Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• structures (Figure S4), experimental and calculated geometric parameters (Tables S1 and S2) and vibrational assignments (Tables S3 and S4), 13C, COSY, HMBC and HSQC spectra (Figures S5–S12) and the full NMR characterization (Table S5) for both hydrazones reported herein. Hydrolytic stability of hdz-NO2 at pH

Tuning the stability of alkoxyisopropyl protection groups

• Zehong Liang,
• Henna Koivikko,
• Mikko Oivanen and
• Petri Heinonen

Beilstein J. Org. Chem. 2019, 15, 746–751, doi:10.3762/bjoc.15.70

• conditions used to remove benzoyl protecting groups and toward tetrabutylammonium fluoride used to remove the tert-butyldimethylsilyl (TBS) protection. The products could be purified by silica gel column chromatography without degradation when 0.5% triethylamine was added to the eluent. Hydrolytic stability

• of acetal synthesis. We also prepared the corresponding derivative 8b of thymidine and studied its hydrolytic stability separately. This is of some interest for discussion of mechanisms of acetal hydrolysis, since the vinyl ether intermediate 8b could probably be formed on the pathway shown in the

• advantage of MIP-protection. On the other hand, the 2-cyclohexyloxypropan-2-yl substituent gives the benefit of better solubility in organic solvents. Conclusion The hydrolytic stability of five different “acetone-based” acetal protecting groups, i.e., 2-alkoxypropan-2-yl groups introduced at the 5’- and 3

Silanediol versus chlorosilanol: hydrolyses and hydrogen-bonding catalyses with fenchole-based silanes

• Falco Fox,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2019, 15, 167–186, doi:10.3762/bjoc.15.17

• ) and BIFOXSiCl(OH) (8) are described. The hydrolytic stability of dichlorosilane 7 is investigated in a kinetics study and is compared to analogue dichlorosilanes, i.e., 13 and 14 (Scheme 4). UV–vis titration experiments and catalyses are carried out with chlorosilanol 8 and silanediol 9, to assess

Synthetic avenues towards a tetrasaccharide related to Streptococcus pneumonia of serotype 6A

• Aritra Chaudhury,
• Mana Mohan Mukherjee and
• Rina Ghosh

Beilstein J. Org. Chem. 2018, 14, 1095–1102, doi:10.3762/bjoc.14.95

• SPn 6A in multicomponent vaccines like Pneumovax® has been recognized [15]. The low hydrolytic stability of the phosphodiester linkages in the clinical isolates of the SPn 6A polysaccharides poses a major drawback as it leads to low bioavailability [16]. Hence, the requirements of pure SPn 6A

Recent advances in synthetic approaches for medicinal chemistry of C-nucleosides

• Kartik Temburnikar and
• Katherine L. Seley-Radtke

Beilstein J. Org. Chem. 2018, 14, 772–785, doi:10.3762/bjoc.14.65

• feature (hetero)aryl aromatic groups such as 9-deazapurines, pyrimidines, pyridines and phenyl groups connected by a C–C bond to a sugar (or sugar mimic) as shown in Figure 4 [30][45][46][47][50][54][55][56][57]. The change in the nature of the glycosidic bond is accompanied by i) increased hydrolytic

• stability, ii) altered hydrogen bonding motifs, and iii) altered molecular recognition properties [25][29][37][58]. Because of these changes, C-nucleosides have been useful in the study of RNA and DNA processing enzymes, as well as drug design efforts and novel supramolecular structures [12][29][59

Hydrolysis, polarity, and conformational impact of C-terminal partially fluorinated ethyl esters in peptide models

• Vladimir Kubyshkin and
• Nediljko Budisa

Beilstein J. Org. Chem. 2017, 13, 2442–2457, doi:10.3762/bjoc.13.241

• used to model the effects of fluorination on the lipophilicity, hydrolytic stability and on conformational properties. The conformational impact of the 2,2-difluoromethyl ester on several neutral and charged oligopeptides was also investigated. Our results demonstrate that partially fluorinated esters

• undergo variable hydrolysis in biologically relevant buffers. The hydrolytic stability can be tailored over a broad pH range by varying the number of fluorine atoms in the ester moiety or by introducing adjacent charges in the peptide sequence. Keywords: conformation; ester bond; hydrolysis; peptides

• investigation of the impact of partial fluorination on target peptides. Of particular importance are investigations of the hydrolytic stability of the partially fluorinated esters and the possible conformational impact on the peptide. Thus, we herein report results from studies of N-acetylproline esters, which

One-pot synthesis of block-copolyrotaxanes through controlled rotaxa-polymerization

• Jessica Hilschmann,
• Gerhard Wenz and
• Gergely Kali

Beilstein J. Org. Chem. 2017, 13, 1310–1315, doi:10.3762/bjoc.13.127

• allows synthesis of symmetrical triblock-copolymers in two steps. Other benefits of trithiocarbonate CTAs are the good hydrolytic stability [38], as well as their approved application in controlled isoprene polymerization [39][40]. Randomly methylated β-CD (RAMEB) was chosen as the CD derivative for this

Highly reactive, liquid diacrylamides via synergistic combination of spatially arranged curing moieties

• Maximilian Maier,
• Magnus S. Schmidt,
• Markus Ringwald and
• Christoph P. Fik

Beilstein J. Org. Chem. 2017, 13, 372–383, doi:10.3762/bjoc.13.40

• (meth)acrylate-based compositions, however, is their susceptibility to premature hydrolysis when used in aqueous solutions, especially at pH values <2.5 [15][16]. One strategy to improve the hydrolytic stability is the oxygen-to-nitrogen substitution. The obtained class of (meth)acrylamides is of

Hydroxy-functionalized hyper-cross-linked ultra-microporous organic polymers for selective CO₂ capture at room temperature

• Partha Samanta,
• Priyanshu Chandra and
• Sujit K. Ghosh

Beilstein J. Org. Chem. 2016, 12, 1981–1986, doi:10.3762/bjoc.12.185

• ]. In terms of surface area, tuneable porosity and feasible host–guest interaction, MOFs have scored over other above mentioned porous materials [6]. But the less hydrolytic stability of metal-organic frameworks limits their real time application [7][8]. So the search for new materials having high

Synthesis and in vitro cytotoxicity of acetylated 3-fluoro, 4-fluoro and 3,4-difluoro analogs of D-glucosamine and D-galactosamine

• Štěpán Horník,
• Lucie Červenková Šťastná,
• Petra Cuřínová,
• Jan Sýkora,
• Kateřina Káňová,
• Roman Hrstka,
• Ivana Císařová,
• Martin Dračínský and
• Jindřich Karban

Beilstein J. Org. Chem. 2016, 12, 750–759, doi:10.3762/bjoc.12.75

• glycan and glycosaminoglycan biosynthesis [2][3], to inhibit amino sugars processing enzymes [4][5], to probe interactions of amino sugars with their target enzymes and lectins [6][7], or to increase the hydrolytic stability of the glycosidic bond in amino sugar glycosides [8][9]. For example, acetylated

Hexacoordinate Ru-based olefin metathesis catalysts with pH-responsive N-heterocyclic carbene (NHC) and N-donor ligands for ROMP reactions in non-aqueous, aqueous and emulsion conditions

• Shawna L. Balof,
• K. Owen Nix,
• Matthew S. Olliff,
• Sarah E. Roessler,
• Arpita Saha,
• Kevin B. Müller,
• Ulrich Behrens,
• Edward J. Valente and
• Hans-Jörg Schanz

Beilstein J. Org. Chem. 2015, 11, 1960–1972, doi:10.3762/bjoc.11.212

• develop water-soluble catalyst systems which can perform the task with high activity, substrate range and sufficient hydrolytic stability to access a variety of novel ROMP latexes. We now wish to report the synthesis of two new pH-responsive, Ru-based olefin metathesis catalysts, their ROMP and ring

Formulation development, stability and anticancer efficacy of core-shell cyclodextrin nanocapsules for oral chemotherapy with camptothecin

• Hale Ünal,
• Naile Öztürk and
• Erem Bilensoy

Beilstein J. Org. Chem. 2015, 11, 204–212, doi:10.3762/bjoc.11.22

• . The hydrolytic stability of CPT in nanocapsules was investigated in simulated gastric and intestinal fluids (SGF, SIF). Results: The mean particle sizes of both anionic and cationic CPT-loaded nanocapsules were in the range of 180–200 nm with polydispersity indices lower than 0.400 indicating

Synthesis of guanidinium–sulfonimide ion pairs: towards novel ionic liquid crystals

• Martin Butschies,
• Manuel M. Neidhardt,
• Markus Mansueto,
• Sabine Laschat and
• Stefan Tussetschläger

Beilstein J. Org. Chem. 2013, 9, 1093–1101, doi:10.3762/bjoc.9.121

• Seddon and Bruce [13]. Regarding ionic liquids, sulfonimides have been used in various ways. Particularly interesting is the symmetrical bistriflimide anion [14], which leads to desirable properties such as hydrolytic stability, low viscosity or low melting points in the ionic liquids [1][4][15][16][17

Discovery of practical production processes for arylsulfur pentafluorides and their higher homologues, bis- and tris(sulfur pentafluorides): Beginning of a new era of “super-trifluoromethyl” arene chemistry and its industry

• Teruo Umemoto,
• Lloyd M. Garrick and
• Norimichi Saito

Beilstein J. Org. Chem. 2012, 8, 461–471, doi:10.3762/bjoc.8.53

• , SF5 has high hydrolytic stability, which equals or exceeds CF3 [2]. These extraordinary properties render SF5 compounds highly attractive particularly in medicinal [5][6][7][8][9][10][11][12][13][14], agrochemical [15][16][17][18], and new material [19][20][21][22][23] chemistry and industry. However

Laterally substituted symmetric and nonsymmetric salicylideneimine-based bent-core mesogens

• Sonja Findeisen-Tandel,
• Wolfgang Weissflog,
• Ute Baumeister,
• Gerhard Pelzl,
• H. N. Shreenivasa Murthy and
• Channabasaveshwar V. Yelamaggad

Beilstein J. Org. Chem. 2012, 8, 129–154, doi:10.3762/bjoc.8.15

• group in ortho-position to the CH=N (azomethine) unit not only enhances the photochemical and hydrolytic stability due to intramolecular H-bonding, but also increases the clearing temperature of liquid crystals. Therefore, the introduction of salicylideneimine fragment(s) in the LC molecular

The C–F bond as a conformational tool in organic and biological chemistry

• Luke Hunter

Beilstein J. Org. Chem. 2010, 6, No. 38, doi:10.3762/bjoc.6.38

• use is hampered by low hydrolytic stability. This problem can be overcome by incorporating a fluorine atom in the C2′ position (23 and 24, Figure 4). The enhanced acid-stability of 23 and 24 is due to the fluorine atom inductively destabilising the glycosyl carbonium ion hydrolytic intermediate

Synthesis of bis(3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoyl)(phenyl)phosphine oxide – a tailor-made photoinitiator for dental adhesives

• Norbert Moszner,
• Iris Lamparth,
• Jörg Angermann,
• Urs Karl Fischer,
• Frank Zeuner,
• Thorsten Bock,
• Robert Liska and
• Volker Rheinberger

Beilstein J. Org. Chem. 2010, 6, No. 26, doi:10.3762/bjoc.6.26

• -butyl]acrylate [3] or 1,3-bis(methacrylamido)propane-2-yl dihydrogen phosphate (BMAMHP) [4], which show improved hydrolytic stability under acidic aqueous conditions. The visible-light (VL) photoinitiators (PIs) in current SEAs are based on mixtures of camphorquinone (CQ) and tertiary amines (A) [5

N-alkyl-N-(phosphonoethyl) substituted (meth)acrylamides – new adhesive monomers for self-etching self-priming one part dental adhesive

• Joachim E. Klee and
• Uwe Lehmann

Beilstein J. Org. Chem. 2009, 5, No. 72, doi:10.3762/bjoc.5.72

• spectroscopy as well as refractive index and viscosity. The phosphonoethyl substituted (meth)acrylamide monomers show improved hydrolytic stability compared to carboxylic esters. The highest stability was found for the phosphonoethyl substituted acrylamide monomers. Acrylamides have a larger polymerization

• substrates, namely 15.3 ± 3.4 MPa to enamel and 18.5 ± 2.3 MPa to dentin. Keywords: adhesion to enamel and dentin; hydrolytic stability; N-alkyl-N-(phosphonoethyl) substituted (meth)acrylamides; polymerization enthalpy; REM investigation; Introduction In the past decades dental adhesives have been employed

• stability of conventional polymerizable acidic ester monomers. The low hydrolytic stability arises from the hydrolysis of acidic and adhesive (meth)acrylester monomers in water or water/solvent mixtures. Therefore, the known acidic and adhesive monomers must be stored water-free and mixed with the aqueous