Tag: M.W=200-250

Booker-Milburn, Kevin I. published the artcileFe(III)/Cu(II) mediated 5- and 6-exo oxidative ring-expansion/cyclisation of cyclopropyl ethers: studies towards dictyol C and α-eudesmol, COA of Formula: C7H13BrSi, the publication is Tetrahedron Letters (2000), 41(23), 4651-4655, database is CAplus.

The outcome of oxidative ring-expansion/cyclization of cyclopropanes with a mixed Fe(III)/Cu(II) system was found to be dependent on the mode of cyclization. When 6-exo cyclization was attempted, unusual products resulting from oxidation of ring-opened primary radicals were obtained.

Tetrahedron Letters 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, COA of Formula: C7H13BrSi.

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

Mathew, Sanyo published the artcileEnhanced Helical Folding of ortho-Phenylenes through the Control of Aromatic Stacking Interactions, Recommanded Product: 2-Bromo-5-methoxybenzene boronic acid, the publication is Journal of the American Chemical Society (2014), 136(47), 16666-16675, database is CAplus and MEDLINE.

The ortho-phenylenes are a simple class of foldamers, with the formation of helixes driven by offset aromatic stacking interactions parallel to the helical axis. For the majority of reported o-phenylene oligomers, the perfectly folded conformer comprises perhaps 50-75% of the total population. Given the hundreds or thousands of possible conformers for even short oligomers, this distribution represents a substantial bias toward the folded state. However, “next-generation” o-phenylenes with better folding properties are needed if these structures are to be exploited as functional units within more complex architectures. Here, we report several new series of o-phenylene oligomers, varying both the nature and orientation of the substituents on every repeat unit. The conformational behavior was probed using a combination of NMR spectroscopy, DFT calculations, and X-ray crystallog. We find that increasing the electron-withdrawing character of the substituents gives oligomers with substantially improved folding properties. With moderately electron-withdrawing groups (acetoxy), we observe >90% of the perfectly folded conformer, and stronger electron withdrawing groups (triflate, cyano) give oligomers for which misfolded states are undetectable by NMR. The folding of these oligomers is only weakly solvent-dependent. General guidelines for the assessment of o-phenylene folding by NMR and UV-vis spectroscopy are also discussed.

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 C7H8BBrO3, Recommanded Product: 2-Bromo-5-methoxybenzene boronic acid.

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

Kropp, Paul J. published the artcileSurface-Mediated Reactions. 4. Hydrohalogenation of Alkynes, COA of Formula: C6H12Br2, the publication is Journal of Organic Chemistry (1994), 59(11), 3102-12, database is CAplus.

The use of appropriately prepared silica gel and alumina has been found to mediate the addition of hydrogen halides to alkynes. The technique has been rendered even more convenient by the use of various organic and inorganic acid halides that react in the presence of silica gel or alumina to generate hydrogen halides in situ. Treatment in this fashion of 1-propynylbenzene (1), which underwent no reaction in CH₂Cl₂ solution saturated with HCl, readily afforded the syn addition product alkenyl chloride (E)-PhCX:CHMe, [(E)-4, X = Cl]. On extended treatment (E)-4 (X = Cl) underwent subsequent isomerization to the thermodynamically more stable Z isomer. In a similar way bromides (E)- and (Z)-4 (X = Br) were obtained without competing formation of the radical products (E)- and (Z)-PhCH:CMeBr, which occurred in solution In contrast with slow solution-phase hydriodination of alkyne 1, surface-mediated addition readily afforded (E)-4 (X = I), followed by isomerization to the Z isomer. Equilibration E ⇌ Z of the alkenyl halides 4 was shown to involve, at least in part, addition-elimination via the gem-dihalides PhCX₂Et. Analogous behavior was exhibited by the phenylalkynes PhCCPh and PhCCCMe₃ on surface-mediated hydrohalogenation. Surface-mediated addition of HBr and HI to the internal alkylalkyne PrCCPr afforded principally the anti addition products (Z)-PrCX:CHPr. Treatment of the terminal alkynes BuCH₂CCH and Me₃CCCH with (COBr)₂ over alumina gave the dibromides, whereas use of acetyl bromide as the HBr precursor afforded the alkenyl bromides.

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, COA of Formula: C6H12Br2.

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

Lei, Ming published the artcileHomogeneous and Heterogeneous Pd-Catalyzed Selective C-P Activation and Transfer Hydrogenation for “Group-Substitution” Synthesis of Trivalent Phosphines, Synthetic Route of 143-15-7, the publication is Organic Letters (2022), 24(15), 2868-2872, database is CAplus and MEDLINE.

A group-substitution synthesis of trivalent phosphines via a C-P activation of phosphonium salts is reported. The alkyl groups were introduced by alkylation of phosphines to form phosphonium salts. The de-arylation of phosphonium salts was achieved by C-P activation and transfer hydrogenation with homogeneous or heterogeneous Pd (0) catalysts. With this method, trivalent phosphines were prepared from com. available triarylphosphines. A chiral monophosphine ligand could be prepared from BINAP in a de-phosphination process.

Organic Letters 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

Saha, Subhadeep published the artcileCoordination cage-based emulsifiers: templated formation of metal oxide microcapsules monitored by in situ LC-TEM, Synthetic Route of 143-15-7, the publication is Chemistry – A European Journal (2022), 28(5), e202103406, database is CAplus and MEDLINE.

Metallo-supramol. self-assembly has yielded a plethora of discrete nanosystems, many of which show competence in capturing guests and catalyzing chem. reactions. However, the potential of low-mol. bottom-up self-assemblies in the development of structured inorganic materials has rarely been methodically explored so far. Herein, we present a new type of metallo-supramol. surfactant with the ability to stabilize non-aqueous emulsions for a significant period. The mol. design of the surfactant is based on a heteroleptic coordination cage (CGA-3; CGA=Cage-based Gemini Amphiphile), assembled from two pairs of organic building blocks, grouped around two Pd(II) cations. Shape-complementarity between the differently functionalized components generates discrete amphiphiles with a tailor-made polarity profile, able to stabilize non-aqueous emulsions, such as hexadecane-in-DMSO. These emulsions were used as a medium for the synthesis of spherical metal oxide microcapsules (titanium oxide, zirconium oxide, and niobium oxide) from soluble, water-sensitive alkoxide precursors by allowing a controlled dosage of water to the liquid-liquid phase boundary. Synthesized materials were analyzed by a combination of electron microscopic techniques. In situ liquid cell transmission electron microscopy (LC-TEM) was utilized for the first time to visualize the dynamics of the emulsion-templated formation of hollow inorganic titanium oxide and zirconium oxide microspheres.

Chemistry – A European Journal 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

Zhou, Xinlian published the artcilePigeon egg white protein-based transparent durable hydrogel via monodisperse ionic surfactant-mediated protein condensation, Product Details of C12H25Br, the publication is Scientific Reports (2022), 12(1), 4633, database is CAplus and MEDLINE.

The thermal gelation property of proteins is useful in creating protein-based materials. The gelation of protein solution often proceeds by the random aggregation of denatured proteins, and the protein-based gels are typically brittle or opaque, or both. Improvement in the mech. and optical properties of protein-based materials are required for them to be practical and functional. This study investigated pigeon egg white, which is semitransparent in its thermally gelled state, as a protein source for creating hydrogel materials. The protein thermal gelation process was initiated from the orderly condensed state of proteins complexed with monodisperse ionic surfactants to suppress random aggregation. The resultant gel showed transparency in the visible light region and was not destroyed at 99% compression under 17.8 MPa compressive stress, 350-fold higher than the compressive fracture strength of typical boiled pigeon egg white. These results showed that durable transparent hydrogels could be fabricated by the rational combination of natural proteins and surfactants.

Scientific Reports 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 C8H5F3N4, Product Details of C12H25Br.

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

Chu, Haoke published the artcileAsymmetric Dearomatization of Indole by Palladium/PC-Phos-Catalyzed Dynamic Kinetic Transformation, Product Details of C7H8BBrO2, the publication is Angewandte Chemie, International Edition (2020), 59(49), 21991-21996, database is CAplus and MEDLINE.

A palladium-catalyzed intermol. dynamic kinetic asym. dearomatization of 3-arylindoles with internal alkynes was developed with the use of achiral Xantphos and chiral sulfinamide phosphine ligand (PC-Phos) as the co-ligands. This method could deliver various spiro[indene-1,3′-indole] compounds in good yields (up to 95% yield) with up to 98% ee. The salient features of the transformation include the use of readily available substrates, ease of scale-up and the versatile functionalization of the products. The mechanistic experiments gave some insights on active intermediates.

Angewandte Chemie, International Edition published new progress about 1450711-53-1. 1450711-53-1 belongs to bromides-buliding-blocks, auxiliary class Bromide,Boronic acid and ester,Benzene,Boronic Acids,Boronic Acids,Boronic acid and ester, name is (2-Bromo-5-methylphenyl)boronic acid, and the molecular formula is C7H8BBrO2, Product Details of C7H8BBrO2.

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

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

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