105-09-9Relevant articles and documents
A Modular Synthesis of Multidentate S-, N- and O-Containing Meta- and Paracyclophanes
Rasheed, Omer K.,Bailey, Patrick D.,Lawrence, Amy,Quayle, Peter,Raftery, James
, p. 6988 - 6993 (2015)
The development of a modular approach to macrocycle assembly has enabled the synthesis of a library of pyridine-based macrocycles possessing multiple donor sites where chirality was readily introduced from (R)- or (S)-alanine, a representative amino acid. The facile, regioselective, nucleophilic ring opening of aziridines by dithiols enabled the synthesis of thioether-based linkers which on subsequent alkylation provided access to optically pure macrocycles. A modular approach to macrocyclic assembly has enabled the synthesis of a library of macrocycles possessing multiple donor sites where chirality was readily introduced from (S)-alanine. Key to this approach was the facile, regioselective, nucleophilic ring opening of aziridines by dithiols followed by macrocylisation under conditions of high dilution.
Co-crystal formation between 2-amino-4,6-dimethylpyrimidine and new p-xylylene-bis(thioacetic) acid
Ostasz,Lyszczek,Mazur,Tarasiuk
, p. 10262 - 10272 (2014)
Novel p-xylylene-bis(thioacetic) acid (p-XBTA) and its co-crystals with 2-amino-4,6-dimethylpyrimidine (DMP) have been synthesized and characterized by single-crystal X-ray diffraction, infrared spectroscopy and thermal analysis methods (TG/DSC). Depending on the crystallization conditions, three different multicomponent crystal forms have been isolated with various chemical compositions and stoichiometries of the co-formers. The ATR-FTIR spectra of the co-crystals display the stretching vibration bands for the co-formers with associated shifts confirming the formation of new phases. DSC and TG were used to reveal the relative stabilities of new solids compared to those of the co-formers.
Stereoretentive Ring-Opening Metathesis Polymerization to Access All- cis Poly(p-phenylenevinylene)s with Living Characteristics
Hsu, Ting-Wei,Kim, Cheoljae,Michaudel, Quentin
, p. 11983 - 11987 (2020)
Poly(p-phenylenevinylene)s (PPVs), a staple of the conductive polymer family, consist of alternating alkene and phenyl groups in conjugation. The physical properties of this organic material are intimately linked to the cis/trans configuration of the alkene groups. While many synthetic methods afford PPVs with all-trans stereochemistry, very few deliver the all-cis congeners. We report herein a synthesis of all-cis PPVs with living characteristics via stereoretentive ring-opening metathesis polymerization (ROMP). Exquisite catalyst control allows for the preparation of homopolymers or diblock copolymers with perfect stereoselectivity, narrow dispersities, and predictable average molar masses. All-cis PPVs can then serve as light-responsive polymers through clean photoisomerization of the stilbenoid units.
Synthesis of planar chiral N-heterocyclic-substituted pyridinophanes
Kramer, Joshua J. P.,Nieger, Martin,Braese, Stefan
, p. 541 - 549 (2013)
Four new planar chiral N-heterocyclic-substituted [2](1,4)benzene[2](2,5) pyridinophanes have been synthesized. With the attached pyrazole, triazole, tetrazole, and pyrimidine moieties, different N,N-chelating ligands that vary in the number of enclosed nitrogen atoms, ring size, and electronic properties were added to a mostly neglected class of pyridinophanes. Additionally, the known synthesis of the pyridinophane scaffold was simplified considerably. With the acetyl, amino, and amido pyridinophane, various useful intermediates for new pyridinophane ligands were synthesized, which would allow for further investigations of this ligand system. New planar chiral bis(heterocyclic) N-donors based on the rarely investigated class of [2](1,4)-benzene[2](2,5) pyridinophanes were synthesized. The synthesis of the pyridinophane scaffold was simplified, and a pyrazole, triazole, tetrazole, and pyrimidine heterocycle were successfully attached to the planar chiral backbone. Copyright
Synthesis and photophysics of new pyridyl end-capped 3D-dithia[3.3]paracyclophane-based Janus tectons: Surface-confined self-assembly of their model pedestal on HOPG
Attias, A.-J.,Auffray, M.,Charra, F.,Kreher, D.,Mathevet, F.,Sosa Vargas, L.
, p. 7665 - 7674 (2020)
Surface-confined supramolecular self-assembly is currently a promising strategy to create well-organised 2D-networks on conducting surfaces. However, using such substrates tends to quench any electronic properties of the adsorbed molecules. In this context, new pyridyl end-capped 3D-dithia[3.3]paracyclophane-based molecules were designed, along with their model compound (pedestal), with the objective of self-assembling these tectons on any substrate. The synthesis of these new molecules was not straightforward and is consequently described in detail. Once the materials were successfully isolated, their optoelectronic properties were investigated to study potential non-covalent interactions: through pH-dependent absorption and emission measurements, and infra-red spectrometry. We evidenced that both ionic bonding and coordination bonding are compatible with the molecules design. Finally, preliminary scanning tunneling microscopy (STM) studies were performed to study the supramolecular self-assembly properties of the model lower-deck (pedestal) on highly oriented pyrolytic graphite (HOPG): we observed a quasi-square lattice of self-assembled 2D-networks that appear to form independently of the underlying HOPG lattice.
Alkyl substituted [2.2]paracyclophane-1,9-dienes
Lidster, Benjamin J.,Kumar, Dharam R.,Spring, Andrew M.,Yu, Chin-Yang,Helliwell, Madeleine,Raftery, James,Turner, Michael L.
, p. 6079 - 6087 (2016)
[2.2]Paracyclophane-1,9-dienes substituted with n-octyl chains have been synthesised from the corresponding dithia[3.3]paracyclophanes using a benzyne induced Stevens rearrangement. The use of 2-(trimethylsilyl)phenyl trifluoromethanesulfonate and tetra-n-butylammonium fluoride as the in situ benzyne source gave significantly improved yields over traditional sources of benzyne and enabled the preparation of n-octyl substituted [2.2]paracyclophane-1,9-dienes on a multi-gram scale.
Water-soluble trithiolato-bridged dinuclear ruthenium(II) and osmium(II) arene complexes with bisphosphonate functionalized ligands as anticancer organometallics
Harringer, Sophia,Hejl, Michaela,Jakupec, Michael A.,Kandioller, Wolfgang,Keppler, Bernhard K.,Riedl, Christoph A.,Rosner, Alexander,Salomon, Philipp
, (2021/10/04)
Trithiolato-bridged dinuclear ruthenium(II) complexes [Ru2(p-cym)2(SR)3]Cl (p-cym = p-cymene, R = benzyl derivatives) are regarded as the most cytotoxically potent metal(II) arene antineoplastics, but are oftentimes limited by their poor solubility in aqueous media. Thus, we designed bisphosphonate-functionalized ligands for use in a modular two-step complexation process to synthesize six trithiolato-bridged dinuclear ruthenium(II) and osmium(II) arene complexes bearing one to three bisphosphonate-benzylmercaptane derived ligands. In addition to improved aqueous solubility the high affinity of bisphosphonates towards apatite structures found in bone and bone metastases may grant selective targeting properties to functionalized organometallics. The complex stabilities and hydroxyapatite binding behavior were determined by UV/Vis spectroscopy. The bisphosphonate functionalization decreases antiproliferative activity in vitro, which was correlated to lower cellular accumulation, due to the different lipophilic profiles of the drug candidates.
Enhancing Insulated Conjugated Polymer Fluorescence Quenching by Incorporating Dithia[3.3]paracyclophanes
Lillis, Ryan,Thomas, Maximillian R.,Mohanan, Manikandan,Gavvalapalli, Nagarjuna
, p. 3112 - 3119 (2021/05/05)
Insulated π-conjugated polymers exhibit enhanced chemical stability, photostability, fluorescence quantum yield, electroluminescence, solubility, and intrachain charge transport. However, insulated polymer fluorescence quenching by acceptor molecules is significantly hampered as the π-face is insulated. Photoinduced charge transfer is one of the key steps in amplified fluorescence quenching sensors and organic solar cells for charge generation. Inspired by the myelin sheath gaps in nerve cell axons, herein, we synthesized a series of insulated random copolymers of adamantanocyclophane with an increasing percentage of dithia[3.3]paracyclophane (PCP) from 5 to 30% to enhance the insulated polymer fluorescence quenching with acceptor molecules. As the percentage of the dithia[3.3]paracyclophane monomer increases, the copolymers showed an increase in absorption in the red region of the spectrum and also the copolymers' photoluminescence quantum yield reduced. The Stern-Volmer quenching constant of the 30% copolymer is ca. 4.5 times higher than that of the adamantanocyclophane homopolymer. A comparison with the control polymers indicated that the through-space-coupled interactions in PCP could be a plausible reason for the enhanced fluorescence quenching in copolymers in addition to the reduced steric hindrance by PCP. The developed copolymers combine the advantages of polymer insulation without significantly sacrificing the photoinduced charge transfer, which will help further their applicability as amplified fluorescence quenching sensors and in organic solar cells.
A dual wavelength polymerization and bioconjugation strategy for high throughput synthesis of multivalent ligands
Li, Zihao,Kosuri, Shashank,Foster, Henry,Cohen, Jarrod,Jumeaux, Coline,Stevens, Molly M.,Chapman, Robert,Gormley, Adam J.
supporting information, p. 19823 - 19830 (2019/12/25)
Structure–function relationships for multivalent polymer scaffolds are highly complex due to the wide diversity of architectures offered by such macromolecules. Evaluation of this landscape has traditionally been accomplished case-by-case due to the experimental difficulty associated with making these complex conjugates. Here, we introduce a simple dual-wavelength, two-step polymerize and click approach for making combinatorial conjugate libraries. It proceeds by incorporation of a polymerization friendly cyclopropenone-masked dibenzocyclooctyne into the side chain of linear polymers or the α-chain end of star polymers. Polymerizations are performed under visible light using an oxygen tolerant porphyrin-catalyzed photoinduced electron/energy transfer-reversible addition–fragmentation chain-transfer (PET-RAFT) process, after which the deprotection and click reaction is triggered by UV light. Using this approach, we are able to precisely control the valency and position of ligands on a polymer scaffold in a manner conducive to high throughput synthesis.
Mild and efficient methods for the conversion of benzylic bromides to benzylic thiols
Han, Chien-Chung,Balakumar
, p. 8255 - 8258 (2007/10/03)
Very mild and efficient methods are established for the conversion of the benzylic bromides at room temperature to their corresponding benzylic thiols with high yields (94-99%) in 1 h under N2.
