Month: January 2023

Central cholinergic agents. I. Potent acetylcholinesterase inhibitors, 2-[ω-[N-alkyl-N-(ω-phenylalkyl)amino]alkyl]-1H-isoindole-1,3(2H)-diones, based on a new hypothesis of the enzyme’s active site was written by Ishihara, Yuji;Kato, Koki;Goto, Giichi. And the article was included in Chemical & Pharmaceutical Bulletin in 1991.Category: bromides-buliding-blocks This article mentions the following:

It has been suggested that the active site of acetylcholinesterase contains a hydrophobic binding site (HBS-1), which is closely adjacent to both the anionic and the esteratic sites. In this paper, we assumed that there exists another hydrophobic binding site (HBS-2), some distance removed from the anionic site. On this assumption, a new working hypothesis was proposed for the design of acetylcholinesterase inhibitors. A series of 2-[ω-[N-alkyl-N-(ω-phenylalkyl)amino]alkyl]-1H-isoindole-1,3(2H)-diones (I, X = e.g., O₂N, OH, Me, Cl, amino group, or COPh, Y = e.g., H, halo OMe, R = H or alkyl, n = 3-9, m = 1-4) was designed based on this hypothesis and tested for its inhibitory activities on acetylcholinesterase. Some in this series were revealed to be more potent than physostigmine. Optimum activity was found to be associated with a five carbon chain length separating the benzylamino group from the 1H-isoindole-1,3(2H)-dione (phthalimide) moiety. Quant. study of substitution effect on the phthalimide moiety revealed that hydrophilic and electron-withdrawing groups enhance the activity. In the experiment, the researchers used many compounds, for example, N-(5-Bromopentyl)phthalimide (cas: 954-81-4Category: bromides-buliding-blocks).

N-(5-Bromopentyl)phthalimide (cas: 954-81-4) belongs to organobromine compounds. Bromo compounds are employed in a variety of metal-catalyzed coupling reactions. They are also ideal candidates for the synthesis of Grignard reagents that have wide-applicability in organic synthesis. Commercially available organobromine pharmaceuticals include the vasodilator nicergoline, the sedative brotizolam, the anticancer agent pipobroman, and the antiseptic merbromin. Category: bromides-buliding-blocks

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary

Nickel-Catalyzed Reductive Cross-Coupling of Alkyl Bromides and Chlorosilanes was written by Xing, Mimi;Cui, Huanhuan;Zhang, Chun. And the article was included in Organic Letters in 2021.Synthetic Route of C10H13BrO This article mentions the following:

A novel nickel-catalyzed highly selective reductive cross-coupling of alkyl bromides and chlorosilanes to construct the C-Si bond has been developed. Under benign reaction conditions, a series of structurally interesting organosilanes can be accessed without Ni-catalyzed isomerization. The utility of this chem. is illustrated by further transformations of the product. Moreover, the radical mechanism of the reaction is illustrated by control experiments In the experiment, the researchers used many compounds, for example, 1-(3-Bromopropyl)-4-methoxybenzene (cas: 57293-19-3Synthetic Route of C10H13BrO).

1-(3-Bromopropyl)-4-methoxybenzene (cas: 57293-19-3) belongs to organobromine compounds. Bromo compounds are employed in a variety of metal-catalyzed coupling reactions. They are also ideal candidates for the synthesis of Grignard reagents that have wide-applicability in organic synthesis. alpha-Bromoesters are employed in the Reformatsky reaction for the synthesis of beta-hydroxyesters. The principal reactions for organobromides include dehydrobromination, Grignard reactions, reductive coupling, and nucleophilic substitution.Synthetic Route of C10H13BrO

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary

A simple and efficient in situ generated ruthenium catalyst for chemoselective transfer hydrogenation of nitroarenes: kinetic and mechanistic studies and comparison with iridium systems was written by Paul, Bhaskar;Chakrabarti, Kaushik;Shee, Sujan;Maji, Milan;Mishra, Anju;Kundu, Sabuj. And the article was included in RSC Advances in 2016.Safety of 2-Bromo-1,10-phenanthroline This article mentions the following:

The catalytic activities of a series of in-situ generated homogeneous ruthenium systems based on com. available [RuCl₂(p-cymene)]₂ and various ligands in transfer hydrogenation of nitroarenes to anilines were investigated. Combination of [RuCl₂(p-cymene)]₂ and tridentate phenanthroline based ligand 2-(6-methoxypyridin-2-yl)-1,10-phenanthroline (phenpy-OMe) exhibited the highest catalytic activity for this reaction using 2-propanol as hydrogen source. This protocol provided a facile route to access aromatic amines under mild conditions in excellent yields. Notably, this system chemoselectively reduced the nitro groups over an array of other reactive functionalities such as ketone, alkene, amide, nitrile, and aryl halide. Operational simplicity, high yields, mild reaction conditions and short reaction times make this an attractive methodol. for accessing various functionalized anilines. A series of controlled experiments and careful mechanistic investigation with the possible intermediates suggested that transformation of nitrobenzene to aniline with ruthenium and iridium system proceeded via direct route and condensation route resp. In the experiment, the researchers used many compounds, for example, 2-Bromo-1,10-phenanthroline (cas: 22426-14-8Safety of 2-Bromo-1,10-phenanthroline).

2-Bromo-1,10-phenanthroline (cas: 22426-14-8) belongs to organobromine compounds. Bromo compounds are employed in a variety of metal-catalyzed coupling reactions. They are also ideal candidates for the synthesis of Grignard reagents that have wide-applicability in organic synthesis. Bromine-containing agents predominate because not only are they more efficient than similar chlorine-containing species, but also the high atomic weight of bromine ensures that it is present in a high mass fraction within most organobromine compounds.Safety of 2-Bromo-1,10-phenanthroline

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary

Scandium-bipyridine-catalyzed enantioselective aminolysis of meso-epoxides was written by Mai, Enzo;Schneider, Christoph. And the article was included in Chemistry – A European Journal in 2007.Safety of Isopentyltriphenylphosphonium bromide This article mentions the following:

The scandium-bipyridine-catalyzed enantioselective addition of anilines and O-alkyl hydroxylamines to meso-epoxides has been optimized and extended to a broad range of epoxides and amines. Whereas aromatic meso-epoxides generally furnished the corresponding 1,2-amino alcs., e.g., I, in excellent enantioselectivities, aliphatic meso-epoxides only gave rise to moderate enantioselectivities in the aminolysis. The catalyst loading may be lowered to just 5 mol% with only marginal effects on yield and enantioselectivity. A strong pos. nonlinear effect has been observed, pointing to aggregation phenomena of the catalyst. In the experiment, the researchers used many compounds, for example, Isopentyltriphenylphosphonium bromide (cas: 28322-40-9Safety of Isopentyltriphenylphosphonium bromide).

Isopentyltriphenylphosphonium bromide (cas: 28322-40-9) belongs to organobromine compounds. Organo bromine compounds are versatile compounds and are widely used in diverse fields. Organo bromine derivatives are used in the dye sector, as an indicator in analytical chemistry (Bromothymol blue is a popular indicator). One prominent application of synthetic organobromine compounds is the use of polybrominated diphenyl ethers as fire-retardants, and in fact fire-retardant manufacture is currently the major industrial use of the element bromine.Safety of Isopentyltriphenylphosphonium bromide

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary

Palladium-Catalyzed Regioselective Synthesis of 1-Hydroxycarbazoles Under Aerobic Conditions was written by Youn, So Won;Kim, Young Ho;Jo, Yoon Hyung. And the article was included in Advanced Synthesis & Catalysis in 2019.Recommanded Product: 35065-86-2 This article mentions the following:

A palladium-catalyzed aerobic C-H amidation of N-Ts-2-amino-3′-hydroxylbiaryls was developed to afford a diverse range of 1-hydroxycarbazoles with high regioselectivity and efficiency. This protocol benefits from operational simplicity, robustness, and sustainability using ambient air as the sole terminal oxidant. Further elaboration of the products obtained from this process provides facile access to various carbazole alkaloids including carbazolequinones and biscarbazoles. A mechanism involving dual directing group-assisted regioselective C-H activation at the more sterically hindered C2′-position of 2-amino-3′-hydroxylbiaryls is proposed. In the experiment, the researchers used many compounds, for example, 3-Bromophenyl acetate (cas: 35065-86-2Recommanded Product: 35065-86-2).

3-Bromophenyl acetate (cas: 35065-86-2) belongs to organobromine compounds. Many of the organo bromine compounds are relatively nonpolar. Bromine is more electronegative than carbon (2.8 vs 2.5) and hence the carbon in a carbon–bromine bond is electrophilic in nature. In the pharmaceutical industry organo bromine derivatives are used as sedatives, vasodilators, antiseptic agents, and anticancer agents.Recommanded Product: 35065-86-2

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary

Mechanochemical synthesis of magnesium-based carbon nucleophiles in air and their use in organic synthesis was written by Takahashi, Rina;Hu, Anqi;Gao, Pan;Gao, Yunpeng;Pang, Yadong;Seo, Tamae;Jiang, Julong;Maeda, Satoshi;Takaya, Hikaru;Kubota, Koji;Ito, Hajime. And the article was included in Nature Communications in 2021.Recommanded Product: 1-Bromo-4-methoxybutane This article mentions the following:

Since the discovery of Grignard reagents in 1900, the nucleophilic addition of magnesium-based carbon nucleophiles to various electrophiles has become one of the most powerful, versatile, and well-established methods for the formation of carbon-carbon bonds in organic synthesis. Grignard reagents are typically prepared via reactions between organic halides and magnesium metal in a solvent. However, this method usually requires the use of dry organic solvents, long reaction times, strict control of the reaction temperature, and inert-gas-line techniques. Despite the utility of Grignard reagents, these requirements still represent major drawbacks from both an environmental and an economic perspective, and often cause reproducibility problems. Herein, the general mechanochem. synthesis of magnesium-based carbon nucleophiles (Grignard reagents in paste form) in air using a ball milling technique is reported. These nucleophiles can be used directly for one-pot nucleophilic addition reactions with various electrophiles and nickel-catalyzed cross-coupling reactions under solvent-free conditions. In the experiment, the researchers used many compounds, for example, 1-Bromo-4-methoxybutane (cas: 4457-67-4Recommanded Product: 1-Bromo-4-methoxybutane).

1-Bromo-4-methoxybutane (cas: 4457-67-4) belongs to organobromine compounds. Bromine is more electronegative than carbon (2.9 vs 2.5). Consequently, the carbon in a carbon–bromine bond is electrophilic, i.e. alkyl bromides are alkylating agents. One prominent application of synthetic organobromine compounds is the use of polybrominated diphenyl ethers as fire-retardants, and in fact fire-retardant manufacture is currently the major industrial use of the element bromine.Recommanded Product: 1-Bromo-4-methoxybutane

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary

Substituent effects. 6. Charged groups: a simple extension of the Hammett equation was written by Hoefnagel, A. J.;Hoefnagel, M. A.;Wepster, B. M.. And the article was included in Journal of Organic Chemistry in 1978.COA of Formula: C8H7BrO2 This article mentions the following:

Extensive exptl. data show that the Hammett equation fails for charged substituents (poles); variations of σ over >1 unit are common. Addition of the Bjerrum field effect term, δ^B, yields a more general equation which holds satisfactorily for poles (at zero ionic strength) and dipoles; δ^B is a Coulombic term from classical equations, characteristically containing the dielec. constant of the solvent, D_s. Examples are given where only the Bjerrum term counts, among which are acidic ester hydrolysis and 4-CH₂CH₂NMe₃⁺ substitution. Where δ^B â‰?0 the general equation reduces to the form of the Hammett equation. With dipoles this holds almost generally (gas-phase data being 1 of the exceptions); with poles this holds, for instance, for S_N1 reactions and for reactivities at high ionic strengths. The data are also discussed in relation to the meta/para ratio of the inductive effect, the Kirkwood-Westheimer model, the Hine equation, through-resonance effects (σ^L+ and σ^L-), naphthalene derivatives and ortho substitution. The applicability of δ^B in aliphatic systems is illustrated and an extended Taft equation is given. The dichotomous general equation is compatible with a 2-stage model of reactivities. For example, in the first (ionization) stage of the dissociation of XH the X-H distance increases to give a pair of ions or a discrete ion pair X^–H⁺; in the second stage the proton goes to infinity. The 1st stage is structure dependent and equally so for poles and dipoles, and the 2nd stage is structure independent and D_s is applicable. The Kirkwood-Westheimer cavity model can be parametrized so as to conform with the Bjerrum model. This reevaluation of the cavity model is supported by exptl. evidence. In the experiment, the researchers used many compounds, for example, 3-(Bromomethyl)benzoic acid (cas: 6515-58-8COA of Formula: C8H7BrO2).

3-(Bromomethyl)benzoic acid (cas: 6515-58-8) belongs to organobromine compounds. Organo bromine compounds are versatile compounds and are widely used in diverse fields. Organo bromine derivatives are used in the dye sector, as an indicator in analytical chemistry (Bromothymol blue is a popular indicator). When the molecular ion is detected, the bromine and chlorine isotope patterns are very distinct, but caution is to be exercised for certain mixed chlorinated/brominated compounds, which can look similar to homohalogen patterns.COA of Formula: C8H7BrO2

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary

Nonpolar Nucleoside Mimics as Active Substrates for Human Thymidine Kinases was written by Jarchow-Choy, Sarah K.;Sjuvarsson, Elena;Sintim, Herman O.;Eriksson, Staffan;Kool, Eric T.. And the article was included in Journal of the American Chemical Society in 2009.HPLC of Formula: 452-62-0 This article mentions the following:

We describe the use of nonpolar nucleoside analogs of systematically varied size and shape to probe the mechanisms by which the two human thymidine kinases (TK1 and TK2) recognize and phosphorylate their substrate, thymidine. Comparison of polar thymidine with a nonpolar isostere, 2,4-difluorotoluene deoxyriboside, as substrates for the two enzymes establishes that TK1 requires electrostatic complementarity to recognize the thymine base with high efficiency. Conversely, TK2 does not and phosphorylates the hydrophobic shape mimic with efficiency nearly the same as the natural substrate. To test the response to nucleobase size, thymidine-like analogs were systematically varied by replacing the 2,4 substituents on toluene with hydrogen and the halogen series (H, F, Cl, Br, I). Both enzymes showed a distinct preference for substrates having the natural size. To examine the shape preference, we prepared four mono- and difluorotoluene deoxyribosides with varying positions of substitutions. While TK1 did not accept these nonpolar analogs as substrates, TK2 did show varying levels of phosphorylation of the shape-varied set. This latter enzyme preferred toluene nucleoside analogs having steric projections at the 2 and 4 positions, as is found in thymine, and strongly disfavored substitution at the 3-position. Steady-state kinetics measurements showed that the 4-fluoro compound (7) had an apparent V_max/K_m value within 14-fold of the natural substrate, and the 2,4-difluoro compound (1), which is the closest isostere of thymidine, had a value within 2.5-fold. The results establish that nucleoside recognition mechanisms for the two classes of enzymes are very different. On the basis of these data, nonpolar nucleosides are likely to be active in the nucleotide salvage pathway in human cells, suggesting new designs for future bioactive mols. In the experiment, the researchers used many compounds, for example, 3-Bromo-4-fluorotoluene (cas: 452-62-0HPLC of Formula: 452-62-0).

3-Bromo-4-fluorotoluene (cas: 452-62-0) belongs to organobromine compounds. Bromine is more electronegative than carbon (2.9 vs 2.5). Consequently, the carbon in a carbon–bromine bond is electrophilic, i.e. alkyl bromides are alkylating agents. The principal reactions for organobromides include dehydrobromination, Grignard reactions, reductive coupling, and nucleophilic substitution.HPLC of Formula: 452-62-0

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary

Water enables an asymmetric cross reaction of α-keto acids with α-keto esters for the synthesis of quaternary isotetronic acids was written by Chen, Ping;Wang, Kai;Zhang, Boyu;Guo, Wengang;Liu, Yan;Li, Can. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2019.Recommanded Product: 57293-19-3 This article mentions the following:

A water promoted asym. aldol/lactonization/enolization cascade reaction of α-keto acids R¹CH₂C(O)C(O)OH (R¹ = H, Me) and α-keto esters R²C(O)C(O)OC(CH₃)₃ [R² = 4-FC₆H₄(CH₂)₂, CH₂=CH(CH₂)₂, C₆H₅CH₂O(CH₂)₃, etc.] was developed, affording the first general protocol for the construction of chiral quaternary isotetronic acids I with excellent enantioselectivity. Theor. results indicate that intramol. ionized enamine intermediates stabilized by water generate zwitterionic transition states in a lower activation energy and higher face selectivity, resulting in high activity and chemo- and enantioselectivity. In the experiment, the researchers used many compounds, for example, 1-(3-Bromopropyl)-4-methoxybenzene (cas: 57293-19-3Recommanded Product: 57293-19-3).

1-(3-Bromopropyl)-4-methoxybenzene (cas: 57293-19-3) belongs to organobromine compounds. Bromine is more electronegative than carbon (2.9 vs 2.5). Consequently, the carbon in a carbon–bromine bond is electrophilic, i.e. alkyl bromides are alkylating agents. In the pharmaceutical industry organo bromine derivatives are used as sedatives, vasodilators, antiseptic agents, and anticancer agents.Recommanded Product: 57293-19-3

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary

Facile access to 4-aryl-2(5H)-furanones by Suzuki cross coupling: efficient synthesis of rubrolides C and E was written by Boukouvalas, John;Lachance, Nicolas;Ouellet, Michel;Trudeau, Martin. And the article was included in Tetrahedron Letters in 1998.Recommanded Product: 3,5-Dibromo-4-methoxybenzaldehyde This article mentions the following:

The Pd(0)-catalyzed cross coupling between 4-bromo-2(5H)-furanones and arylboronic acids provides the corresponding 4-aryl-2(5H)-furanones in yields of 61-85%. By using this method in conjunction with furanolate chem., the marine antibiotics rubrolides C (I; X = Br) and E (I; X = H) were synthesized in highly efficient fashion (4 steps, 61 and 56% overall yield, resp.) from β-tetronic acid. In the experiment, the researchers used many compounds, for example, 3,5-Dibromo-4-methoxybenzaldehyde (cas: 108940-96-1Recommanded Product: 3,5-Dibromo-4-methoxybenzaldehyde).

3,5-Dibromo-4-methoxybenzaldehyde (cas: 108940-96-1) belongs to organobromine compounds. Bromo compounds are employed in a variety of metal-catalyzed coupling reactions. They are also ideal candidates for the synthesis of Grignard reagents that have wide-applicability in organic synthesis. When the molecular ion is detected, the bromine and chlorine isotope patterns are very distinct, but caution is to be exercised for certain mixed chlorinated/brominated compounds, which can look similar to homohalogen patterns.Recommanded Product: 3,5-Dibromo-4-methoxybenzaldehyde

Referemce:
Bromide – Wikipedia,
bromide – Wiktionary