1931-44-8Relevant articles and documents
Chemistry of Heterocyclic Compounds. 61. Synthesis and Conformational Studies of Macrocycles Possessing 1,8- or 1,5-Naphthyridino Subunits Connected by Carbon-Oxygen Bridges
Newkome, George R.,Garbis, Sam J.,Majestic, Veronica K.,Fronczek, Frank R.,Chiari, Giacomo
, p. 833 - 839 (1981)
Polyethereal macrocycles were prepared from both 2,6-dichloro-1,5-naphthyridine (2) and 2,7-dichloro-1,8-naphthyridine (6).The "cross-the-face" structures of 1:1 macrocycles 7, derived from 2, were confirmed by NMR.The 2,7-(1,8-naphthyridino) macrocyclic structures 9 and 10 were also supported by NMR data which were indicative of diminished N-electron density, when compared to the parent 1,8-naphthyridine.Template reactions did not appreciably enhance product yields.The X-ray crystal structure of 1:1 macrocycle 9b was conducted and showed that the imidate moieties possess a nearly 0 deg dihedral angle and that the naphthyridine subunit exhibits marginal deviation from planarity.
Dynamic Cross-Linking of Polyethylene via Sextuple Hydrogen Bonding Array
Tellers, Jonathan,Canossa, Stefano,Pinalli, Roberta,Soliman, Maria,Vachon, Jér?me,Dalcanale, Enrico
, p. 7680 - 7691 (2018)
Multiple hydrogen bonding motifs are promising tools for polymer functionalization to obtain adaptable networks combining advantages of permanently cross-linked systems with processability of thermoplastics. Here we describe the use of a new multiple hydrogen bonding motif to impart increased tensile strength, stiffness, barrier properties, and a plateau modulus after melting to functional polyolefins, while retaining adaptability of the polymer network. The cross-linked nature of these polymers was elucidated by thermal and mechanical analysis, revealing a raised glass transition and rheology similar to permanently cross-linked polymer matrices. The apolar polymer matrix was found to stabilize the new hydrogen bonding motif at elevated temperatures. The resulting polymer showed thermal resistance superior to ureidopyrimidone (UPy) motif functionalized materials, the most commonly employed synthetic multiple hydrogen bonding motif to date.
Hydrogen-bond-driven dimers of naphthyridine derivatives for selective identification of DNA G-quadruplexes
Gao, Lianxun,Hao, Xueyu,Jin, Rizhe,Kang, Chuanqing,Li, Chunjie,Ma, Xiaoye,Wang, Liangpeng,Wang, Yu
supporting information, p. 4768 - 4774 (2021/06/11)
G-quadruplex (GQ) ligands as potential anti-cancer drugs have received extensive attention. Large aromatic systems are usually considered in the design of the ligands to improve the binding with GQs, which are typically constructed by the combination of small modules with covalent bonds. In this study, we presented a non-covalent bond approach to construct GQ ligands with an extended planar structure. The ligands were stable dimers assembled through quadruplex intermolecular hydrogen bonds between two molecules of naphthyridine derivatives. Spectroscopic analyses showed that dimeric ligands could stabilize GQs with an increase of the melting temperature up to 12 °C and induced conformational conversion of hybrid GQs. Confocal fluorescence microscopy confirmed the enrichment of naphthyridine ligands in the nucleus. The ligands showed moderate cytotoxicity against HeLa cells with an IC50 value of 7.5 μg mL-1 and effectively induced growth inhibition and apoptosis in HeLa cells. These results confirmed the feasibility of the quick building of GQ ligands through intermolecular interactions of simple molecules that are easily obtained during synthesis, which is helpful for GQ ligand design and quick establishment of a ligand library through the self-assembly of easily available molecular components.
Muscle-Mimetic Synergistic Covalent and Supramolecular Polymers: Phototriggered Formation Leads to Mechanical Performance Boost
Zhang, Zhaoming,Cheng, Lin,Zhao, Jun,Zhang, Hao,Zhao, Xinyang,Liu, Yuhang,Bai, Ruixue,Pan, Hui,Yu, Wei,Yan, Xuzhou
supporting information, p. 902 - 911 (2020/12/22)
A thin filament stimulated by Ca2+ to combine with myosin is the structural basis to achieve filament sliding and muscle contraction. Though a large variety of artificial materials has been developed by mimicking muscle, the on-demand combination of the actin filament and myosin has never been precisely reproduced in polymeric systems. Herein, we show that both the combination process and the combined structure of actin filament and myosin have been mimicked to construct synergistic covalent and supramolecular polymers (CSPs). Specifically, photoirradiation as a stimulus induces the independently formed covalent polymers (CPs) and supramolecular polymers (SPs) to interact with each other through activated quadruple H-bonding. The resultant CSPs possess a unique network structure which not only facilitates the synergistic effect of CPs and SPs to afford stiff, strong, yet tough materials but also provides efficient pathways to dissipate energy with the damping capacity of the representative material being higher than 95%. Furthermore, muscle functions, for example, by becoming stiff during contraction and self-growth by training, are imitated well in our system via in situ phototriggered formation of CSP in the solid state. We hope that the fundamental understanding gained from this work will promote the development of synergistic CSP systems with emergent functions and applications by mimicking the principle of muscle movements.
