Month: November 2022

Kim, Duk-Ki published the artcileSimple bromination of activated arenes by IBX amide resin and tetraethylammonium bromide, Related Products of bromides-buliding-blocks, the publication is Synlett (2005), 279-282, database is CAplus.

A mild and operationally simple method of brominating activated aromatic compounds using a polymer supported IBX reagent (IBX amide resin) and tetraethylammonium bromide (TEAB) was developed. The activated aromatics, when reacted with IBX amide resin in the presence of TEAB, were easily converted into the brominated aromatics in high yields at room temperature

Synlett published new progress about 1998-61-4. 1998-61-4 belongs to bromides-buliding-blocks, auxiliary class Fluoride,Bromide,Benzene,Phenol, name is 4-Bromo-2,3,5,6-tetrafluorophenol, and the molecular formula is C6HBrF4O, Related Products of bromides-buliding-blocks.

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

Lim, Chang Su published the artcileA two-photon turn-on probe for glucose uptake, COA of Formula: C12H16BBrO2, the publication is Chemical Communications (Cambridge, United Kingdom) (2012), 48(15), 2122-2124, database is CAplus and MEDLINE.

The authors report a two-photon turn-on probe (AS1) that can be excited by 780 nm femto-second pulses and visualize glucose uptake and the changes in the intracellular glucose concentration in live cells and tissue by two-photon microscopy.

Chemical Communications (Cambridge, United Kingdom) published new progress about 166821-88-1. 166821-88-1 belongs to bromides-buliding-blocks, auxiliary class Bromide,Boronic acid and ester,Benzyl bromide,Benzene,Boronic Acids,Boronic acid and ester, name is 2-(2-(Bromomethyl)phenyl)-5,5-dimethyl-1,3,2-dioxaborinane, and the molecular formula is C12H16BBrO2, COA of Formula: C12H16BBrO2.

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

Chu, Edith Ju-Hwa published the artcileSymmetrical diaryldialkylethanediols. I. 2,3-Diphenyl-2,3-butanediol, Application of 2,3-Dibromo-2,3-dimethylbutane, the publication is Journal of the Chinese Chemical Society (Peking) (1942), 190-5, database is CAplus.

Bz₂ (0.0642 g. mol.) was added to 100 cc. of anhydrous Et₂O containing the Grignard reagent prepared from 0.37 g. mol. of Mg and 0.264 g. mol. of MeI. After the vigorous reaction had subsided, the mixture was refluxed for 3 hrs. and then hydrolyzed with 40 g. of NH₄Cl in 200 cc. cold H₂O. The crude 2,3-diphenyl-2,3-butanediol (I) was extracted from the reaction mixture with Et₂O and C₆H₆ and crystallized from alc., m. 118° (52% yield). Distillation of the mother liquor yielded α-methyl-α-phenylpropiophenone (II), m. 45° b. 307°. An alternative method for preparing I was to dissolve 0.036 g. mol. of PhCOMe (III) in 20 cc. of iso-PrOH and expose to sunlight for 1 month. After removal of the solvent, a quant. yield of a mixture of the high-and low-melting modifications of I was obtained, m. 84° (not sharp). A separation of the modifications was effected by fractional crystallization from CCl₄, the high-melting modification being less soluble Poor yields of I were obtained when III was reduced with Na or Mg amalgam. I (0.0144 g. mol.) was boiled with 5 cc. of HOAc containing a few crystals of iodine for 1 hr. The reaction mixture was poured into aqueous NaHSO₃ and extracted with Et₂O. From the Et₂O, II was obtained in 89% yield, m. 41-2° b₆₁₀ 300-1°. Oxime, m. 151.2-2.2° (from alc.). I (0.0023 g. mol.) refluxed with 5 cc. of Ac₂O for 1.5 hrs. yielded a mixture of II and unreacted I.

Journal of the Chinese Chemical Society (Peking) 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, Application of 2,3-Dibromo-2,3-dimethylbutane.

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

Dubois, Jacques-Emile published the artcileReactivity of methyl-substituted ethylenebromonium ions. Correlation between charge distribution and regio- or chemoselectivity, Application of 2,3-Dibromo-2,3-dimethylbutane, the publication is Journal of the American Chemical Society (1978), 100(11), 3506-13, database is CAplus.

The opening of 7 Me-substituted bromonium ions by competitive nucleophilic attack with MeOH and Br^– in MeOH containing 0.2 M NaBr was studied. In each case the dibromoalkane and the bromomethoxyalkane (and its anti-Markovnikov isomer are formed. Chemoselectivity, expressed as % bromomethoxyalkane, varies from 38-84.7%, but does not vary linearly with the number of Me groups. This nonadditivity comes from the role played by Br in the charge distribution on C sites in the ethylenebromonium ion. This charge distribution is evaluated from Olah’s measurements of ¹³C NMR shifts of these ions stabilized in a superacid medium. Chemoselectivity correlates with the charge distribution on the C atom to which the MeO group is attached. The regioselectivity of this attack depends on the difference in the free enthalpies of activation leading to MeO isomers, and correlates with differences in charge distributions on the 2 C atoms.

Journal of the American Chemical Society 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, Application of 2,3-Dibromo-2,3-dimethylbutane.

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

Aakeroy, Christer B. published the artcileEstablishing a Hierarchy of Halogen Bonding by Engineering Crystals without Disorder, Safety of 4-Bromo-2,3,5,6-tetrafluorophenol, the publication is Crystal Growth & Design (2013), 13(9), 4145-4150, database is CAplus.

It has been shown, using a foundation of new structural data, that the relative strength and capability of iodo- and bromo-based mols. to act as halogen-bond donors in a competitive supramol. arena accurately reflect a ranking of halogen-bond donors based upon electrostatic mol. potentials. Furthermore, to obtain the critical structural information, a protocol (comprising a lowering of mol. symmetry and the addition of strong and directional hydrogen bonds) for engineering crystals without positional disorder was successfully developed.

Crystal Growth & Design published new progress about 1998-61-4. 1998-61-4 belongs to bromides-buliding-blocks, auxiliary class Fluoride,Bromide,Benzene,Phenol, name is 4-Bromo-2,3,5,6-tetrafluorophenol, and the molecular formula is C6HBrF4O, Safety of 4-Bromo-2,3,5,6-tetrafluorophenol.

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

Kuivila, Henry G. published the artcileElimination and substitution in the reactions of vicinal dihalides and oxyhalides trimethylstanoylsodium. Effects of solvent and of ion aggregation on course and stereochemistry, HPLC of Formula: 594-81-0, the publication is Journal of Organic Chemistry (1979), 44(26), 4774-81, database is CAplus.

Vicinal dihalides react with Me₃SNa via anti stereochem. to produce the corresponding alkenes in nearly quant. yields; MeOCHMeCHBrMe yields both elimination and substitution (MeOCHMeCHMeSnMe₃) products. The stereochem. is predominantly syn when THF is the solvent, and elimination predominates. When tetraglyme is the solvent, substitution is the predominant reaction; the stereochem. of both substitution and elimination is nonspecific. The mechanistic implications of these observations are considered.

Journal of Organic Chemistry 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, HPLC of Formula: 594-81-0.

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

Song, Jung-Ah published the artcileSeven-Membered Ring-Forming Cyclopolymerization of 1,8-Nonadiyne Derivatives Using Grubbs Catalysts: Rational Design of Monomers and Insights into the Mechanism for Olefin Metathesis Polymerizations, Recommanded Product: (4-Bromobut-1-yn-1-yl)trimethylsilane, the publication is Macromolecules (Washington, DC, United States) (2017), 50(7), 2724-2735, database is CAplus.

Studies into the cyclopolymn. (CP) of diyne derivatives using metal carbenes have focused on the formation of five- and six-membered rings because these small rings can be easily synthesized while the preparation of medium-sized seven-membered rings are more difficult. For the first time, we achieved the CP forming challenging seven-membered rings as repeat units using Grubbs catalysts by novel design of 1,8-nonadiyne monomers. The key to the successful CP was the introduction of the appropriate aminal and acetal groups, which have short C-N and C-O bonds, and low rotational barriers, thus greatly enhancing the cyclization efficiency. During our mechanistic investigation, we directly observed an actual 14-electron Ru propagating carbene by ¹H NMR spectroscopy for the first time during olefin metathesis reaction, presumably because the great steric hindrance from the propagating carbene containing a larger seven-membered ring than five- or six-membered ring retarded the coordination of ligands. We also observed decomposition of the catalysts to ruthenium hydrides during polymerization for the first time. Kinetic studies revealed three interesting features of this 1,8-nonadiyne CP: (1) in contrast to conventional polymerizations, the rate-determining step for the CP of 1,8-nonadiynes was the cyclization step; (2) the intrinsic reactivity of the acetal monomers was higher than that of the aminal monomers; but (3) the overall polymerization efficiency of the aminal monomers was higher than that of the acetal monomers because of the higher stability of their carbenes. Finally, we achieved a controlled CP of the aminal monomers using a fast-initiating third-generation Grubbs catalyst. This allowed the synthesis of not only the diblock copolymer containing five- and seven-membered rings but also the triblock copolymer containing five-, six-, and seven-membered rings.

Macromolecules (Washington, DC, United States) 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 C65H82N2O18S2, Recommanded Product: (4-Bromobut-1-yn-1-yl)trimethylsilane.

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

Song, Jeong Uk published the artcileDesign and synthesis of novel 2-(indol-5-yl)thiazole derivatives as xanthine oxidase inhibitors, Category: bromides-buliding-blocks, the publication is Bioorganic & Medicinal Chemistry Letters (2015), 25(6), 1254-1258, database is CAplus and MEDLINE.

Xanthine oxidase (XO) inhibitors were widely used for the treatment of gout. Indole rings are frequently used as active scaffold in designing inhibitors for enzymes. Herein, the authors describe the structure-activity relation for novel xanthine oxidase inhibitors based on indole scaffold. A series of novel tri-substituted 2-(indol-5-yl)thiazole derivatives were synthesized, and their in vitro inhibitory activities against xanthine oxidase and in vivo efficacy lowering uric acid level in blood were measured. Among them, 2-(3-cyano-2-isopropylindol-5-yl)-4-methylthiazole-5-carboxylic acid exhibits the most potent XO inhibitory activity (IC₅₀ value: 3.5 nM) and the excellent plasma uric acid lowering activity. Study of structure activity relation indicated that hydrophobic moiety (e.g., isopropyl) at 1-position and electron withdrawing group (e.g., CN) at 3-position of indole ring and small hydrophobic group (CH₃) at 4-position of the thiazole ring enhanced the XO inhibitory activity. Hydrophobic substitution such as iso-Pr at 1-position of the indole moiety without any substitution at 2-position has an essential role for enhancing bioavailability and therefore for high in vivo efficacy.

Bioorganic & Medicinal Chemistry Letters published new progress about 16523-02-7. 16523-02-7 belongs to bromides-buliding-blocks, auxiliary class Bromide,Sulfone,Aliphatic hydrocarbon chain, name is 2-Bromoethyl Methyl Sulfone, and the molecular formula is C2H2N4O2, Category: bromides-buliding-blocks.

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

Isobe, Hiroyuki published the artcileSynthesis of Fullerene Glycoconjugates via a Copper-Catalyzed Huisgen Cycloaddition Reaction, Recommanded Product: 7-Bromohept-1-yne, the publication is Organic Letters (2007), 9(22), 4611-4614, database is CAplus and MEDLINE.

The synthesis of fullerene-carbohydrate conjugates using a copper-catalyzed [3 + 2] cycloaddition reaction to facilitate the union of an azido- functionalized sugar and a pentaalkynyl[60]fullerene is reported. Fullerenes bearing five oligosaccharides such as globotriaosylceramide (Gb3)-trisaccharide can be readily accessed. Nanometer-scale mol. architectures presenting as many as 15 sugar moieties in C₅-symmetry are readily produced. The cycloaddition reaction proceeds quant. under mild conditions without the need to protect the sugar hydroxyl groups.

Organic Letters published new progress about 81216-14-0. 81216-14-0 belongs to bromides-buliding-blocks, auxiliary class Linker,PROTAC Linker, name is 7-Bromohept-1-yne, and the molecular formula is C7H11Br, Recommanded Product: 7-Bromohept-1-yne.

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

Nahakpam, Lokendrajit published the artcilePolymer-Supported Tribromide as a New Solid Phase and Recyclable Catalyst for the Synthesis of 2-(N-Arylamino)benzothiazoles Under Solvent-Free Microwave Irradiation Conditions, Application of Mono(N,N,N-trimethyl-1-phenylmethanaminium) tribromide, the publication is Journal of Heterocyclic Chemistry (2015), 52(1), 267-272, database is CAplus.

The solid-phase synthesis of 2-(N-arylamino)benzothiazoles I (R¹ = H, 4-CH₃, 5-CH₃, 4-OCH₃; R² = H, 2-CH₃, 4-Cl, etc.) was achieved by reacting substituted thioureas with polymer-supported tribromide in high yield under microwave irradiation The method has several advantages such as short reaction time, good yields, and environmentally benign procedure. The catalyst could be recovered conventionally and reused at least four times without loss of its activity.

Journal of Heterocyclic Chemistry published new progress about 111865-47-5. 111865-47-5 belongs to bromides-buliding-blocks, auxiliary class Benzenes, name is Mono(N,N,N-trimethyl-1-phenylmethanaminium) tribromide, and the molecular formula is C10H16Br3N, Application of Mono(N,N,N-trimethyl-1-phenylmethanaminium) tribromide.

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