Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• linked through alkyl ether linkers, creating a crown ether-like core around the periphery of the calix[4]arene macrocycle (Scheme 3) [104]. The conformationally cone-locked receptor 7 showed the binding of monohydrated fluoride within the core. The F− anion was encapsulated within the central cavity

• accordion porphyrins with various linkers [54][125]. Their formation typically relied on a template synthesis approach [126][127]. The first reported accordion porphyrin was synthesised as a binucleated lead(II) complex 13 (Scheme 4) [52]. The reaction of diformyldipyrromethane 12, lead(II) thiocyanate, and

• 1,3-diaminopropane yielded 13 selectively. Later, Bowman-James and co-workers introduced a series of binucleated accordion porphyrins differing in the linkers connecting two parts of the dimeric macrocycle exploiting the barium(II)-templated reactions [53]. The coordination chemistry of accordion

Linker, loading, and reaction scale influence automated glycan assembly

• Marlene C. S. Dal Colle,
• Manuel G. Ricardo,
• Nives Hribernik,
• José Danglad-Flores,
• Peter H. Seeberger and
• Martina Delbianco

Beilstein J. Org. Chem. 2023, 19, 1015–1020, doi:10.3762/bjoc.19.77

• mostly performed on cross-linked polystyrene resins equipped with photocleavable linkers [3], offering orthogonality to all the synthetic steps of the assembly, while selectively releasing the glycan at the end of the synthesis. In recent years, the implementation of new synthetic strategies [4][5][6][7

• scale [19], and linkers [20][21] affect the overall yield of solid phase peptide synthesis (SPPS). In the past decades, several supports and linkers have been developed and commercialized for SPPS, enabling a wide range of applications. Solid supports are available with different linker loadings, with

• productivity of AGA. Results and Discussion We selected three glycan sequences as models to analyze the effect of different parameters on the AGA outcome. Each sequence was prepared on four batches of Merrifield resin functionalized with two photolabile linkers (L1 [22] vs L2 [3]), at two linker loadings (low

Light-responsive rotaxane-based materials: inducing motion in the solid state

• Adrian Saura-Sanmartin

Beilstein J. Org. Chem. 2023, 19, 873–880, doi:10.3762/bjoc.19.64

• struts and the photoresponsive linkers. The use of ditopic interlocked building blocks, such as that employed to form mainly a cyclic hetero[4]pseudorotaxane from a self-complementary [2]rotaxane [73], is also envisioned as a strategy that will be employed in the future to dynamically change the

Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• this [7]helicene family by introducing different linkers such as nitrogen, sulfur, sulfone, ketone, methylene, and derivatives of ketone [44]. Due to the varied nature of the different linkers, the photophysical and semiconductor properties can be effectively tuned. Feng and co-workers reported a

• reported a new family of chiral NGs, which constituted by two orthogonal dibenzo[fg,ij]phenanthro-[9,10,1,2,3-pqrst]pentaphene (DBPP) units covalently connected through tetrafluorophenylene (61) [49] or octafluoro-9,10-anthracenylene (65) [50] linkers. The synthesis started with a double Pd-catalyzed

• nanographenes 96 and 100 using helicene or oxa-helicene as the linkers, respectively [56]. The first π-extension started from the borylated penta-tert-butyl HBC 92. The chemical selective Suzuki−Miyaura cross-coupling reaction between 92 and 93 followed by Scholl oxidation produced compound 94 in an overall 50

Strategies in the synthesis of dibenzo[b,f]heteropines

• David I. H. Maier,
• Barend C. B. Bezuidenhoudt and
• Charlene Marais

Beilstein J. Org. Chem. 2023, 19, 700–718, doi:10.3762/bjoc.19.51

• ) [77][78]. The allyl moiety in 144 allows for facile further functionalization. Amidation of the dihydrodibenzo[b,f]azepine (2a) derivatives with acyl halides 145 allowed for the introduction of variable length amide linkers by Kastrinsky et al. [3] (Scheme 33B). An industrial synthesis of opipramol (5

Synthesis, structure, and properties of switchable cross-conjugated 1,4-diaryl-1,3-butadiynes based on 1,8-bis(dimethylamino)naphthalene

• Semyon V. Tsybulin,
• Ekaterina A. Filatova,
• Alexander F. Pozharskii,
• Valery A. Ozeryanskii and
• Anna V. Gulevskaya

Beilstein J. Org. Chem. 2023, 19, 674–686, doi:10.3762/bjoc.19.49

• , including naphthalene cores, butadiyne and acetylene linkers. The main structural parameters of diynes 5 that characterize the degree of this distortion are presented in Table 2, where ϕ1 is the angle between the planes of the benzene ring and the neighboring naphthalene system, ϕ2 is the angle between the

• characterized by the least distortion of the DMAN fragments in the series (twisting Θ = 9.45 and 12.83°, torsions φA = 20.9° and φB = 8.4°, bond angle deviations in both butadiyne and acetylene linkers do not exceed 6°). In the crystal packing of 5d (see Supporting Information File 1, Figures S64 and S65), the

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

• Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

• -triazole-ruthenium(II) conjugates 112a,b and 116a,b in 18–20% yield. Their photophysical and electrochemical studies revealed that the orbital energies depend on the ligands/linker, connecting pattern of linkers, and the presence of Zn metal ions in the porphyrin core. Ligand exchange studies also

• 126, it was used to form water-soluble porphyrin nanospheres by self-inclusion complex formation in water. Tritriazole-bridged porphyrin system This section contains the synthesis of porphyrin conjugates having three 1,2,3-triazole groups as linkers. In 2012, Beletskaya and co-workers [55] described

• % yield using Cu(MeCN)4PF6 and triethylamine in anhydrous DMF. This ‘capped’ porphyrin was designed so that the rigid triazole linkers prevent the capping group from collapsing onto the porphyrin. Gilday et al. [60] also synthesized porphyrin 142 and studied its anion-binding properties and found that it

A study of the DIBAL-promoted selective debenzylation of α-cyclodextrin protected with two different benzyl groups

• Naser-Abdul Yousefi,
• Morten L. Zimmermann and
• Mikael Bols

Beilstein J. Org. Chem. 2022, 18, 1553–1559, doi:10.3762/bjoc.18.165

• linkers, lids or catalytic groups can be installed which is no simple task due to the many similar functionalities in 1 [5][6][7]. A very useful way to access the hydroxy groups in a selective manner is the perbenzylation of 1 and the subsequent selective debenzylation of 2 using DIBAL [8][9][10]. This

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