An alternative C–P cross-coupling route for the synthesis of novel V-shaped aryldiphosphonic acids

• Stephen J. I. Shearan,
• Enrico Andreoli and
• Marco Taddei

Beilstein J. Org. Chem. 2022, 18, 1518–1523, doi:10.3762/bjoc.18.160

• Abstract The synthesis of phosphonate esters is a topic of interest for various fields, including the preparation of phosphonic acids to be employed as organic linkers for the construction of metal phosphonate materials. We report an alternative method that requires no solvent and involves a different

• . Phosphonates can also be employed as organic linkers in combination with metal ions to afford coordination polymers and metal-organic frameworks (MOFs), or more aptly, metal phosphonate frameworks [19][20]. One of the main challenges in the synthesis of metal phosphonates is that the linkers are rarely

• organic linkers for the synthesis of open framework metal phosphonate materials. The proposed protocol does not require a solvent, while featuring reaction times and yields comparable, if not better, to those of most procedures commonly employed in the literature. Results and Discussion The goal of this

Naphthalimide-phenothiazine dyads: effect of conformational flexibility and matching of the energy of the charge-transfer state and the localized triplet excited state on the thermally activated delayed fluorescence

• Kaiyue Ye,
• Liyuan Cao,
• Davita M. E. van Raamsdonk,
• Zhijia Wang,
• Jianzhang Zhao,
• Daniel Escudero and
• Denis Jacquemin

Beilstein J. Org. Chem. 2022, 18, 1435–1453, doi:10.3762/bjoc.18.149

• above, various approaches (different connection, linkers, oxidation of the PTZ, and addition of methyl groups) have been used to tune the relative energies of the key states and the geometry. Scheme 1 summarizes the synthetic routes used to obtain the various compounds and shows the molecular structures

Mechanochemical bottom-up synthesis of phosphorus-linked, heptazine-based carbon nitrides using sodium phosphide

• Blaine G. Fiss,
• Georgia Douglas,
• Michael Ferguson,
• Jorge Becerra,
• Jesus Valdez,
• Trong-On Do,
• Tomislav Friščić and
• Audrey Moores

Beilstein J. Org. Chem. 2022, 18, 1203–1209, doi:10.3762/bjoc.18.125

• constitutes the building block of g-CN, as opposed to in a linking position. Computational studies by Hartley and Martsinovich have investigated the influence of various linkers, including phosphorus atoms, on both the structure and optical behavior of heptazine-based graphitic carbon nitrides [3]. Yet

• , examples of carbon nitride materials linked together via phosphorus atoms are limited, likely due to challenges in controlling the insertion of phosphorus atoms as linkers under high energy conditions. Mechanochemistry [9][10][11][12] has proven to be effective for the synthesis of a variety of polymers

• establish phosphorus atoms are linkers between heptazine units, X-ray photoelectron spectroscopy (XPS) was used to probe the surface. In g-h-PCN, XPS scans focused on carbon 1s showed three major peaks at 284.7, 286.4, and 288.6 eV, corresponding to C=N, C–OH and C=O signals, respectively (Figure 2a), as

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• highly depends on the molecular design and structures, including linkers, donor and acceptor units, which requires complex and time-consuming molecular synthesis and optimization [21][22][23]. In contrast, the introduction of specific Lewis acid–base pairs in existing molecules can be utilized to achieve

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• advantages of utilizing self-assembly to construct discrete nanocages with predetermined geometry and function is the use of a one-pot reaction employing complementary organic linkers with inorganic metal ions. Although the one-pot synthesis of homoleptic metallacages has been thoroughly investigated over

BINOL as a chiral element in mechanically interlocked molecules

• Matthias Krajnc and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2022, 18, 508–523, doi:10.3762/bjoc.18.53

• -alkylene-linkers, the diastereoselectivity decreases with increasing linker length (79/33/12% de for C3/C6/C12-linkers, respectively). This is in line with an expected localization of the macrocycle around the ester functionality due to weak [C–H···O] interactions from the COOCH2 group to the macrocycle

• ) and in the substitution pattern of the macrocycle (R = H or iPr in the 3,5-positions of the phenylene linkers, for 56 or 57; see Figure 14). These heterobifunctional chiral catalysts were studied for the asymmetric Michael addition of malonic acid diethyl ester (59) to cinnamaldehydes 58. While the

Stepwise PEG synthesis featuring deprotection and coupling in one pot

• Logan Mikesell,
• Dhananjani N. A. M. Eriyagama,
• Yipeng Yin,
• Bao-Yuan Lu and
• Shiyue Fang

Beilstein J. Org. Chem. 2021, 17, 2976–2982, doi:10.3762/bjoc.17.207

• obtained. However, for many other applications, which include as linkers in organic synthesis and bioconjugation [8], as ingredients in nanomedicines to stabilize nanoparticles and to assist nanoparticle cell entry [9][10][11], and as PEGylation agents to stabilize drugs based on biologic molecules such as

• protecting groups would be preferred. Such routes can double the length of the PEG in three easy steps and the PEG product is asymmetric. It is noted that the use of base-labile protecting groups or linkers in organic synthesis involving carrying out reactions under less basic reactions and removing the

• protecting group or cleaving the linker under more basic conditions is not common. In contrast, the use of acid-labile protecting groups or linkers involving carrying out reactions under less acidic conditions and removing the protecting group or cleaving the linker under more acidic conditions is more

Total synthesis of the O-antigen repeating unit of Providencia stuartii O49 serotype through linear and one-pot assemblies

• Tanmoy Halder and
• Somnath Yadav

Beilstein J. Org. Chem. 2021, 17, 2915–2921, doi:10.3762/bjoc.17.199

• for further conjugation to other moieties towards the synthesis of vaccine conjugates by removal of the anomeric PMP group. This has been previously demonstrated by removal of the anomeric PMP group, conversion to a glycosidic donor, and further conjugation to either linkers or amino acids by several

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications

• Nikita Brodyagin,
• Martins Katkevics,
• Venubabu Kotikam,
• Christopher A. Ryan and
• Eriks Rozners

Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116

Recent advances in the application of isoindigo derivatives in materials chemistry

• Andrei V. Bogdanov and
• Vladimir F. Mironov

Beilstein J. Org. Chem. 2021, 17, 1533–1564, doi:10.3762/bjoc.17.111

• , and polymeric isoindigos as agents for photoacoustic and photothermal cancer therapy. Processing conditions and additive influence on OSC performance based on monoisoindigos 9a–c. Structures of linkers in bisisoindigos 14 and 15 and the performance of OSCs based on these. Photovoltaic properties of

Double-headed nucleosides: Synthesis and applications

• Vineet Verma,
• Jyotirmoy Maity,
• Vipin K. Maikhuri,
• Ritika Sharma,
• Himal K. Ganguly and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98

Synthesis and physicochemical evaluation of fluorinated lipopeptide precursors of ligands for microbubble targeting

• Masayori Hagimori,
• Estefanía E. Mendoza-Ortega and
• Marie Pierre Krafft

Beilstein J. Org. Chem. 2021, 17, 511–518, doi:10.3762/bjoc.17.45

• serine–glycine (SG)n segments rather than classical poly(oxyethylene) linkers between the lipid polar head and a targeting ligand were proposed for the liposome-mediated, selective delivery of anticancer drugs. Here, we report the synthesis of perfluoroalkylated lipopeptides (F-lipopeptides) bearing two

Supramolecular polymers with reversed viscosity/temperature profile for application in motor oils

• Jan-Erik Ostwaldt,
• Christoph Hirschhäuser,
• Stefan K. Maier,
• Carsten Schmuck and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2021, 17, 105–114, doi:10.3762/bjoc.17.11

• transformation at elevated temperatures, leading to the desired viscosity effect. The direct comparison of the linkers in A and B strongly suggests that the Thorpe–Ingold effect induced by the gem-dimethyl unit is crucial for the supramolecular polymerization, thus indicating that indeed a ring–chain

Changed reactivity of secondary hydroxy groups in C8-modified adenosine – lessons learned from silylation

• Jennifer Frommer and
• Sabine Müller

Beilstein J. Org. Chem. 2020, 16, 2854–2861, doi:10.3762/bjoc.16.234

• synthesized a number of pyrimidine and purine derivatives carrying amino linkers of different length and flexibility [13][20]. Linker-modified uridine derivatives, upon conversion into phosphoramidite building blocks, were incorporated in RNA and used for a systematic study of distance determination of

Water-soluble host–guest complexes between fullerenes and a sugar-functionalized tribenzotriquinacene assembling to microspheres

• Si-Yuan Liu,
• Xin-Rui Wang,
• Man-Ping Li,
• Wen-Rong Xu and
• Dietmar Kuck

Beilstein J. Org. Chem. 2020, 16, 2551–2561, doi:10.3762/bjoc.16.207

• ]. The acetyl protons of the protected glucose residues appear as eight distinct resonances. The 13C NMR spectrum shows a similar splitting. The triazole carbons resonate at δ = 123.71 and δ = 123.69 ppm and at δ = 143.88 and δ = 143.79 ppm, indicating two sets of magnetically nonequivalent linkers. This

NMR Spectroscopy of supramolecular chemistry on protein surfaces

• Peter Bayer,
• Anja Matena and
• Christine Beuck

Beilstein J. Org. Chem. 2020, 16, 2505–2522, doi:10.3762/bjoc.16.203

• combination of two or more GCP moieties with variable linkers enables the construction of multivalent ligands geared towards a specific spot on protein surface, which by design can lead to either stabilization [42][43][44][45] or inhibition [46] of a given protein–protein interaction. The inhibition of the

Tools for generating and analyzing glycan microarray data

• Akul Y. Mehta,
• Jamie Heimburg-Molinaro and
• Richard D. Cummings

Beilstein J. Org. Chem. 2020, 16, 2260–2271, doi:10.3762/bjoc.16.187

• specialized surface types (e.g., nitrocellulose PATH® slides) which have lower background signals at this wavelength. A decision chart is provided in Figure 2 which can help to decide which surface would be best for a variety of situations. A more detailed discussion of recent glycan linkers and surfaces was

• approach. It is also possible that the results from automated software could be confounding rather than illuminating, if parameters of the experiment or even array fabrication (such as surface chemistry, etc.) are changed. In fact, the various chemical linkers through which glycans are attached to the

Clickable azide-functionalized bromoarylaldehydes – synthesis and photophysical characterization

• Dominik Göbel,
• Marius Friedrich,
• Enno Lork and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2020, 16, 1683–1692, doi:10.3762/bjoc.16.139

• alkynes, exhibiting different degrees of steric demand, was performed in high efficiency. Finally, we investigated the photophysical properties of the azide-functionalized arenes and their covalently linked triazole derivatives to gain deeper insight towards the effect of these covalent linkers on the

Pauson–Khand reaction of fluorinated compounds

• Jorge Escorihuela,
• Daniel M. Sedgwick,
• Alberto Llobat,
• Mercedes Medio-Simón,
• Pablo Barrio and
• Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

• compounds in the PK reaction started with fluorinated enynes derived from malonates and those containing heteroatoms as linkers. The synthesis of the starting enynes 37 was accomplished following various approaches (Scheme 19). The first of these (via a) was based on a report by Hammond and co-workers, in

• ). Alkyl-substituted derivatives proved to be similarly successful substrates; however, the TMS-substituted derivative was obtained in a significantly lower yield. In terms of linkers, heteroatoms were well-tolerated, although the use of malononitrile resulted exclusively in the elimination product despite

• testing a variety of reaction conditions. More complex biorelevant examples such as isatin derivatives were also suitable substrates, affording the corresponding spirocyclic derivatives, albeit in low yields (Scheme 21) [59]. Unfortunately, thioether and sulfone-based linkers were unsuitable in this

A smart deoxyribozyme-based fluorescent sensor for in vitro detection of androgen receptor mRNA

• Ekaterina A. Bryushkova,
• Erik R. Gandalipov and
• Julia V. Nuzhina

Beilstein J. Org. Chem. 2020, 16, 1135–1141, doi:10.3762/bjoc.16.100

• strand), that combined the components into a single structure. The T1–T4 strands were connected with the platform by polythymidine or hexaethylene glycol linkers, which provided flexibility of SDFS. All nucleotide sequences are presented in Table S2 of Supporting Information File 1. A calculation of the

• target 60-AR_RNA, and connected with T2 and T3 strands through polythymidine linkers (Figure 1A). The MGA strands can hybridize with each other and attach a molecule of malachite green dye (Figure 1C and D) only in the presence of target mRNA. It provided the high specificity of SDFS. After being

• biological material. SDFS main components and its work model. A) Schematic representation of the SDFS structure. Dotted lines indicate hexaethylene glycol linkers in T1 and T4, and polythymidines linker in T2 and T3; Dz1 and Dz2 – deoxyribozyme sequences. B) The detailed structure of the Dz catalytic core

Towards triptycene functionalization and triptycene-linked porphyrin arrays

• Gemma M. Locke,
• Keith J. Flanagan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2020, 16, 763–777, doi:10.3762/bjoc.16.70

• porphyrin units have been connected in a number of different ways; from phenylene, ethynyl, ethenyl or alkane linkers [5][6][7][8], to meso–β- [9] or β–β-linkages [10] or alternatively by connecting two or more meso–meso-linked porphyrin units via oxidative fusing reactions [11][12][13][14][15]. However

• linked which, theoretically, can cause a significant energy/charge sink. Moreover, the use of π-conjugated linkers in porphyrin arrays results in significantly altered UV–vis spectra, indicating very strong electronic coupling that causes the loss of individual unit characteristics through delocalization

• directly to the periphery of triptycene or via various linkers; arrays with six chromophores 3 have thus far eluded us [26][27]. While much work has been done on the functionalization of the aromatic rings of triptycene as in 2 or 3 [24][25][26][27][28][29][30], the attachment of chromophores at the

Fluorinated maleimide-substituted porphyrins and chlorins: synthesis and characterization

• Valentina A. Ol’shevskaya,
• Elena G. Kononova and
• Andrei V. Zaitsev

Beilstein J. Org. Chem. 2019, 15, 2704–2709, doi:10.3762/bjoc.15.263

• heterocycles have also been used as linkers and for labeling biomolecules in chemical biology [43]. Moreover, this synthetic approach provides high yields, selectivity, mild reaction conditions and simple purification methods. It was demonstrated that the CuAAC reaction of porphyrins 3a and 3b with N

Effect of ring size on photoisomerization properties of stiff stilbene macrocycles

• Sandra Olsson,
• Óscar Benito Pérez,
• Magnus Blom and
• Adolf Gogoll

Beilstein J. Org. Chem. 2019, 15, 2408–2418, doi:10.3762/bjoc.15.233

• diethers into noncyclic diethers (Supporting Information File 1) and the results are visualized in Figure 4. For (E)-1a–d the ring strain decreases with increased linker length. For the less strained (Z)-1a–d the ring strain increases slightly with increased linker length and for the longer linkers (1c,d

Complexation of chiral amines by resorcin[4]arene sulfonic acids in polar media – circular dichroism and diffusion studies of chirality transfer and solvent dependence

• Bartosz Setner and
• Agnieszka Szumna

Beilstein J. Org. Chem. 2019, 15, 1913–1924, doi:10.3762/bjoc.15.187

• capable of forming electrostatic interactions. However, in CSAs polar groups are positioned directly on a macrocyclic scaffold, while for RSAs at conformationally labile methylene linkers. Therefore, we think that RSAs are more adaptable than CSAs and are able to enclose guest molecules more tightly (by