Month: December 2022

McKenna, Charles E. published the artcileFunctional selectivity in phosphonate ester dealkylation with bromotrimethylsilane, Category: bromides-buliding-blocks, the publication is Journal of the Chemical Society, Chemical Communications (1979), 739, database is CAplus.

The dealkylation reaction of Me₃SiBr with mixed alkyl carboxylate-phosphonate esters RP(O)(OEt)₂ (R = EtO₂C, EtO₂CCH₂, EtO₂CCH₂CH₂, MeO₂CCH₂CH₂) at 25° is highly selective for P-O silyl dealkylation. The reaction was extended to the selective preparation of trimethylsilyl amido-, alkynyl- and iodoalkylphosphonates in high yield, giving a simple route to phosphonic acids via hydrolysis of the phosphonates with neutral H₂O.

Journal of the Chemical Society, Chemical Communications published new progress about 66197-72-6. 66197-72-6 belongs to bromides-buliding-blocks, auxiliary class Aliphatic Chain, name is Diethyl (bromomethyl)phosphonate, and the molecular formula is C5H12BrO3P, Category: bromides-buliding-blocks.

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

Asawapirom, Udom published the artcileDialkylcyclopentadithiophene polymers and copolymers, Application In Synthesis of 111865-47-5, the publication is Macromolecular Rapid Communications (2001), 22(10), 746-749, database is CAplus.

Poly(2,6-(4,4-dialkyl)-4H-cyclopenta[2,1-b:3,4-b’]dithiophene) (PCPDT) homopolymers and poly[(2,7-(9,9-dialkyl)fluorene)-co-(2,6-(4,4-dialkyl)-4H-cyclopenta[2,1-b:3,4-b’]dithiophene)] (PF/PCPDT) copolymers have been synthesized according to Yamamoto with Ni(COD)₂ (or NiCl₂/Zn in the case of the homopolymer). PCPDT is characterized by a red-shifted long wavelength absorption maximum (565 nm) when compared to that of polyfluorene (PF, 378 nm). In contrast to PF, its heteroaromatic analog PCPDT does not form thermotropic LC phases. The PF/PCPDT copolymers show clear indications for a block copolymer character (two separated π-π^* absorption maxima, two glass transitions).

Macromolecular Rapid Communications 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 In Synthesis of 111865-47-5.

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

Roeven, Esther published the artcileDesign, Synthesis, and Characterization of Fully Zwitterionic, Functionalized Dendrimers, Product Details of C3H6BrNaO3S, the publication is ACS Omega (2019), 4(2), 3000-3011, database is CAplus and MEDLINE.

Dendrimers are interesting candidates for various applications because of the high level of control over their architecture, the presence of internal cavities, and the possibility for multivalent interactions. More specifically, zwitterionic dendrimers modified with an equal number of oppositely charged groups have found use in in vivo biomedical applications. However, the design and control over the synthesis of these dendrimers remains challenging, in particular with respect to achieving full modification of the dendrimer. In this work, we show the design and subsequent synthesis of dendrimers that are highly charged while having zero net charge, that is zwitterionic dendrimers that are potential candidates for biomedical applications. First, we designed and fully optimized the synthesis of charge-neutral carboxybetaine and sulfobetaine zwitterionic dendrimers. Following their synthesis, the various zwitterionic dendrimers were extensively characterized. In this study, we also report for the first time the use of XPS as an easy-to-use and quant. tool for the compositional anal. of this type of macromols. that can complement techniques such as NMR and gel permeation chromatog. Finally, we designed and synthesized zwitterionic dendrimers that contain a variable number of alkyne and azide groups that allow straightforward (bio)functionalization via click chem.

ACS Omega 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, Product Details of C3H6BrNaO3S.

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

Ishi-i, Tsutomu published the artcileReaction of [2.2]Metacyclophanes Having an Internal C:C Bond with Brominating Agents, Product Details of C10H16Br3N, the publication is Journal of Organic Chemistry (1996), 61(15), 5103-5108, database is CAplus.

Treatment of (I) 5-tert-butyl-8-ethenyl[2.2]metacyclophane with benzyltrimethylammonium tribromide or bromine exclusively gave an addition-elimination product II. The bromination reactions of (E)-5-tert-butyl-8-(2-phenylethenyl)[2.2]metacyclophane and its (Z)-isomer were always stereoconvergent to give a mixture (40/60) of β-bromoolefins. On the other hand, when (E)-8,8′-(ethene-1,2-diyl)bis(5-tert-butyl[2.2]metacyclophane) and its (Z)-isomer were treated with the brominating agents, none of the products arising from the electrophilic attack of a bromonium ion on the central etheno bridge was obtained. The reaction of (E)-8,8′-(ethene-1,2-diyl)bis(5-tert-butyl[2.2]metacyclophane) gave a monotetrahydropyrene derivative and a bis-tetrahydropyrene derivative, products resulting from a transannular reaction-alkenyl migration sequence. The reaction pathway of the brominations mentioned above is discussed.

Journal of Organic 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, Product Details of C10H16Br3N.

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

Lexa, Doris published the artcileOuter-sphere and inner-sphere processes in reductive elimination. Direct and indirect electrochemical reduction of vicinal dibromoalkanes, Application of 2,3-Dibromo-2,3-dimethylbutane, the publication is Journal of the American Chemical Society (1990), 112(17), 6162-77, database is CAplus.

The reduction of vicinal dibromo alkanes (OlX₂) is investigated as an example of the dichotomy between outer-sphere and inner-sphere processes in reductive elimination. As a result from the anal. of the kinetic data, outer-sphere reagents such as carbon electrodes and aromatic anion radicals react with vicinal dibromo alkanes according to an electron-transfer mechanism in which the rate-determining step is a concerted electron-transfer bond-breaking reaction leading to the β-bromoalkyl radical. The latter is then reduced very rapidly, in a second step, most probably along another concerted electron-transfer bond-breaking pathway leading directly to the olefin in the heterogeneous case and through halogen atom expulsion in the homogeneous case. In the absence of steric constraints, the reduction goes entirely through the antiperiplanar conformer because the resulting β-bromoalkyl radical is then stabilized by delocalization of the unpaired electron over the C-C-X framework due to a favorable interaction between the p_z orbital of the radical carbon and the σ^* orbital of the C-Br bond. This interaction is enhanced by alkyl substitution at the reacting carbons, resulting in an approx. linear correlation between the reduction potential and the C-X bond energy of OlX₂ on one hand and the vertical ionization potential of the olefin on the other. The stabilization energy is of the order of 0.2-0.3 eV for the anti conformers. It can also be taken as a measure of the rotation barrier around the C-C bond responsible for the loss of stereospecificity in the reduction This competes with the reduction of the two stable conformers of the OlX^• radicals and for the expulsion of the halogen atom. There is a remarkably good agreement between the ensuing prediction of the E:Z olefin ratio that should be found upon reduction of threo and erythro OlX₂ isomers by outer-sphere reagents such as aromatic anion radicals and the exptl. data. Although members of perfectly reversible redox couples, iron(I), iron(0), and cobalt(I) porphyrins offer typical examples of inner-sphere reagents in their reaction with vicinal dibromo alkanes. They indeed react much more rapidly than outer-sphere electron donors (aromatic anion radicals) of the same standard potential. On the basis of steric hindrance experiments, it was shown that they do not react according to an S_N2 rate-determining step involving the transient formation of an organometallic species. Complete stereospecificity is obtained, showing that they react along a halonium transfer E2 elimination mechanism rather than by an E1 elimination or a halogen atom transfer mechanism. As shown on a quant. basis, this is related to the large driving force offered to halonium abstraction by the strong affinity of the iron(III) and cobalt(III) complexes toward halide ions. In regard to catalysis, the investigated systems provide typical examples showing the superiority of inner-sphere (chem.) catalysis over outer-sphere (redox) catalysis of electrochem. reactions. Not only is the catalytic efficiency much better since the rate constants of the key steps are larger, given the standard potential of the catalyst, but also selectivity is dramatically improved.

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

Szostak, Michal published the artcileSelective Reduction of Barbituric Acids Using SmI₂/H₂O: Synthesis, Reactivity, and Structural Analysis of Tetrahedral Adducts, Recommanded Product: (4-Bromobut-1-yn-1-yl)trimethylsilane, the publication is Angewandte Chemie, International Edition (2013), 52(48), 12559-12563, database is CAplus and MEDLINE.

Monoredn. of barbituric acids using SmI₂ was reported. The radicals formed by one-electron reduction of the amide bond have been applied in intramol. additions to alkenes. The cyclic hemiaminal products are analogous to tetrahedral intermediates derived from amide addition reactions and are formed in a formal polarity reversal event.

Angewandte Chemie, International Edition 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 C10H15ClO3S, Recommanded Product: (4-Bromobut-1-yn-1-yl)trimethylsilane.

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

Farley, Conner M. published the artcileCatalytic [5 + 1]-Cycloadditions of Vinylcyclopropanes and Vinylidenes, Name: Cobalt(II) dibromo(1,2-dimethoxyethane), the publication is Journal of the American Chemical Society (2020), 142(10), 4598-4603, database is CAplus and MEDLINE.

Polysubstituted cyclohexenes bearing 1,3 (meta) substitution patterns are challenging to access using the Diels-Alder reaction (the ortho-para rule). Here, a cobalt-catalyzed reductive [5 + 1]-cycloaddition between a vinylcyclopropane and a vinylidene to provide methylenecyclohexenes bearing all-meta relationships has been reported. Vinylidene equivalent are generated from 1,1-dichloroalkenes using Zn as a stoichiometric reductant. Exptl. observations are consistent with a mechanism involving a cobaltacyclobutane formed from a [2 + 2]-cycloaddition between a cobalt vinylidene and a vinylcyclopropane.

Journal of the American Chemical Society published new progress about 18346-57-1. 18346-57-1 belongs to bromides-buliding-blocks, auxiliary class Cobalt, name is Cobalt(II) dibromo(1,2-dimethoxyethane), and the molecular formula is C4H10Br2CoO2, Name: Cobalt(II) dibromo(1,2-dimethoxyethane).

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

Pal, Rammyani published the artcileEfficient synthesis of 1,4-disubstituted triazolyl N-carboxamides via a simple and convenient MCR using basic alumina as solid support, Application of Bromo(1,10-phenanthroline)(triphenylphosphine)copper(I), the publication is Tetrahedron Letters (2013), 54(41), 5642-5646, database is CAplus.

A microwave assisted green protocol for the synthesis of 1,4-disubstituted triazolyl N-carboxamides was explored using basic alumina as solid support. The method allows domino Ullmann-type reaction, Click reaction and formation of ester or amide linkages in a single reaction vessel using Cu(phen)(PPh₃)Br and CMPA as catalyst and basic alumina as solid support in high yield. The protocol did not require addition of any external ligands or base. The method was also found to be equally good for the synthesis of bis triazole adducts.

Tetrahedron Letters published new progress about 25753-84-8. 25753-84-8 belongs to bromides-buliding-blocks, auxiliary class Copper, name is Bromo(1,10-phenanthroline)(triphenylphosphine)copper(I), and the molecular formula is C30H24BrCuN2P, Application of Bromo(1,10-phenanthroline)(triphenylphosphine)copper(I).

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

Chatterjee, Nivedita published the artcileAn approach toward the syntheses of triazolo benzoxazines, triazolo quinoxalines, triazolo benzodiazepines, triazolo benzoxazepines, and triazolo benzothiazines via a simple and convenient protocol using basic alumina as solid support, Category: bromides-buliding-blocks, the publication is Tetrahedron Letters (2014), 55(14), 2261-2265, database is CAplus.

A microwave-assisted green protocol for the syntheses of triazole-fused benzoxazines, benzoxazepines, quinoxalines, and benzothiazines I (R = aryl, 3-pyridyl; X = O, CO₂, NAc, NPh, S, CONH) was investigated using basic alumina as solid support. The one-pot reaction was carried out using Cu(phen)(PPh₃)Br as a catalyst. The protocol did not require the use of any addnl. ligands, base or the use of expensive and toxic palladium complexes.

Tetrahedron Letters published new progress about 25753-84-8. 25753-84-8 belongs to bromides-buliding-blocks, auxiliary class Copper, name is Bromo(1,10-phenanthroline)(triphenylphosphine)copper(I), and the molecular formula is C30H24BrCuN2P, Category: bromides-buliding-blocks.

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

Dhungana, Roshan K. published the artcileNi-Catalyzed Arylbenzylation of Alkenylarenes: Kinetic Studies Reveal Autocatalysis by ZnX₂, Category: bromides-buliding-blocks, the publication is Angewandte Chemie, International Edition (2021), 60(42), 22977-22982, database is CAplus and MEDLINE.

We report a Ni-catalyzed regioselective arylbenzylation of alkenylarenes with benzyl halides and arylzinc reagents. The reaction furnishes differently substituted 1,1,3-triarylpropyl structures that are reminiscent of the cores of oligoresveratrol natural products. The reaction is also compatible for the coupling of internal alkenes, secondary benzyl halides and variously substituted arylzinc reagents. Kinetic studies reveal that the reaction proceeds with a rate-limiting single-electron-transfer process and is autocatalyzed by in-situ-generated ZnX₂. The reaction rate is amplified by a factor of three through autocatalysis upon addition of ZnX₂.

Angewandte Chemie, International Edition 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, Category: bromides-buliding-blocks.

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