2002:8<1397::aid-ejoc1397>3.0.co;2-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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98
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Reizelman A, Zwanenburg B. An Efficient Enantioselective Synthesis of Strigolactones with a Palladium-Catalyzed Asymmetric Coupling as the Key Step. European J Org Chem 2002. [DOI: 10.1002/1099-0690(200203)2002:5<810::aid-ejoc810>3.0.co;2-u] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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99
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Righi P, Scardovi N, Marotta E, ten Holte P, Zwanenburg B. Solution- and solid-phase synthesis of 4-hydroxy-4,5-dihydroisoxazole derivatives from enantiomerically pure N-tosyl-2,3-aziridine alcohols. Org Lett 2002; 4:497-500. [PMID: 11843575 DOI: 10.1021/ol0170152] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] Enantiomerically pure N-tosyl-2,3-aziridine alcohols are directly converted into 4-hydroxy-4,5-dihydroisoxazole 2-oxides through oxidation to the corresponding aldehydes followed by in situ tandem nitroaldol-intramolecular cyclization. This study was concerned with (i) the selection of a suitable aziridine activation, (ii) the preparation of the target 4-hydroxy-4,5-dihydroisoxazole derivatives in solution, and (iii) the elaboration of a solid-phase process using hydroxy Merrifield-supported nitroacetic acid ester.
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100
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Kemperman G, de Gelder R, Dommerholt F, Klunder A, Zwanenburg B. Molecular Selectivity and Cooperativity in the Clathrate-Type Complexation of Cephradine. European J Org Chem 2002. [DOI: 10.1002/1099-0690(20021)2002:2<345::aid-ejoc345>3.0.co;2-v] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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