Tag: M.W=200-250

Manabe, Takao published the artcileNew Examples of 1,6- and 1,7-Hydrogen Transfer Promoted by an α-Silyl Group in Rhodium(I)-Catalyzed Radical Reactions of Acyclic Enediynes, SDS of cas: 69361-41-7, the publication is Organometallics (1998), 17(14), 2942-2944, database is CAplus.

A Rh(I) catalyst triggers cycloaromatization of ω-trialkylsilylated acyclic enediynes to afford benzosilacycloalkane or vinylsilane products via 1,6- and/or 1,7-H transfer, presumably effected by radical stabilization by an α-silyl moiety and via a seven- and/or eight-membered rhodacycle intermediate. The addition of a catalytic amount of di-Me maleate is essential to obtain better yields of the products.

Organometallics published new progress about 69361-41-7. 69361-41-7 belongs to bromides-buliding-blocks, auxiliary class PROTAC Linker,Aliphatic Linker, name is (4-Bromobut-1-yn-1-yl)trimethylsilane, and the molecular formula is C7H13BrSi, SDS of cas: 69361-41-7.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Di Yang published the artcileStudy on mechanism of a simple method to regulate salt tolerance of hydrophobically associating water-soluble polymers, Synthetic Route of 143-15-7, the publication is Colloids and Surfaces, A: Physicochemical and Engineering Aspects (2022), 128266, database is CAplus.

Salt tolerance is one of the important properties of hydrophobically associating water-soluble polymers (HAWSPs). In this work, HAWSPs with different hydrophobic monomer (M12) contents (0.3 mol% and 0.5 mol%) were synthesized. The viscosity of two polymers was measured. Mol. simulation (MS) were carried out to elucidate the salt tolerance mechanism. Results show that the polymer with a higher M12 content exhibits better salt tolerance. With increasing salt content, the radius of gyration of the polymers continuously decreases when M12 content is low, while it tends to increase and then decrease under high M12 contents. Combined with the spatial conformation, it can be found that only sufficient hydrophobic monomers can enhance the association effect of the polymers, forming more hydrophobic microregions and improving the viscosity. The radial distribution function results demonstrate the little effect of salt on hydrogen bonds. This work illustrates that simply adjusting the content of hydrophobic monomers is an effective strategy to regulate the salt tolerance of the polymers, which can significantly reduce the cost of salt-tolerant polymers.

Colloids and Surfaces, A: Physicochemical and Engineering Aspects published new progress about 143-15-7. 143-15-7 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic hydrocarbon chain, name is 1-Bromododecane, and the molecular formula is C12H25Br, Synthetic Route of 143-15-7.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Park, P. J. D. published the artcileThe infrared spectra of pressed-disk samples in relation to molecular structure in 2,3-dibromo-2,3-dimethylbutane, Computed Properties of 594-81-0, the publication is Chemical Communications (London) (1966), 557-8, database is CAplus.

The ir spectra of 2,3-dibromo-2,3-dimethylbutane (I) were determined for mull, crystal, dilute solution, liquid at high temperatures, and mull pressed-disk samples in order to clarify discrepancies between earlier spectroscopic and dipole-moment studies. The spectra of solid mull and crystal samples were in agreement with those reported previously. When the ir and Raman spectra of the crystal form were compared, the rule of mutual exclusion was found to apply. The crystal was entirely the trans form with mol. sym. C_2h. When the ir spectra of liquid I and dilute solutions were examined, addnl. weak absorption bands unreported previously were observed at 1283, 1263, 1190, 1055, 1020, 1005, 947, 925, 682, and 490 cm.^-1 These were assigned to the gauche isomer. Addnl. bands appeared also in the pressed-disk spectrum of I, corresponding almost exactly in frequency to those bands assigned to the gauche compound During the preparation of the pressed-disk samples, internal rotation was concluded to have occurred, with some mols. changing from the trans to the gauche form.

Chemical Communications (London) published new progress about 594-81-0. 594-81-0 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic hydrocarbon chain, name is 2,3-Dibromo-2,3-dimethylbutane, and the molecular formula is C6H12Br2, Computed Properties of 594-81-0.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Park, P. J. D. published the artcileSpectroscopic and acoustic studies on the rotational isomerism in 2,3-dibromo-2,3-dimethylbutane, Name: 2,3-Dibromo-2,3-dimethylbutane, the publication is Journal of the Chemical Society [Section] A: Inorganic, Physical, Theoretical (1968), 2064-7, database is CAplus.

The vibrational spectra of 2,3-dibromo-2,3-dimethylbutane (I) were measured in various phases. In the liquid phase, I exists as an equilibrium mixture of rotational isomers. A proposed frequency assignment of the gaucheand trans-isomers is given. A value of 6-7.5 kcal./mole was estimated for the energy of activation for the gauche → trans isomerization from acoustic measurements at ∼50°.

Journal of the Chemical Society [Section] A: Inorganic, Physical, Theoretical published new progress about 594-81-0. 594-81-0 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic hydrocarbon chain, name is 2,3-Dibromo-2,3-dimethylbutane, and the molecular formula is C6H12Br2, Name: 2,3-Dibromo-2,3-dimethylbutane.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Ma, Hao published the artcileEmulsifying stability and viscosity reduction for heavy crude oil in surfactant-polymer composite system, HPLC of Formula: 143-15-7, the publication is Journal of Molecular Liquids (2022), 119713, database is CAplus.

Heavy crude oil is one of the most precious and complex mol. mixtures available, with considerable economic relevance. Nevertheless, its high viscosity and complicated chem. compositions pose an exceptional challenge for viscosity reduction with a compound emulsification system in heavy oil exploitation. Here, two types of polymers were synthesized and compounded with surfactant SDS to reduce the heavy crude oil viscosity. Their emulsifying properties in demineralized water and mineralized water were measured to evaluate their differences from macroscopic views. Furthermore, the corresponding emulsion system (involving resins, asphaltenes, surfactants, polymers, etc.) was also simulated and computed using mol. dynamics simulation to investigate the relationships of various compositions on emulsifying properties at the mol. scale. The results showed that the surfactant-polymer composite system formed by the amphiphilic polymer had an obvious advantage in emulsifying stability with the water segregation rate of 60.6% after 48 h in the simulated salinity and the viscosity reduction rate reached more than 92.1% after optimization. Besides, the electrostatic interaction is the major part of the potential energy in emulsion systems at a ratio of 87.8%. The divalent cations (Ca²⁺ and Mg²⁺) resulted in the shrinkage or collapse of mol. conformation of the water-soluble polymer by 19%. The variation of interaction energy in salt solutions for different emulsifying systems caused a series of exptl. and simulated distinctions, such as solution viscosity, interface behaviors, the number of hydrogen bonds, and the spatial distribution function, which ultimately determined the emulsifying properties of heavy crude oil. Notably, this work offers insight into the interactions and influences of complex mixtures in oil-water systems. It also facilitates to design and apply the innovative functional chem. additives in heavy crude oil extraction and transportation.

Journal of Molecular Liquids published new progress about 143-15-7. 143-15-7 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic hydrocarbon chain, name is 1-Bromododecane, and the molecular formula is C12H25Br, HPLC of Formula: 143-15-7.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Brase, Stefan published the artcileIntramolecular Heck couplings and cycloisomerizations of bromodienes and enynes with 1′,1′-disubstituted methylenecyclopropane terminators: Efficient syntheses of [3]dendralenes, Application In Synthesis of 69361-41-7, the publication is European Journal of Organic Chemistry (2005), 4167-4178, database is CAplus.

2-Bromoalka-1,n-dienes, e.g. I, with tetrasubstituted methylenecyclopropane end groups, under palladium catalysis, underwent cyclization with cyclopropane-ring opening to give 2-ethenyl-3-methylene-1-cycloalkenes, e.g. II, which are substituted monocyclic [3]dendralenes. The same cross-conjugated trienes were isolated in good to excellent yields (77-92 %) from the corresponding 1,6- (e.g. III) and 1,7-enynes by a more atom-economic, palladium-catalyzed cycloisomerization. The vinylpalladium halide intermediate generated by initial carbopalladation of the 1,6-enyne III with in situ generated phenylpalladium iodide also underwent the same cyclization cascade to yield the correspondingly phenyl-substituted cyclic [3]dendralene. The palladium-catalyzed cycloisomerization of an alk-1-ene-7,12-diyne gave the bicyclic cross-conjugated tetraene. Key features of the mechanism of the palladium-catalyzed cycloisomerization were proved using a specially designed model system. Like other cyclic [3]dendralenes, the ethenyl(methylene)cycloheptene IV underwent a domino-Diels-Alder reaction with N-phenyltriazoline-3,5-dione to give a single diastereomer of the pentacyclic heterocycle.

European Journal of Organic Chemistry published new progress about 69361-41-7. 69361-41-7 belongs to bromides-buliding-blocks, auxiliary class PROTAC Linker,Aliphatic Linker, name is (4-Bromobut-1-yn-1-yl)trimethylsilane, and the molecular formula is C7H13BrSi, Application In Synthesis of 69361-41-7.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Stork, Gilbert published the artcileThe Total Synthesis of a Natural Cardenolide: (+)-Digitoxigenin, Product Details of C7H13BrSi, the publication is Journal of the American Chemical Society (1996), 118(43), 10660-10661, database is CAplus.

The authors report the total synthesis of natural (+)-digitoxigenin (I), the biol. active cardenolide which, as its trisaccharide derivative digitoxin, is one of the most frequently used of the active principles isolated from Digitalis species. I was prepared from chiral decalone II via octahydrophrenanthrenone III (TBS = Me₃CSiMe₂) and steroidal aldehyde IV.

Journal of the American Chemical Society published new progress about 69361-41-7. 69361-41-7 belongs to bromides-buliding-blocks, auxiliary class PROTAC Linker,Aliphatic Linker, name is (4-Bromobut-1-yn-1-yl)trimethylsilane, and the molecular formula is C17H37NO3, Product Details of C7H13BrSi.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Serra, Jordi published the artcileOxidant-Free Au(I)-Catalyzed Halide Exchange and C_sp2-O Bond Forming Reactions, COA of Formula: C7H8BBrO3, the publication is Journal of the American Chemical Society (2015), 137(41), 13389-13397, database is CAplus and MEDLINE.

Au has been demonstrated to mediate a number of organic transformations through the utilization of its π Lewis acid character, Au(I)/Au(III) redox properties or a combination of both. As a result of the high oxidation potential of the Au(I)/Au(III) couple, redox catalysis involving Au typically requires the use of a strong external oxidant. This study demonstrates unusual external oxidant-free Au(I)-catalyzed halide exchange (including fluorination) and C_sp2-O bond formation reactions utilizing a model aryl halide macrocyclic substrate. Addnl., the halide exchange and C_sp2-O coupling reactivity could also be extrapolated to substrates bearing a single chelating group, providing further insight into the reaction mechanism. This work provides the first examples of external oxidant-free Au(I)-catalyzed carbon-heteroatom cross-coupling reactions.

Journal of the American Chemical Society published new progress about 89694-44-0. 89694-44-0 belongs to bromides-buliding-blocks, auxiliary class Bromide,Boronic acid and ester,Benzene,Ether,Boronic Acids,Boronic acid and ester, name is 2-Bromo-5-methoxybenzene boronic acid, and the molecular formula is C14H10N2O, COA of Formula: C7H8BBrO3.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Han, Xue S. published the artcileSynthesis of high silicon content SAPO₄-5 using anionic surfactants in a hexanol/aqueous two phase media, Related Products of bromides-buliding-blocks, the publication is Chemical Communications (Cambridge, United Kingdom) (2002), 166-167, database is CAplus and MEDLINE.

High silicon content SAPO₄-5 (up to 0.511 atoms per unit cell) has been synthesized, using sodium 3-bromopropanesulfonate, sodium 1-butanesulfonate, sodium naphthalene-1-sulfonate or sodium n-decyl sulfate as surfactants; the SiO₂ in the reaction gels ranged up to 3.0 (molar ratio), silicon incorporation was confirmed by XRD, XRF, TG-DTA, FT-IR and SEM techniques.

Chemical Communications (Cambridge, United Kingdom) published new progress about 55788-44-8. 55788-44-8 belongs to bromides-buliding-blocks, auxiliary class Bromide,Salt,Aliphatic hydrocarbon chain,Aliphatic hydrocarbon chain, name is Sodium 3-bromopropane-1-sulfonate, and the molecular formula is C3H6BrNaO3S, Related Products of bromides-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary

Westphal, Eduard published the artcileReaching Room-Temperature Mesomorphism through Expansion of the Tristriazolotriazine Core with Alkoxybenzoate Units, Application of 1-Bromododecane, the publication is European Journal of Organic Chemistry (2022), 2022(29), e202200378, database is CAplus.

The tristriazolotriazine (TTT) N-heterocycle, despite being a relatively new mesogenic core for use in discotic liquid crystals, has already demonstrated its importance and promising characteristics. In this work, we extended the knowledge about the TTT, increasing the core size with alkoxybenzoate units, as well as evaluating how the expansion and number of peripheral chains affected the thermal and photophys. properties, both in solution and spin-coated films. Their thermal behavior and self-assembly were studied by differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction with synchrotron radiation, while the photophysics was investigated by UV-Vis absorption and fluorescence spectroscopy. The results show that, despite a considerable decrease in the fluorescence quantum yield with the core expansion, the mesomorphic properties are significantly enhanced, with two products showing Colh mesophase at room temperature, with large range of mesomorphism and very good thermal stability. It was also demonstrated how structural changes affected the self-assembly properties.

European Journal of Organic Chemistry published new progress about 143-15-7. 143-15-7 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic hydrocarbon chain, name is 1-Bromododecane, and the molecular formula is C15H18BF3O2, Application of 1-Bromododecane.

Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary