4462-96-8Relevant academic research and scientific papers
Hydrogenated Poly(Dewar benzene): A Compact Cyclic Olefin Polymer with Enhanced Thermomechanical Properties
Bielawski, Christopher W.,Lee, Stanfield Y.,Seo, Jinwon
, (2020)
Dihydro Dewar benzene(bicyclo[2.2.0]hex-2-ene) was synthesized and polymerized using the Grubbs third generation catalyst. The corresponding ring-opening metathesis polymerization proceeded in a controlled manner, as determined by a linear relationship between the molecular weight of the polymer produced and the monomer-To-catalyst feed ratio as well as an ability to extend polymer chains through exposure to an additional monomer. Subsequent treatment with tosylhydrazide afforded the corresponding hydrogenated derivative. The hydrogenated polymer was found to exhibit high melting and decomposition temperatures as well as a relatively high Young's modulus when compared to other polyolefins [e.g., hydrogenated poly(norbornene) and poly(ethylene)]. The enhanced thermal and mechanical properties were found to originate from a relatively low phase transition entropy combined with high polymer crystallinity, features that were attributed to restricted bond rotation within the repeating units of the hydrogenated polymer.
Development and Execution of a Production-Scale Continuous [2 + 2] Photocycloaddition
Beaver, Matthew G.,Zhang, En-Xuan,Liu, Zhi-Qing,Zheng, Song-Yuan,Wang, Bin,Lu, Jiang-Ping,Tao, Jian,Gonzalez, Miguel,Jones, Sian,Tedrow, Jason S.
, p. 2139 - 2146 (2020/06/05)
This article details the approach to large-scale production of cyclobutane 2 by the continuous-flow [2 + 2] photocycloaddition of maleic anhydride and ethylene, including (1) focused reaction optimization and development of a robust isolation protocol, (2) the approach to equipment design and process safety, and (3) the results of commissioning tests and production runs delivering the target compound at throughputs exceeding 5 kg/day.
Phosphodiesterase inhibitor and applications thereof
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Paragraph 0053-0057, (2020/01/12)
The invention belongs to the technical field of medicines, particularly relates to phosphodiesterase inhibitor compounds shown as formula (I), or pharmaceutically acceptable salts and stereoisomers thereof, and further relates to pharmaceutical preparations and pharmaceutical compositions of the compounds and application of the pharmaceutical preparations and the pharmaceutical compositions. In the formula (I), R1 and R2 are defined in the specification. The compounds provided by the invention can be used for preparing medicines for treating or preventing related diseases mediated by PDE9 kinase.
Finding the Perfect Match: A Combined Computational and Experimental Study toward Efficient and Scalable Photosensitized [2 + 2] Cycloadditions in Flow
Williams, Jason D.,Nakano, Momoe,Gérardy, Romaric,Rincón, Juan A.,De Frutos, óscar,Mateos, Carlos,Monbaliu, Jean-Christophe M.,Kappe, C. Oliver
supporting information, p. 78 - 87 (2019/01/24)
With ever-evolving light-emitting diode (LED) technology, classical photochemical transformations are becoming accessible with more efficient and industrially viable light sources. In combination with a triplet sensitizer, we report the detailed exploration of [2 + 2] cycloadditions, in flow, of various maleic anhydride derivatives with gaseous ethylene. By the use of a flow reactor capable of gas handling and LED wavelength/power screening, an in-depth optimization of these reactions was carried out. In particular, we highlight the importance of matching the substrate and sensitizer triplet energies alongside the light source emission wavelength and power. Initial triplet-sensitized reactions of maleic anhydride were hampered by benzophenone's poor absorbance at 375 nm. However, density functional theory (DFT) calculations predicted that derivatives such as citraconic anhydride have low enough triplet energies to undergo triplet transfer from thioxanthone, whose absorbance matches the LED emission at 375 nm. This observation held true experimentally, allowing optimization and further exemplification in a larger-scale reactor, whereby >100 g of material was processed in 10 h. These straightforward DFT calculations were also applied to a number of other substrates and showed a good correlation with experimental data, implying that their use can be a powerful strategy in targeted reaction optimization for future substrates.
Finding the Perfect Match: A Combined Computational and Experimental Study toward Efficient and Scalable Photosensitized [2 + 2] Cycloadditions in Flow
Williams, Jason D.,Nakano, Momoe,Gérardy, Romaric,Rincón, Juan A.,De Frutos, óscar,Mateos, Carlos,Monbaliu, Jean-Christophe M.,Kappe, C. Oliver
supporting information, (2019/01/21)
With ever-evolving light-emitting diode (LED) technology, classical photochemical transformations are becoming accessible with more efficient and industrially viable light sources. In combination with a triplet sensitizer, we report the detailed exploration of [2 + 2] cycloadditions, in flow, of various maleic anhydride derivatives with gaseous ethylene. By the use of a flow reactor capable of gas handling and LED wavelength/power screening, an in-depth optimization of these reactions was carried out. In particular, we highlight the importance of matching the substrate and sensitizer triplet energies alongside the light source emission wavelength and power. Initial triplet-sensitized reactions of maleic anhydride were hampered by benzophenone's poor absorbance at 375 nm. However, density functional theory (DFT) calculations predicted that derivatives such as citraconic anhydride have low enough triplet energies to undergo triplet transfer from thioxanthone, whose absorbance matches the LED emission at 375 nm. This observation held true experimentally, allowing optimization and further exemplification in a larger-scale reactor, whereby >100 g of material was processed in 10 h. These straightforward DFT calculations were also applied to a number of other substrates and showed a good correlation with experimental data, implying that their use can be a powerful strategy in targeted reaction optimization for future substrates.
LADDERANE LIPID COMPOUNDS AND LIPOSOMES AND METHODS OF PREPARING AND USING THE SAME
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Page/Page column 51; 52, (2018/03/25)
Methods for preparing a variety of ladderane precursors, ladderane compounds and ladderane lipids are provided. Also provided are methods of preparing a liposome from the ladderane lipids disclosed herein, and compositions thereof. Aspects of the invention include encapsulated one or more cargo moieties in the liposome or compositions thereof and use of the subject liposome compositions as vehicles in drug delivery, imaging, diagnostics and other medical applications. Aspects of the methods disclosed herein include administering a liposomal composition comprising a pharmaceutical agent to a subject under conditions sufficient to deliver the composition to a site of interest in the subject, and release the pharmaceutical agent from the liposomal composition.
Chemical Synthesis and Self-Assembly of a Ladderane Phospholipid
Mercer, Jaron A. M.,Cohen, Carolyn M.,Shuken, Steven R.,Wagner, Anna M.,Smith, Myles W.,Moss, Frank R.,Smith, Matthew D.,Vahala, Riku,Gonzalez-Martinez, Alejandro,Boxer, Steven G.,Burns, Noah Z.
supporting information, p. 15845 - 15848 (2016/12/23)
Ladderane lipids produced by anammox bacteria constitute some of the most structurally fascinating yet poorly studied molecules among biological membrane lipids. Slow growth of the producing organism and the inherent difficulty of purifying complex lipid mixtures have prohibited isolation of useful amounts of natural ladderane lipids. We have devised a highly selective total synthesis of ladderane lipid tails and a full phosphatidylcholine to enable biophysical studies on chemically homogeneous samples of these molecules. Additionally, we report the first proof of absolute configuration of a natural ladderane.
NOVEL HEPATITIS C VIRUS INHIBITORS
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Page/Page column 80, (2013/07/05)
The invention provides compounds of formula (I): wherein Rings A and A' are independently 5-membered optionally substituted aromatic heterocycles; Q is C(=O)NR1R1' or formula U is C(R4)2, O, S, S(=O)2, C(R4)2C(R4)2, CH2O, OCH2, CH2S, SCH2, CH2S(=O)2, S(=O)CH2 or C=C(Ru )2; X is CH2, CHR12, CR12R12, O, S, S(=O)2 or NRx; m is 0, 1, 2 or 3; n is 0, 1, 2 or 3; the other variables are as defined in the claims, which are of use in the treatment or prophylaxis of hepatitis C virus infection, and related aspects.
Structure-mechanochemical activity relationships for cyclobutane mechanophores
Kryger, Matthew J.,Munaretto, Alexander M.,Moore, Jeffrey S.
supporting information; experimental part, p. 18992 - 18998 (2012/02/05)
Ultrasound activation of mechanophores embedded in polymer backbones has been extensively studied of late as a method for realizing chemical reactions using force. To date, however, there have been few attempts at systematically investigating the effects of mechanophore structure upon rates of activation by an acoustic field. Herein, we develop a method for comparing the relative reactivities of various cyclobutane mechanophores. Through the synthesis and ultrasonic irradiation of a molecular weight series of poly(methyl acrylate) polymers in which each macromolecule has a single chain-centered mechanophore, we find measurable and statistically significant shifts in molecular weight thresholds for mechanochemical activation that depend on the structure of the mechanophore. We also show that calculations based on the constrained geometries simulate external force method reliably predict the trends in mechanophore reactivity. These straightforward calculations and the experimental methods described herein may be useful in guiding the design and the development of new mechanophores for targeted applications.
Synthesis of the constrained glutamate analogues (2S,1′R,2′R)- and (2S,1′S,2′S)-2-(2′-carboxycyclobutyl)glycines L-CBG-II and L-CBG-I by enzymatic transamination
Gu, Xin,Xian, Mo,Roy-Faure, Sophie,Bolte, Jean,Aitken, David J.,Gefflaut, Thierry
, p. 193 - 196 (2007/10/03)
Optically pure trans-cyclobutane analogues of glutamic acid are prepared by highly selective enzymatic transamination of a single racemic trans-cyclobutane α-ketoglutaric acid derivative 5, which is synthesized in five steps from maleic anhydride. (2S,1′R,2′R)- and (2S,1′S,2′S)-2- (2′-carboxycyclobutyl)glycines L-CBG-II and L-CBG-I are obtained using aspartate aminotransferase (AAT) and branched chain aminotransferase (BCAT), respectively.
