Electron-rich triarylphosphines as nucleophilic catalysts for oxa-Michael reactions

• Susanne M. Fischer,
• Simon Renner,
• A. Daniel Boese and
• Christian Slugovc

Beilstein J. Org. Chem. 2021, 17, 1689–1697, doi:10.3762/bjoc.17.117

• ) after 24 h. To illustrate that the reaction does not stop after 24 h the conversions were re-checked after 21 d. After this time with TMTPP as the catalyst, conversions of 44% (3a), 92% (3b), 98% (3c), and 91% (3d) are obtained. No indications for aza-Michael reactions potentially leading to polyamide 3

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

• interaction with the reagents. As a result, several hollow fibres-immobilised catalysts have been prepared and applied in flow scenarios [112]. A titania-, zirconia- and silica-implanted polyamide-imide (PAI) hollow fibre was grafted with aminosilane functional groups in order to create a bifunctional

Valorisation of plastic waste via metal-catalysed depolymerisation

• Francesca Liguori,
• Carmen Moreno-Marrodán and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

Photocontrolled DNA minor groove interactions of imidazole/pyrrole polyamides

• Sabrina Müller,
• Jannik Paulus,
• Jochen Mattay,
• Heiko Ihmels,
• Veronica I. Dodero and
• Norbert Sewald

Beilstein J. Org. Chem. 2020, 16, 60–70, doi:10.3762/bjoc.16.8

• )phenyl)azophenylacetic acid, as the linker between two Im/Py polyamide strands. Only the (Z)-azobenzene-containing polyamides bound to the minor groove of double-stranded DNA hairpins. Photoisomerization was exemplarily evaluated by 1H NMR experiments, while minor groove binding of the (Z)-azobenzene

• promising strategy to obtain photoswitchable Im/Py hairpin polyamides capable of interacting with the dsDNA minor groove only in the Z-configuration. Keywords: azobenzene; DNA minor groove; N-methylimidazole; N-methylpyrrole; photoswitches; polyamide; Introduction The development of small chemical agents

• tethering of two antiparallel polyamide segments increases the sequence specificity and the affinity of the polyamides to their cognate dsDNA. Different linker strategies were used, with γ-aminobutyric acid (γ) being the most successful representative. The resulting hairpin polyamides bound with 100-fold

In search of visible-light photoresponsive peptide nucleic acids (PNAs) for reversible control of DNA hybridization

• Lei Zhang,
• Greta Linden and
• Olalla Vázquez

Beilstein J. Org. Chem. 2019, 15, 2500–2508, doi:10.3762/bjoc.15.243

• -penetrating wavelengths. Peptide nucleic acids (PNAs) [31] are synthetic nucleic acid analogues, in which nucleobases are linked to a repeating N-(2-aminoethyl)glycine polyamide backbone. The lack of phosphate groups provides them with both higher binding affinities to complementary DNA or RNA sequences and

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

• Py/Im polyamide 14 (Figure 6) that was able to bind preferentially the sequences 5′-WGGWWW-3′ and 5′ GGGWWW-3′ in the Nuclear factor κB sites, thereby reducing the expression of various NF-κB-driven genes including IL6 and IL8 [71]. Another structural analog of conjugate 11, conjugate 15 was

• ]. Gottesfeld et al. synthesized a series of Py/Im HP-polyamide–DNA alkylator (chlorambucil) (HP-Chl) conjugates in order to bind and alkylate within the HIV-1 promoter region, thereby blocking HIV-1 replication and screened them against human colon carcinoma cell lines [74][75]. It has been observed that

• site in the H4c promoter in treated cells, thereby inhibiting tumor growth in mice. Chenoweth and Dervan showed DNA structural distortion induced by an 8-ring cyclic Py/Im polyamide (conjugate 17) bound to the central 6 bp of the sequence d(5'-CCAGGCCTGG-3')2 by using a high resolution X-ray crystal

Theoretical simulation of the infrared signature of mechanically stressed polymer solids

• Matthew S. Sammon,
• Milan Ončák and
• Martin K. Beyer

Beilstein J. Org. Chem. 2017, 13, 1710–1716, doi:10.3762/bjoc.13.165

• uneven distribution of the external stress on individual polymer strands is accounted for by a convolution of simulated spectra with a realistic force distribution. N-Propylpropanamide and propyl propanoate are chosen as model molecules for polyamide and polyester, respectively. The effect of a specific

• spectroscopy; mechanical stress; polyamide; polyester; Introduction Mechanical stress on polymer solids leads to conformational changes, bond elongation and widening of bond angles on the molecular level [1][2][3][4]. If the local force on an individual polymer strand reaches values in the range of nN

• molecules for polyamide and polyester, respectively. To facilitate a comparison with future experimental studies, we convolute simulated infrared spectra with the exponential force distribution recently derived by Adhikari and Makarov for elastomeric polymer networks [81]. Results and Discussion Amide We

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• used in anticorrosive composites, polyester and polyamide threads, and lubricants, for the synthesis of tridecanedioic acid, and as a component of perfume formulations. Scheme 35 presents the synthesis of hydroxy-10H-acridin-9-one 117 starting from tetramethoxyanthracene 114 through the formation of

Application of Cu(I)-catalyzed azide–alkyne cycloaddition for the design and synthesis of sequence specific probes targeting double-stranded DNA

• Svetlana V. Vasilyeva,
• Vyacheslav V. Filichev and
• Alexandre S. Boutorine

Beilstein J. Org. Chem. 2016, 12, 1348–1360, doi:10.3762/bjoc.12.128

• synthesis of conjugates of pyrrole–imidazole polyamide minor groove binders (MGB) with fluorophores and with triplex-forming oligonucleotides (TFOs). Diverse bifunctional linkers were synthesized and used for the insertion of terminal azides or alkynes into TFOs and MGBs. The formation of stable triple

• ]. Besides natural and engineered peptides or proteins, two synthetic substances are known to recognize and bind dsDNA in a sequence-specific manner: triplex-forming oligonucleotides (TFOs) [4][5] and pyrrole–imidazole polyamide minor groove binders (MGBs) [6][7]. TFOs recognize polypurine stretches in

• transformations. So, this reaction is suitable for the synthesis of different biologically important conjugates including polyamide-TFO conjugates and fluorescent probes based on these components. Several methods avoiding the presence of cytotoxic copper ions have been also described [27][28][29]. Baskin et al

Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers

• Ivan Bassanini,
• Karl Hult and
• Sergio Riva

Beilstein J. Org. Chem. 2015, 11, 1583–1595, doi:10.3762/bjoc.11.174

• terminal hydroxy and one terminal amino moiety, were further reacted with diethyl sebacate to form high molecular weight poly(amide-co-ester)s with a repetitive pattern of amide and ester bonds (Figure 19) [74]. The problem of high molecular weights in lipase-catalyzed polyamide synthesis using

Photoswitchable precision glycooligomers and their lectin binding

• Daniela Ponader,
• Sinaida Igde,
• Marko Wehle,
• Katharina Märker,
• Mark Santer,
• David Bléger and
• Laura Hartmann

Beilstein J. Org. Chem. 2014, 10, 1603–1612, doi:10.3762/bjoc.10.166

• building blocks contain a free carboxy- and an Fmoc-protected amino group and thus can be coupled via standard peptide coupling protocols giving a polyamide backbone. Additionally, dimer building blocks can carry functional groups as side groups or in the main chain, thereby allowing for the conjugation of

Lanostane- and cycloartane-type triterpenoids from Abies balsamea oleoresin

• Serge Lavoie,
• Charles Gauthier,
• Jean Legault,
• Sylvain Mercier,
• Vakhtang Mshvildadze and
• André Pichette

Beilstein J. Org. Chem. 2013, 9, 1333–1339, doi:10.3762/bjoc.9.150

• /EtOAc (100:0 → 93:7) and MeOH as eluent. Both hexanes/EtOAc 93:7 and MeOH fractions were combined and concentrated under reduced pressure. Purification of this extract using a combination of silica gel or polyamide column chromatography and reversed phase C18 HPLC resulted in the isolation of three new

Imidazole as a parent π-conjugated backbone in charge-transfer chromophores

• Jiří Kulhánek and
• Filip Bureš

Beilstein J. Org. Chem. 2012, 8, 25–49, doi:10.3762/bjoc.8.4

• . However, the achieved nonlinearities are still lower than those measured for previous polymeric systems, e.g., 119 and 126–128. Chromophores 67 and 68 attached to polyamide and polyester backbones by copolymerization with m-phenylenediamide (MPD) and isophthaloyl dichloride (IPC) as well as bis

Miniemulsion polymerization as a versatile tool for the synthesis of functionalized polymers

• Daniel Crespy and
• Katharina Landfester

Beilstein J. Org. Chem. 2010, 6, 1132–1148, doi:10.3762/bjoc.6.130

• hydrophilic, the polymerization had to be carried out in inverse miniemulsions. ε-Caprolactam-in-oil miniemulsions could not be stabilized efficiently in contrast to DMSO-in-oil miniemulsions. Thus, ε-caprolactam was dissolved in DMSO to build the dispersed phase and polyamide-6 nanoparticles could be

• nanoparticles prepared in inverse microemulsion [123]. The polyamide was identified by infrared spectroscopy. Polyimide nanoparticles could be synthesized in ionic liquids at temperatures up to 190 °C even although water is produced during the polycondensation as shown in Scheme 2 [15]. Here again, the reaction