783334-78-1Relevant articles and documents
Discotic liquid crystals of transition metal complexes 58: Novel phthalocyanine-based mesogenic monomers and polymers exhibiting spontaneous homeotropic alignment and helical tetragonal columnar structure
Suzuki-Ichihara, Ayumi,Sugibayashi-Kajita, Makiko,Ariyoshi, Masahiro,Yasutake, Mikio,Ohta, Kazuchika
, p. 800 - 817 (2021/05/27)
Two synthetizations of a novel series of phthalocyanine-based discotic liquid crystals substituted by a polymerizable group, acryloyl group or a norbornene group: 2-(12-acryloyloxydodecyloxy)-3-methoxy-9,10,16,17,23,24-hexakis (3,4-dialkoxyphenoxy)phthalocyaninato copper(II) [abbreviated as (n,12)PcCu(OCH3)(Acryloyl) (7: e (n = 10), f (n = 12), g (n = 14))] and 2-(12-norborn-2-ene carbonyloxydodecyloxy)-3-methoxy-9,10,16,17,23,24-hexakis(3,4-dialkoxyphenoxy)-phthalocyaninato copper(II): [abbreviated as (n, 12)PcCu(OCH3)(Norb) (9e, f, g)]. Their liquid crystalline properties and homeotropic alignment were investigated using a polarizing microscope, a differential scanning calorimetry (DSC), and a temperature-variable X-ray diffractometer. As a result, each of the derivatives gave a Coltet mesophase in the higher temperature region, displaying perfect homeotropic alignment between the two glass plates. In order to obtain the thin film while keeping their homeotropic alignment at room temperature, attempts to polymerize the monomers, 7 and 9, in the Coltet phase showed homeotropic alignment. The polymerization of the acryloyl-substituted monomers (7) was not successful in any of the methods, whereas the polymerization of norbornene-substituted monomers (9) was quite successful by ring-opening metathesis polymerization with a Grubbs catalyst to obtain the novel polymers, poly-(n, 12)PcCu(OCH3)(Norb) (10e, f, g). Each of the polymers (10) were found to show a perfect homeotropic alignment from room temperature to ca. 200°C of the decomposition temperature. Moreover, it was also revealed from temperature-variable small-angle X-ray diffraction studies that each of the polymers 10 showed a helical Coltet (helical tetragonal columnar) structure. The helical Coltet phase structure may be able for use in organic electroluminescent devices and solar cells in the future.
Recyclable iron(ii) caffeine-derived ionic salt catalyst in the Diels-Alder reaction of cyclopentadiene and α,β-unsaturated: N -acyl-oxazolidinones in dimethyl carbonate
Meng, Di,Li, Dazhi,Ollevier, Thierry
, p. 21956 - 21963 (2019/07/30)
Iron(ii) triflate was used in combination with caffeine-derived salts as recyclable catalysts for the Diels-Alder reaction run in dimethyl carbonate (DMC) as a green solvent. The catalyst was prepared as an ionic salt from a xanthinium salt and Fe(OTf)2. Various substrates including α,β-unsaturated carbonyl and N-acyloxazolidinone derivatives were reacted with cyclopentadiene using this recyclable catalyst. The use of a low catalyst loading (1 mol%) afforded high yields (up to 99%) of the corresponding cycloadducts. The recycling and the efficiency of the catalyst were demonstrated for several runs.
Synthesis of Bicyclic Isocyanates and Bioisosteric 1,3-Disubstituted Ureas as Soluble Epoxide Hydrolase Inhibitors
Burmistrov,D’yachenko,Rasskazova,Butov
, p. 1166 - 1176 (2019/10/19)
(1S)-1-Isocyanato-4,7,7-trimethyl-2-oxabicyclo[2.2.1]heptan-3-one and 2-isocyanatobicyclo[2.2.1]-hept-5-ene were prepared by the Curtius rearragement reaction from the corresponding carboxylic acids. The synthesized isocyanates were used to synthesize, in high yields of 74–93%, bioisosteric 1,3-disubstituted ureas as potential human soluble epoxide hydrolase inhibitors.
Ion Conducting ROMP Monomers Based on (Oxa)norbornenes with Pendant Imidazolium Salts Connected via Oligo(oxyethylene) Units and with Oligo(ethyleneoxy) Terminal Moieties
Price, Terry L.,Choi, U Hyeok,Schoonover, Daniel V.,Arunachalam, Murugan,Xie, Renxuan,Lyle, Steven,Colby, Ralph H.,Gibson, Harry W.
, p. 1371 - 1388 (2019/02/19)
A matrix of 22 two-armed norbornene-based imidazolium TFSI monomers (8) was synthesized to determine the optimal structure in terms of single ion conductivity. For the chain tethering the imidazolium ring to the norbornene ring three or four oxyethylene units are optimal. A terminal group of two ethyleneoxy units was optimal. NMR studies indicated that both the tether oxyethylene units and the terminal ethyleneoxy units interact with the imidazolium cation via hydrogen bonding. 8r (X = 4, Y = 2) exhibited a conductivity of 9.57 × 10-5 S/cm at 25 °C and a Tg of -46 °C. Low Tg values do not correlate with higher conductivity as a result of the H-bonding interactions. Stability toward autopolymerization and reasonable conductivities provide an acceptable platform for ion conducting ROMP polymers. Four one-armed norbornene-based imidazolium TFSI monomers (15) were prepared with tetra(ethyleneoxy) linkers/spacers and variable terminal groups. All of these exhibited low Tgs (10-4 S/cm, the highest being 4.39 × 10-4 S/cm for 15c (Tg = -69 °C), the analogue of 8r, providing hope for outstanding polymers. Three oxanorbornene-based two-armed imidazolium TFSI monomers (18) were prepared with varied linkers and terminal groups. 18b possesses a room temperature conductivity of 1.2 × 10-4 S/cm, again augering well for polymers derived therefrom by ROMP.
Natural Triterpenoid- and Oligo(Ethylene Glycol)-Pendant-Containing Block and Random Copolymers: Aggregation and pH-Controlled Release
Li, Ying,Gao, Yuxia,Wang, Bo,Hao, Jie,Hu, Jun,Ju, Yong
supporting information, p. 2723 - 2729 (2018/09/06)
In this research, a series of random and block amphiphilic copolymers of norbornene derivatives containing biocompatible natural triterpenoid and oligo(ethylene glycol) pendants were synthesized by ring-opening metathesis polymerization. These copolymers were heat and pH responsive, and could self-assemble into core–shell spherical micelles in aqueous solution. Their hydrodynamic diameters corresponded to pH values and monomer sequences. By evaluating the loading and release capacity of hydrophobic molecules, it was found that 1) the higher the content of the hydrophobic triterpenoid, the higher the loading capacity; 2) the release speed could be trigged by the pH because of the deprotonation of the carboxyl groups on the triterpenoid. Additionally, the copolymers exhibited low cytotoxicity toward L929 cells, which makes them potential nanocarrier candidates for controlled drug delivery.
Visible Light-Mediated Decarboxylative Alkylation of Pharmaceutically Relevant Heterocycles
Sun, Alexandra C.,McClain, Edward J.,Beatty, Joel W.,Stephenson, Corey R. J.
supporting information, p. 3487 - 3490 (2018/06/26)
A net redox-neutral method for the decarboxylative alkylation of heteroarenes using photoredox catalysis is reported. Additionally, this method features the use of simple, commercially available carboxylic acid derivatives as alkylating agents, enabling the facile alkylation of a variety of biologically relevant heterocyclic scaffolds under mild conditions.
Dye functionalized-ROMP based terpolymers for the use as a light up-converting material: Via triplet-triplet annihilation
Hollauf,Zach,Borisov,Müller,Beichel,Tscherner,K?stler,Hartmann,Knall,Trimmel
, p. 7535 - 7545 (2017/08/16)
In this paper we introduce and compare different terpolymers comprising covalently attached sensitizer and emitter chromophores for the use as a light up-converting material via triplet-triplet annihilation (TTA). Using the advantages of ring opening metathesis polymerisation it was possible to prepare five different polymer architectures in order to investigate the influence of polymer architecture and chromophore arrangement on the photon up-conversion behaviour. First, two new monomers containing the chromophores have been synthesized and characterized in regard to their photophysical characteristics suitable for triplet-triplet annihilation dye pair. For this purpose, a derivative of Pt(ii) meso-tetraphenyltetra(tert-butyl)benzoporphyrin as sensitizer and a perylenediester as emitter were attached to norbornene moieties via ester linkages. Polymerisations of these monomeric chromophores were performed in combination with dimethyl 5-norbornene-2,3-dicarboxylate as matrix monomer. Depending on the location of the dye molecules on the polymer chain, large differences in the TTA efficiency were observed. The best quantum yields have been achieved with a completely statistically distributed terpolymer showing an up-conversion quantum yield of up to 3% in solution.
Visible-Light-Mediated Synthesis of Amidyl Radicals: Transition-Metal-Free Hydroamination and N-Arylation Reactions
Davies, Jacob,Svejstrup, Thomas D.,Fernandez Reina, Daniel,Sheikh, Nadeem S.,Leonori, Daniele
supporting information, p. 8092 - 8095 (2016/07/16)
The development of photoredox reactions of aryloxy-amides for the generation of amidyl radicals and their use in hydroamination-cyclization and N-arylation reactions is reported. Owing to the ease of single-electron-transfer reduction of the aryloxy-amides, the organic dye eosin Y was used as the photoredox catalyst, which results in fully transition-metal-free processes. These transformations exhibit a broad scope, are tolerant to several important functionalities, and have been used in the late-stage modification of complex and high-value N-containing molecules.
Palladium-catalyzed double activation and arylation of 2° and 3° C(sp3)-H bonds of the norbornane system: Formation of a C-C bond at the bridgehead carbon and bridgehead quaternary stereocenter
Parella, Ramarao,Babu, Srinivasarao Arulananda
supporting information, p. 1395 - 1402 (2014/06/23)
Pd-catalyzed activation and direct arylation of both 2° and the bridgehead 3° (sp3) C-H bonds and an unprecedented C-C bond formation at the bridgehead carbon of the norbornane system are reported. The assembly of bridgehead-substituted norbornane frameworks having contiguous stereocenters was accomplished. X-ray crystal structure analysis of representative molecules unambiguously established the stereochemistry.
Biorenewable ROMP-based thermosetting copolymers from functionalized castor oil derivative with various cross-linking agents
Ding, Rui,Xia, Ying,Mauldin, Timothy C.,Kessler, Michael R.
, p. 5718 - 5726 (2014/12/11)
A new norbornenyl-functionalized castor oil alcohol (NCA) was synthesized and ring-opening metathesis copolymerized separately with two norbornene-based cross-linking agents: dicyclopentadiene (DCPD) and a bifunctional norbornene crosslinker (CL). Isothermal differential scanning calorimetry (DSC) was used to examine the cure behavior of NCA/DCPD and NCA/CL resins, through which a reasonable cure schedule was determined. The glass transition temperature (Tg) and storage modulus (E′), characterized by dynamic mechanical analysis (DMA), increased significantly in both copolymer systems with the addition of cross-linking agents. Cross-link density of the two systems was evaluated using a modified empirical equation from the kinetic theory of rubber elasticity. Differences in tensile stress-strain behavior and thermal stability between polymerized NCA/DCPD and NCA/CL were correlated to the structural rigidity and cross-linking density resulting from the cross-linking agents.
