Acceptor-influenced and donor-tuned base-promoted glycosylation

• Stephan Boettcher,
• Martin Matwiejuk and
• Joachim Thiem

Beilstein J. Org. Chem. 2012, 8, 413–420, doi:10.3762/bjoc.8.46

• apparatus. Optical rotations were obtained by using a Krüss Optronic P8000 polarimeter (589 nm, 25 °C). HRMS (ESI) were recorded with a Thermo Finnigan MAT 95XL mass spectrometer. MS (MALDI–TOF) were recorded with a Bruker Biflex II (positive reflection mode, matrix: 2,5-dihydroxybenzoic acid). Relative

• , 127.6, 127.6, 127.5 (Car), 104.2 (C-1’), 97.9 (C-1), 82.3 (C-3’), 79.4 (C-2’), 79.1 (C-2), 79.1 (C-5), 76.3 (C-4’), 75.0, 74.7, 73.2, 73.0 (-O-CH2-Ph), 72.6 (C-3), 70.6 (C-5’), 70.1 (C-4), 68.8 (C-6), 55.2 (-OCH3), 16.7 (C-6’) ppm; MALDI–TOF–MS (DHB, positive mode; m/z): [M + Na]+ calcd for C41H48O10Na

• ), 79.1 (C-2), 75.2, 74.7, 74.5, 73.5, 72.9 (-O-CH2-Ph), 73.5 (C-4), 74.6 (C-5), 74.2 (C-2’), 73.4 (C-4), 71.4 (C-5’), 69.3 (C-6), 68.7 (C-6’), 57.1 (-OCH3) ppm; MALDI–TOF–MS (DHB, positive mode; m/z): [M + Na]+ calcd for C48H54O11Na, 829.36; found, 830.1. Monobenzylated methyl α- and β-D-gluco- and

Synthesis of mesomeric betaine compounds with imidazolium-enolate structure

• Nina Gonsior,
• Fabian Mohr and
• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 390–397, doi:10.3762/bjoc.8.42

• ). However, the reaction with both monomer balance (a) and imbalance (b) only led to oligomeric compounds (7a,b), which were soluble in water and DMSO but insoluble in, e.g., CHCl3, acetone or toluene. MALDI-TOF mass spectroscopy revealed a maximum repeat unit of m = 3 with 1,4-bis(1H-imidazol-1-yl)butane

• -time-of-flight mass spectrometry (MALDI-TOF-MS) was performed on a Bruker Ultraflex TOF mass spectrometer. Ions formed with a pulsed nitrogen laser (25 Hz, 337 nm) were accelerated to 25 kV, with the molecular masses being recorded in the linear mode. 2,5-Dihydroxybenzoic acid (DBH) in acetonitrile

Binding of group 15 and group 16 oxides by a concave host containing an isophthalamide unit

• Jens Eckelmann,
• Vittorio Saggiomo,
• Svenja Fischmann and
• Ulrich Lüning

Beilstein J. Org. Chem. 2012, 8, 11–17, doi:10.3762/bjoc.8.2

• unit. Elemental analyses were carried out with a EuroEA 3000 Elemental Analyzer from Euro Vector. MALDI-TOF spectra were recorded with Bruker-Daltonics Biflex III. 4-Chloro-α-cyanocinnamic acid (Cl-CCA) was used as the matrix. 1H NMR experiments Each NMR tube was filled with 600 µL of a stock solution

• −1. EIMS (70 eV): m/z (% relative intensity) 656 (100) [M]+•; CIMS (isobutane): m/z (% relative intensity) 657 (30) [M + H]+; ESIMS (CHCl3): m/z (% relative intensity) 679 (100) [M + Na]+, 657 (75) [M + H]+; MS (MALDI-TOF, Cl-CCA): m/z 695 [M + K]+, 679 [M + Na]+, 656 [M]+; HRMS calcd for C40H52N2O6

• (d, 252-C), 116.1 (s, 12,122-C), 105.4 (d, 14,6,124,6-C), 69.5 (t, OCH2), 35.3 (s, C(CH3)3), 31.2 (q, CH3), 30.7 (t, OCH2CH2), 24.9 (t, O(CH2)2CH2); The C=O signal was too weak to be detected in this 13C spectrum. MS (MALDI-TOF, Cl-CCA): m/z 676 [M + Na]+, 654 [M + H]+. Bi-macrocyclic concave host 1

Sexithiophenes as efficient luminescence quenchers of quantum dots

• Christopher R. Mason,
• Yang Li,
• Paul O’Brien,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2011, 7, 1722–1731, doi:10.3762/bjoc.7.202

• ), 7.20 (dd, J = 0.8 and 3.9, 2H), 7.17 (d, J = 3.5, 1H), 7.08 (m, 2H), 6.80 (d, J = 3.7, 1H), 3.36 (s, 8H), 2.86 (t, J = 7.7, 2H), 1.74 (q, 2H), 1.37 (m, 6H), 0.94 (t, J = 6.9, 3H); MS (MALDI-TOF) m/z: 838 (M+, 100%); FTIR (KBr) ν/cm−1: 2924, 2855, 1634, 1266, 1161, 1040; Anal. calcd for C34H29BrS10: C

• , toluene) and then precipitation to afford 7b as a red solid (0.23 g, 20%); mp 195 °C (by DSC); 1H NMR (CDCl3) δ 7.26 (m, 2H), 7.20 (d, J = 4.0, 2H), 7.15 (d, J = 3.5, 1H), 7.08 (m, 2H), 6.80 (d, J = 3.5, 1H), 3.36 (s, 8H), 2.55 (s, 3H); MS (MALDI-TOF) m/z: 769 (M+, 68%), 767 (M+, 100%); FTIR (KBr) ν/cm−1

Highly efficient cyclosarin degradation mediated by a β-cyclodextrin derivative containing an oxime-derived substituent

• Michael Zengerle,
• Florian Brandhuber,
• Christian Schneider,
• Franz Worek,
• Georg Reiter and
• Stefan Kubik

Beilstein J. Org. Chem. 2011, 7, 1543–1554, doi:10.3762/bjoc.7.182

• 600, Bruker DPX 400; MALDI-TOF-MS, Bruker Ultraflex TOF/TOF; ESI–MS, Bruker Esquire 3000; IR, FT-IR System Spectrum BX, Perkin-Elmer; elemental analysis, Elementar vario Micro cube. All chemicals, unless other stated, are commercially available and were used without further purification. Cyclosarin

Stereogenic boron in 2-amino-1,1-diphenylethanol-based boronate–imine and amine complexes

• Sebastian Schlecht,
• Walter Frank and
• Manfred Braun

Beilstein J. Org. Chem. 2011, 7, 615–621, doi:10.3762/bjoc.7.72

• (EI, 70 eV). High resolution mass spectra were carried out on Bruker FT-ICR APEX III (7.0 T) (MALDI) at the University of Bielefeld. Column chromatography was performed with Fluka silica gel 60 (230–400 mesh) and thin layer chromatography was carried out on Merck TLC Silicagel 60 F254 aluminium sheets

Photoinduced homolytic C–H activation in N-(4-homoadamantyl)phthalimide

• Nikola Cindro,
• Margareta Horvat,
• Kata Mlinarić-Majerski,
• Axel G. Griesbeck and
• Nikola Basarić

Beilstein J. Org. Chem. 2011, 7, 270–277, doi:10.3762/bjoc.7.36

• Applied Biosystems 4800 Plus MALDI TOF/TOF instrument. Melting points were obtained using an Original Kofler apparatus and are uncorrected. IR spectra were recorded on Perkin Elmer M-297 and ABB Bomem M-102 spectrophotometers. Solvents were purified by distillation. 4-Homoadamantanone (3) was prepared in

• ), 39.56 (d, C-3), 36.64 (t, C-5), 35.58 (t, C-11), 33.99 (t, C-7 or C-9), 31.53 (t, C-7 or C-9), 29.44 (d, C-1), 27.18 (d, C-6), 27.17 (d, C-8); IR (KBr) ν/cm−1 2910, 2850, 1765, 1707, 1375, 1350, 1323, 1114, 1084, 1070, 710; HRMS (MALDI), calculated for C19H22NO2 296.1645, observed 296.1644. General

• ), 64.31 (d, C-19), 48.19 (d, C-10), 42.21 (d, C-11), 40.94 (t, C-18), 40.38 (t, C-20), 35.62 (t, C-14), 32.69 (t, C-16), 31.17 (d, C-13), 30.62 (t, C-12), 27.93 (d, C-15), 26.89 (d, C-17); IR (KBr) ν/cm−1 3300, 2980, 2902, 1694, 1605, 1464, 1433, 1338, 1320, 1297, 1231, 1125, 1053; HRMS (MALDI

Amphiphilic dendritic peptides: Synthesis and behavior as an organogelator and liquid crystal

• Baoxiang Gao,
• Hongxia Li,
• Defang Xia,
• Sufang Sun and
• Xinwu Ba

Beilstein J. Org. Chem. 2011, 7, 198–203, doi:10.3762/bjoc.7.26

• -deprotected intermediate to the C-deprotected G1, prepared by hydrogenolysis of the benzylated peptide. 1H NMR, MALDI-TOF mass spectrometry, and elemental analyses were used to verify the structure and purity of the amphiphilic dendritic peptides. Investigation of gelation All amphiphilic dendritic peptides

• CDCl3 with tetramethylsilane as internal standard unless indicated otherwise. Mass spectra were carried out using MALDI-TOF/TOF matrix assisted laser desorption ionization mass spectrometry with Autoflex III Smartbeam (Bruker Daltonics Inc). Differential scanning calorimetry (DSC) was carried out with a

• (m, 36H), 0.88 (t, J = 7.1 Hz, 6H). Anal. Calcd for C36H61NO6: C, 71.60; H, 10.18; N, 2.32. found: C, 71.83; H, 10.02; N, 2.01. m/z [MALDI–TOF]: 604.7 (M + H+). G2: 1.335 g N-carbobenzyloxy-L-aspartic acid (5 mmol) was dissolved in 60 mL of DCM, 2.880 g EDCI (15 mmol) was added, and the mixture

An easy assembled fluorescent sensor for dicarboxylates and acidic amino acids

• Xiao-bo Zhou,
• Yuk-Wang Yip,
• Wing-Hong Chan and
• Albert W. M. Lee

Beilstein J. Org. Chem. 2011, 7, 75–81, doi:10.3762/bjoc.7.11

• and 13C NMR spectra were recorded on a Bruker Avance-III spectrometer (at 400 and 100 MHz, respectively) in DMSO-d6 or CDCl3. High resolution mass spectra were recorded on a Bruker Autoflex mass spectrometer (MALDI TOF). Fluorescent emission spectra were taken on a Perkin Elmer LS 50B luminescence

• , 127.51, 128.27, 128.92, 129.39, 129.45, 129.87, 130.03, 130.97, 133.00, 136.19, 136.61, 137.68, 181.84. MALDI TOF HRMS: calcd for C28H27N3S2 [M+H]+ 470.1719; found 470.1700. Synthesis of Sensor 1: Compound 4 (70 mg, 0.15 mmol) and (+)-α-ethylphenylamine (24 mg, 0.2 mmol) were dissolved in dry DMSO (10 mL

• , 129.39, 129.45, 129.87, 130.03, 130.97, 133.00, 136.19, 136.61, 137.68, 181.84. MALDI TOF HRMS: calcd for C36H38N4S2 [M+H]+ 591.2583; found 591.2596. Synthesis of sensor 2: Compound 4 (70 mg, 0.15mmol ) and (S)-phenylalaninol (30 mg, 0.2 mmol) were dissolved in dry DMSO (10 mL) and the mixture was

About the activity and selectivity of less well-known metathesis catalysts during ADMET polymerizations

• Hatice Mutlu,
• Lucas Montero de Espinosa,
• Oĝuz Türünç and
• Michael A. R. Meier

Beilstein J. Org. Chem. 2010, 6, 1149–1158, doi:10.3762/bjoc.6.131

• further complemented and confirmed by MALDI analysis of an amino acid polymer synthesized with Grubbs 2nd generation catalyst [29]. Recently, a detailed study of temperature, catalyst, and polymerization condition dependent isomerization side reactions that occur during ADMET polymerizations was reported

Self-assembly and semiconductivity of an oligothiophene supergelator

• Pampa Pratihar,
• Suhrit Ghosh,
• Vladimir Stepanenko,
• Sameer Patwardhan,
• Ferdinand C. Grozema,
• Laurens D. A. Siebbeles and
• Frank Würthner

Beilstein J. Org. Chem. 2010, 6, 1070–1078, doi:10.3762/bjoc.6.122

• ), 3.14–3.10 (m, 4H),1.81–1.25 (m, 120H), 0.89–0.85 (m, 18H); UV-vis (CH2Cl2): λmax (ε) = 262 nm (1.76 × 104 M−1 cm−1), 405 nm (2.90 × 104 M−1 cm−1); HRMS (ESI): m/z calcd for C106H172N2Na1O8S4 [M + Na]+ :1752.1881; found: 1752.1920; MS (MALDI) m/z calcd for C106H172N2O8S4 [M + H]+ 1730.206, found

Redox-active tetrathiafulvalene and dithiolene compounds derived from allylic 1,4-diol rearrangement products of disubstituted 1,3-dithiole derivatives

• Filipe Vilela,
• Peter J. Skabara,
• Christopher R. Mason,
• Thomas D. J. Westgate,
• Asun Luquin,
• Simon J. Coles and
• Michael B. Hursthouse

Beilstein J. Org. Chem. 2010, 6, 1002–1014, doi:10.3762/bjoc.6.113

• .); MALDI-TOF MS: 580; Accurate Mass calculated for C26H12S8 579.8699 found 579.8707; 1H NMR (major isomer, 400 MHz, CDCl3) δH (ppm): 7.71 (1H, d, J = 0.7 Hz), 7.49 (1H, dd, J = 5.1 and 1.1 Hz), 7.34 (1H, d, J = 5.5 Hz), 7.26 (1H, dd, J = 3.5 and 1.1 Hz), 7.23 (1H, dd, J = 5.5 and 0.7 Hz), 7.19 (1H, dd, J

Donor-acceptor substituted phenylethynyltriphenylenes – excited state intramolecular charge transfer, solvatochromic absorption and fluorescence emission

• Ritesh Nandy and
• Sethuraman Sankararaman

Beilstein J. Org. Chem. 2010, 6, 992–1001, doi:10.3762/bjoc.6.112

• , 129.9, 129.1, 128.9, 127.7, 127.6, 127.5, 127.4, 127.3, 123.5, 123.4, 123.3, 120.6, 84.1, 77.9 ppm; MALDI-TOF MS m/z (%) 252 (72) [M+], 253 (100) [M+ + 1], 254 (22) [M+ + 2]; Anal. calcd. for C20H12 C, 95.23; H, 4.75. Found C, 95.04, H 4.60. General procedure for the synthesis of 1a–e. 1a–e were

• , 128.5 (q, 3JC-F = 3.75 Hz), 127.7, 127.6, 127.41, 127.39, 127.0, 124.87 (q, 3JC-F = 3.75 Hz), 124.3, 123.5, 123.4, 123.3, 122.7, 121.1, 91.4, 88.6 ppm; MALDI-TOF MS C27H15F3 m/z (%) 396 (100) [M+], 397 (84) [M+ + 1], 398 (22) [M+ + 2]. 4-(2-Triphenylenylethynyl)benzonitrile (1c). The crude product was

• , 115.4, 113.5, 113.5, 90.6, 88.2, 69.4, 69.2, 31.9, 29.7, 29.6, 29.4, 29.36, 29.30, 29.26, 26.1, 22.7, 14.1 ppm; MALDI-TOF MS: m/z (%) 640 (100) [M+], 641 (49) [M+ + 1], 642 (9) [M+ + 2]. N,N-Dimethyl-4-(2-triphenylenylethynyl)aniline (1g). The crude product was purified by column chromatography with a

Towards racemizable chiral organogelators

• Jian Bin Lin,
• Debarshi Dasgupta,
• Seda Cantekin and
• Albertus P. H. J. Schenning

Beilstein J. Org. Chem. 2010, 6, 960–965, doi:10.3762/bjoc.6.107

• Varian Mercury NMR Spectrometer. IR spectra were measured on a Perkin Elmer 1600 FT-IR. MALDI-TOF MS spectra were measured on a Perseptive DE Voyager Mass Spectrometer with α-cyano-4-hydroxycinnamic acid as the matrix. Synthesis Phenylglycinamide R-2, S-2: The ester salt R-1, S-1 (5.04 g, 25 mmol) was

• ): 7.43 (m, 2H, ArH); 7.31 (m, 3H, ArH); 4.84 (br, 4H, NH2); 4.44 (s, 1H, COCH). MALDI-TOF MS (calc MW = 150.08, C8H10N2O): 150.97 [M + H]+. IR ν (cm−1): 3339; 3073; 1660; 1454; 1405; 1271; 869; 699. R-3, S-3: To a solution of 3,4-didodecyloxybenzaldehyde (237 mg, 0.5 mmol) in toluene, was added compound

• ) ; 1.83 (m, 32H, CH2) ; 1.83 (m, 6H, CH3). 13C NMR (CDCl3, 100 MHz): 199.20; 174.34; 162.90; 152.33; 149.32; 144.98; 139.45; 128.65; 128.43; 127.83; 127.25; 123.52; 112.46; 111.78; 69.35; 69.07; 31.90; 29.62; 29.42; 29.34; 29.25; 29.08; 26.03; 25.96; 22.66; 14.09. MALDI-TOF MS (calc MW = 606.48

Formation of epoxide-amine oligo-adducts as OH-functionalized initiators for the ring-opening polymerization of ε-caprolactone

• Julia Theis and
• Helmut Ritter

Beilstein J. Org. Chem. 2010, 6, 938–944, doi:10.3762/bjoc.6.105

• reaction was carried out under simultaneous cooling with 5 psi of compressed air. The obtained epoxide-amine addition product 4 was characterized by 13C NMR, Fourier transform infrared (FT-IR) spectroscopy and matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) mass spectrometry. The

• two very weak signals, which were difficult to discern, at 2.81 and 2.66 ppm, corresponding to the CH2 of the epoxide group. MALDI-TOF MS measurements (Figure 2) definitely indicated the formation of an oligomer homologous series of epoxide-amine addition products of 1 and 3. The amino alcohol

• the midpoint method. The melting point (Tm) values are reported as the average peak maxima of the second and the third heating cycle. Matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) was performed on a Bruker Ultraflex TOF mass spectrometer. Ions formed with

Synthesis and crystal structures of multifunctional tosylates as basis for star-shaped poly(2-ethyl-2-oxazoline)s

• Richard Hoogenboom,
• Martin W. M. Fijten,
• Guido Kickelbick and
• Ulrich S. Schubert

Beilstein J. Org. Chem. 2010, 6, 773–783, doi:10.3762/bjoc.6.96

• . 1H and 13C NMR spectroscopy and elemental analysis, the chemical structures of the TetraTos and HexaTos were verified by MALDI-TOF MS, revealing only the desired mass peak corresponding to full tosylation (Figure 2). The absence of residual hydroxyl groups is of major importance for the use of these

• compared to the previously discussed multi-tosylates, partly counteracting the advantages of multi-tosylate initiators compared to multi-halides and multi-triflates. Figure 8 depicts the MALDI-TOF MS spectrum of the porphyrin initiator TetraTos-B. The formation of TetraTos-B (mass 1582) and a minor

• value results from diffusion of the organic compound in the column since it is almost monodisperse (see MALDI in Figure 8). The star-PEtOx could not be characterized with the RI-detector due to the combination of a positive signal of the polymer and a negative signal of the porphyrin. However, detection

En route to photoaffinity labeling of the bacterial lectin FimH

• Thisbe K. Lindhorst,
• Michaela Märten,
• Andreas Fuchs and
• Stefan D. Knight

Beilstein J. Org. Chem. 2010, 6, 810–822, doi:10.3762/bjoc.6.91

• spectrometry For mass spectrometric analyses of the photo-crosslinked products, a Bruker Biflex III instrument (MALDI-TOF-MS, Prof. Th. K. Lindhorst, CAU), or a Bruker Biflex II instrument (ESI-FT-ICR-MS/MS, group of PD Dr. B. Lindner at the Research Center Borstel), or the 4700 Proteomics Analyzer mass

• spectrometer (Applied Biosystems MALDI-TOF/TOF-MS, group of Prof. M. Leippe, CAU) were used. Mass spectra were acquired using standard experimental sequences as provided by the manufacturer. Analysis of photo-crosslinking with angiotensin II is exemplified with diazirine 2 and presented in Figure 4. FimH

• were based on 2D experiments (COSY, HSQC, HMBC or NOESY). IR spectra were taken with a Perkin Elmer FT IR Paragon 1000 (KBr). Optical rotations were measured with a Perkin-Elmer polarimeter (22 °C, 589 nm, length of cuvette: 1 dm). For MS analysis of the synthetic products MALDI-TOF mass spectra were

A bivalent glycopeptide to target two putative carbohydrate binding sites on FimH

• Thisbe K. Lindhorst,
• Kathrin Bruegge,
• Andreas Fuchs and
• Oliver Sperling

Beilstein J. Org. Chem. 2010, 6, 801–809, doi:10.3762/bjoc.6.90

• , length of cell: 1 dm). ESI-MS measurements were recorded on a Mariner ESI-TOF 5280 (Applied Biosystems) instrument and MALDI-MS measurements on a MALDI-TOF-MS-Biflex III (Bruker) instrument. 2-[N-(Nω-tert-Butyloxycarbonyl-pentaglycyl)]-amidoethyl α-D-mannopyranoside (7) Glyc5Boc (300 mg, 0.74 mmol) was

• = 175.96 (NH-C(O)O), 174.60, 174.36, 173.74 (5 NH-CH2-CO), 101.98 (C-1), 84.15 (C(CH3)3), 75.11 (C-5), 72.80 (C-3), 72.32 (C-2), 69.10 (C-4), 68.02 (manOCH2CH2N), 63.25 (C-6), 45.82 (manOCH2CH2N), 44.81 (4 NH-CH2-CO), 41.27 (NH-CH2-CO), 29.89 (C(CH3)3) ppm; MALDI-TOF-MS: m/z 631.1, [M + Na]+ (631.3 calcd

• , H-5, H-6a, H-6b, manOCH2CH2N, NH-CH2-CO) ppm; MALDI-TOF-MS: m/z 531.1 [M + Na]+ (531.2 calcd. for the free amine C18H32N6O11 + Na). 2-Azidoethyl 2,4-di-O-benzoyl-3,6-di-O-(2,3,4,6-tetra-O-benzoyl-α-D-mannopyranosyl)-α-D-mannopyranoside (13) The 2,4-di-O-benzoyl-protected mannoside 11 [28] (250 mg

Novel multi-responsive P2VP-block-PNIPAAm block copolymers via nitroxide-mediated radical polymerization

• Cathrin Corten,
• Katja Kretschmer and
• Dirk Kuckling

Beilstein J. Org. Chem. 2010, 6, 756–765, doi:10.3762/bjoc.6.89

• nitroxide terminated polymers were characterized by nuclear magnetic resonance (NMR) spectroscopy, size exclusion chromatography (SEC) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Thermal properties were investigated by the differential scanning

• having higher molecular weights. By performing NMRP on 2VP, the resulting polymer should possess defined end groups (Scheme 1). In order to analyze the polymer structure MALDI-TOF MS was employed. The spectra of samples obtained from the polymerization at 110 °C with a [initiator/monomer] ratio of 1:140

• stopped after 2, 4, 6 and 8 h are depicted in Figure 4. All distributions of the polymers exhibited differences between the m/z-peaks in the MALDI-TOF spectra that can be attributed to the weight of the 2VP monomer unit. In contrast to the molecular weight data obtained by SEC analysis, the molecular

Synthesis, spectral characterization, electron microscopic study and thermogravimetric analysis of a phosphorus containing dendrimer with diphenylsilanediol as core unit

• E. Dadapeer,
• B. Hari Babu,
• C. Suresh Reddy and
• Naga Raju Charmarthi

Beilstein J. Org. Chem. 2010, 6, 726–731, doi:10.3762/bjoc.6.85

• groups. The structures of the intermediate compounds were confirmed by IR, GCMS and 31P NMR. The final compound was characterized by 1H, 13C, 31P NMR, MALDI-TOF MS and CHN analysis. Scanning electron microscopic and thermogravimetric analysis/differential scanning calorimetric studies were also performed

• phosphorus atoms. The mass spectral properties of the final dendrimer G6 was studied by Matrix Assisted Laser Desorption/Ionisation (MALDI) mass spectrometry. As expected, the mass obtained from the MALDI measurements was in good agreement with the calculated value (Table 1). The surface topography of the

• water; for the 50% decomposition of the compound the heat change is endothermic at around 225 °C. The small endothermic peaks are due to decomposition of branches. SEM image of G6. TGA and DTA curve of G6. Synthesis of G5. Synthesis of dendritic macromolecule G6. Mass data of G6 obtained from MALDI

Calix[4]arene-click-cyclodextrin and supramolecular structures with watersoluble NIPAAM-copolymers bearing adamantyl units: “Rings on ring on chain”

• Bernd Garska,
• Monir Tabatabai and
• Helmut Ritter

Beilstein J. Org. Chem. 2010, 6, 784–788, doi:10.3762/bjoc.6.83

• 5,11,17,23-tetra-tert-butyl-25,27-dipropargylether-26,28-hydroxy-calix[4]arene (calix[4]arene-dipropargylether) (2) onto 6I-azido-6I-deoxycyclomaltoheptaose (3) under microwave assisted conditions. The coupling was proven by MALDI-TOF mass spectrometry, 1H NMR and IR-spectroscopy. The pH dependent

• NMR spectrum of the successful cycloaddition of 2 and 3 indicates that the di-substituted calix[4]arene 4 was the major product along with a little amount of the mono-substituted compound. In addition, the MALDI-TOF-MS clearly confirmed the existence of the covalently combined rings (4) with a

• desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) was performed on a Bruker Ultraflex TOF mass spectrometer. Ions formed with a pulsed nitrogen laser (25 Hz, 337 nm) were accelerated to 25 kV, the molecular masses being recorded in linear mode. 2-(4-Hydroxyphenylazo)benzoic eacid (HABA

Synthesis of 6-PEtN-α-D-GalpNAc-(1–>6)-β-D-Galp-(1–>4)-β-D-GlcpNAc-(1–>3)-β-D-Galp-(1–>4)-β-D-Glcp, a Haemophilus influenzae lipopolysacharide structure, and biotin and protein conjugates thereof

• Andreas Sundgren,
• Martina Lahmann and
• Stefan Oscarson

Beilstein J. Org. Chem. 2010, 6, 704–708, doi:10.3762/bjoc.6.80

• the acetamido carbonyl oxygen also partly behaved as a nucleophile and gave a pseudohexasaccharide acetimidate side product according to MALDI-TOF and NMR. Similar side products have earlier been described [25][26][27][28]. Mild acid treatment of the glycosylation mixture prior to purification led to

• of 23, from which the Boc-group was removed by acid hydrolysis to afford derivative 24. Protein conjugations were performed by reaction of 24 (20 equiv) with human serum albumin (HSA). Compound 20 was similarly activated with dimethyl squarate and conjugated to HSA. MALDI-TOF MS of the HSA-conjugates

Synthesis, electronic properties and self-assembly on Au{111} of thiolated (oligo)phenothiazines

• Adam W. Franz,
• Svetlana Stoycheva,
• Michael Himmelhaus and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2010, 6, No. 72, doi:10.3762/bjoc.6.72

• ), 125.7 (CH), 126.9 (Cquat), 127.6 (CH), 129.7 (CH), 130.2 (Cquat), 134.6 (Cquat), 144.7 (Cquat). MS (MALDI-TOF) m/z (%): 1206.3 (M+, 100), 1126.4 (M+ − Br), 1121.2 (M+ − C6H13, 6), 1041.2 (M+ − Br − C6H13, 6). MS (FAB+) m/z (%): 1206.2 (M+, 100), 1121.1 (M+ − C6H13, 45), 1037.0 (M+ − 2C6H13, 10), 951.0

• ), 146.8 (Cquat), 194.9 (Cquat). MS (MALDI-TOF) m/z (%): 919.4 (M+, 100), 877.4 (M+ − COCH3, 4). IR (KBr): ν = 2954, 2928, 2855, 1700, 1635, 1458, 1416, 1379, 1241, 1193, 873, 807, 747 cm−1. UV–vis (CH2Cl2): λmax (ε) = 280 (101000), 326 (38100), 364 nm (31400). Anal. calcd. for C56H61N3OS4: C, 73.08; H

• (CH), 132.8 (CH), 133.5 (CH), 134.3 (CH), 140.1 (Cquat), 140.8 (Cquat), 146.3 (Cquat), 148.1 (Cquat), 194.9 (Cquat). MS (MALDI-TOF) m/z: 1200.5 (M+), 1158.5 (M+ − COCH3), 1126.5 (M+ − SCOCH3), 1116.4 (M+ − C6H13). IR (KBr): ν = 2955, 2928, 2854, 1706, 1634, 1604, 1575, 1459, 1415, 1379, 1333, 1241

Free radical homopolymerization of a vinylferrocene/cyclodextrin complex in water

• Helmut Ritter,
• Beate E. Mondrzik,
• Matthias Rehahn and
• Markus Gallei

Beilstein J. Org. Chem. 2010, 6, No. 60, doi:10.3762/bjoc.6.60

• MALDI-TOF which indicated a mass of 6172.7 [M+Na]+. Very recently a paper was published, reporting the expected LCST properties of the copolymer consisting of N-allylferrocenecarboxamide and N-isopropylacrylamide (poly(NiPAAM/FCN)) [26]. However, in this instance the copolymer was prepared by a

• -H), 3.86 (20 H, 4-H), 4.25–3.96 (9 H, 7-H), 4.71–5.20 (21H, 10-H), 6.18 (1H, 6-H), 7.20 (20H, 5-H); MALDI-TOF 7: m/z 1.6 × 104. Dynamic light scattering of methyl-β-CD 2 (solid line), vinylferrocene 1 complexed with methyl-β-CD (dashed line) and complexed polyvinylferrocene 3 (dotted line). The

Synthesis and crossover reaction of TEMPO containing block copolymer via ROMP

• Olubummo Adekunle,
• Susanne Tanner and
• Wolfgang H. Binder

Beilstein J. Org. Chem. 2010, 6, No. 59, doi:10.3762/bjoc.6.59

• using matrix assisted laser desorption ionization mass spectroscopy (MALDI-TOF) and nuclear magnetic resonance (NMR), respectively. MALDI showed that there was a complete crossover reaction after the addition of 25 equivalents of the second monomer. NMR investigation showed that U3 gave a faster rate of

• polymerization in comparison to U1. The synthesis of block copolymers with molecular weights up to Mn = 31 000 g/mol with low polydispersities (Mw/Mn = 1.2) is reported. Keywords: block copolymer (BCP); crossover reaction; MALDI; NEOLYST™; ROMP; Introduction Block copolymers are macromolecules composed of

• -“click”-chemistry [14][15][16][17], the crossover reaction of more complex monomers remains the crucial factor in achieving defined BCP’s with low polydispersities. In a recent example, the crossover reaction of various monomers with the Grubbs’ type catalysts G1–G3 was studied in detail via MALDI mass