Tag: M.W=200-250

Sehgal, C. K. published the artcileA novel ring opening of coumarins, Computed Properties of 16909-09-4, the publication is Synthetic Communications (1980), 10(1), 37-42, database is CAplus.

Treatment of coumarins I (R = H or Me; R¹, R² = H, OH or MeO; R³ = H or CH₂CH:CMe₂), furocoumarins II (R⁴ = R⁵ = H or Me; R⁶ = Me, OMe or OH) and dioxolocoumarin III with MeI, EtI or Me₂C:CHCH₂Br with NaH in anhydr. THF gave either a mixture of cis and trans o-alkoxycinnamic acids in which the cis isomer predominated or the cis isomer exclusively. When the coumarin or furocoumarin was substituted in the 4-position, conversion to the cis isomer was almost quant.

Synthetic Communications published new progress about 16909-09-4. 16909-09-4 belongs to catalysis-chemistry, auxiliary class Alkenyl,Carboxylic acid,Benzene,Ether, name is (E)-3-(2,4-Dimethoxyphenyl)acrylic acid, and the molecular formula is C6H16OSi, Computed Properties of 16909-09-4.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Hargreaves, John S. published the artcileThe degradation of dG phosphoramidites in solution, Category: catalysis-chemistry, the publication is Nucleosides, Nucleotides & Nucleic Acids (2015), 34(10), 691-707, database is CAplus and MEDLINE.

The reaction of 2′-deoxynucleoside phosphoramidites with water is an important degradation reaction that limits the lifetimes of reagents used for chem. deoxyoligonucleotide synthesis. The hydrolysis of nucleoside phosphoramidites in solution has therefore been investigated. The degree of degradation depends not only on the presence of water but also on the specific nucleoside, 2′-deoxyguanosine (dG) being especially susceptible. Addnl., the nature of the group protecting the exocyclic amine on the nucleoside base strongly influences the rate of hydrolysis. For dG, the degradation is 2nd-order in phosphoramidite concentration, indicating autocatalysis of the hydrolysis reaction. Comparison of the degradation rates of dG phosphoramidites with different protecting groups as well as with phosphoramidites containing bases that are structurally similar to dG afforded clues to the nature of how dG catalyzes its own destruction and indicated a direct correlation between ease of protecting group removal and the propensity to undergo autocatalytic degradation

Nucleosides, Nucleotides & Nucleic Acids published new progress about 1798-04-5. 1798-04-5 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ether, name is 2-(4-(tert-Butyl)phenoxy)acetic acid, and the molecular formula is C12H16O3, Category: catalysis-chemistry.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Yoshikawa, Hiromichi published the artcileLunularic acid analogs exhibit abscisic acid-like activities in higher plants, Recommanded Product: 4-(Phenoxymethyl)benzoic acid, the publication is Proceedings – Plant Growth Regulation Society of America (2000), 133-138, database is CAplus.

Dihydrostilbene carboxylic acids, phenoxymethylbenzoic acids and benzyloxy-benzoic acids were synthesized as lunularic acid analogs and their biol. activities were estimated by the following bioassays: 1) a cress and lettuce assay 2) an ¦Á-amylase induction test and 3) a Lunularia cruciata callus (A-18 strain) growth test. Some analogs with an electron-withdrawing group at the 3-position of the A ring and a carboxyl group at 2′- or 3′-position of B ring inhibited the germination and the growth of cress (Lepidium sativum). Similar tendency was observed in the growth test of Lunularia cruciata callus. Many compounds were more active than lunularic acid. Moreover, these series of compounds inhibited the ¦Á-amylase induction in barley. The 2,6-dichlorobenzyloxybenzoic acid esters stimulated the growth of lettuce roots but they showed no induction on ¦Á-amylase biosynthesis.

Proceedings – Plant Growth Regulation Society of America published new progress about 31719-76-3. 31719-76-3 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ether, name is 4-(Phenoxymethyl)benzoic acid, and the molecular formula is C14H14, Recommanded Product: 4-(Phenoxymethyl)benzoic acid.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Bhagat, Ujjawal Kumar published the artcileDABCO-mediated aza-Michael addition of 4-aryl-1H-1,2,3-triazoles to cycloalkenones. Regioselective synthesis of disubstituted 1,2,3-triazoles, Computed Properties of 4230-93-7, the publication is Tetrahedron Letters (2017), 58(4), 298-301, database is CAplus.

Aza-Michael addition of 4-aryl-1H-1,2,3-triazoles to 2-cycloalken-1-ones was studied in the presence of DABCO as organic base. The reactions were carried out in acetonitrile at room temperature to provide 2,4-disubstituted 2H-1,2,3-triazoles I [R = H, Me; Ar = C₆H₅, 4-MeC₆H₄, 2-MeO-1-naphthyl, etc.; n = 1] as major adducts and 1,4-disubstituted 1H-1,2,3-triazoles II [n = 0] as minor adducts. Though the reaction times are longer (4-8 days), the two regioisomers were separated by using column chromatog. and the adducts were obtained in very good to excellent combined chem. yields. The electron-rich and electron-poor substituents on aryl moiety of 4-aryl-triazoles could tolerate the reaction conditions to afford the title adducts.

Tetrahedron Letters published new progress about 4230-93-7. 4230-93-7 belongs to catalysis-chemistry, auxiliary class Alkenyl,Nitro Compound,Benzene,Ether, name is 1,2-Dimethoxy-4-(2-nitrovinyl)benzene, and the molecular formula is C10H11NO4, Computed Properties of 4230-93-7.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Xi, Bao-Min published the artcileDrug metabolism-based design, synthesis, and bioactivities of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino)propane hydrochloride (DDPH) analogs as ¦Á₁-adrenoceptors antagonists, Synthetic Route of 4230-93-7, the publication is Bioorganic & Medicinal Chemistry (2011), 19(2), 783-788, database is CAplus and MEDLINE.

1-(2,6-Dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino)propane hydrochloride (DDPH) is a potent ¦Á₁-adrenoceptor antagonist that is currently under Phase II clinic trials. However, the fast metabolism has restricted its further use. In this paper, 11 DDPH analogs were designed according to the probable metabolism pathways of DDPH, and featured the structures of halogen, Me, and cyano groups at the 3-, or 4-position of aromatic ring A to block the hydroxylation, and one hydroxyl group at the 3-, or 4-position of aromatic ring B to extend the duration time. These compounds were synthesized in moderate to good yields from the reductive amination of substituted phenoxyacetones with substituted phenylethylamines, and fully characterized with ¹H NMR, IR, and HRMS. Biol. evaluation indicated that most of the compounds exhibited strong blocking and moderate to good antihypertensive activities. It is clear that the compounds having 4-OH/3-OMe on group B exhibited higher blocking activities and longer duration time than their corresponding analogs having 4-OMe/3-OMe (and also 3-OH/4-OMe). Among them, compound 13 having bromo group at the 4-position of ring A and 4-OH/3-OMe on group B, exhibited the highest blocking activity, whereas compound 17 that had a Me group at the 4-position of ring A and a hydroxyl group at the 4-position of ring B, was more active than potent DDPH in terms of both blocking and antihypertensive activities. In addition, the possible correlations between the blocking and antihypertensive activities are also briefly discussed.

Bioorganic & Medicinal Chemistry published new progress about 4230-93-7. 4230-93-7 belongs to catalysis-chemistry, auxiliary class Alkenyl,Nitro Compound,Benzene,Ether, name is 1,2-Dimethoxy-4-(2-nitrovinyl)benzene, and the molecular formula is C20H23N3O2S, Synthetic Route of 4230-93-7.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Tang, Kaluo published the artcileStudies of trinuclear cadmium cluster complexes. Syntheses and crystal structures of [NMe₄][Cd₃(SC₆H₂Prⁱ₃-2,4,6)₇].C₅H₁₂ and [Cd₃(SC₆H₂Prⁱ₃-2,4,6)₆(HSC₆H₂Prⁱ₃-2,4,6)].CH₃OH.7H₂O, Application of 2,4,6-Triisopropylbenzenethiol, the publication is Journal of Coordination Chemistry (1994), 31(4), 305-20, database is CAplus.

By the reaction of a sterically hindered arenethiol, 2,4,6-(Me₂CH)₃C₆H₂SH (HL), with Cd(NO₃)₂.4H₂O under different conditions, the colorless salt of trinuclear cadmium cluster anion complex [NMe₄][Cd₃(L)₇].C₅H₁₂ (I) and the uncharged trinuclear cadmium complex [Cd₃(L)₆(HL)].MeOH.7H₂O (II) were synthesized and structurally characterized. Crystals of I are monoclinic, space group P2₁/n with a 19.629(6), b 25.608(9), c 25.450(9) ?, ¦Â 107.54(3)¡ã, Z = 4, R = 0.076 for 3839 observed reflections. Crystals of II are triclinic, space group, P1? with a 19.792(10), b 20.508(12), c 33.97(2) ?, ¦Á 85.81(5), ¦Â 86.77(5), ¦Ã 85.12(4)¡ã, Z = 4, R = 0.0921 for 8327 observed reflections. The core of the cluster anion of I is formed by a defect cubane unit with 3 cadmium and 4 sulfur atoms at its vertexes. Each cadmium atom exhibits tetrahedral coordination with 1 terminal sulfur, 2 doubly bridging sulfur and 1 triply bridging sulfur atoms. In complex II, 3 cadmium atoms are coordinated by 6 thiolate (RS^–) and 1 thiol (RSH) ligands. Two of 3 cadmium atoms have tetrahedral coordination and 1 is trigonal planar.

Journal of Coordination Chemistry published new progress about 22693-41-0. 22693-41-0 belongs to catalysis-chemistry, auxiliary class Other Functionalization Reagent, name is 2,4,6-Triisopropylbenzenethiol, and the molecular formula is C28H29NO4, Application of 2,4,6-Triisopropylbenzenethiol.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Elsby, Matthew R. published the artcileNickel-Catalyzed C-H Silylation of Arenes with Vinylsilanes: Rapid and Reversible ¦Â-Si Elimination, Recommanded Product: Trimethyl(perfluorophenyl)silane, the publication is Journal of the American Chemical Society (2017), 139(27), 9401-9407, database is CAplus and MEDLINE.

The reaction of C₆F₅H and H₂C:CHSiMe₃ with catalytic [ⁱPr₂Im]Ni(¦Ç²-H₂C:CHSiMe₃)₂ (1b) exclusively forms the C-H silylation product C₆F₅SiMe₃ with ethylene as a byproduct ([ⁱPr₂Im] = 1,3-di(isopropyl)imidazole-2-ylidene). Catalytic C-H bond silylation is facile with partially fluorinated aromatic substrates containing two ortho F substituents adjacent to the C-H bond and 1,2,3,4-tetrafluorobenzene. Less fluorinated substrates react slower. Under the same reaction conditions, catalytic [IPr]Ni(¦Ç²-H₂C:CHSiMe₃)₂ (1a) ([IPr] = 1,3-bis[2,6-diisopropylphenyl]-1,3-dihydro-2H-imidazol-2-ylidene) provided only the alkene hydroarylation product C₆F₅CH₂CH₂SiMe₃. Mechanistic studies reveal that the C-H activation and ¦Â-Si elimination steps are reversible under catalytic conditions with both catalysts 1a and 1b. With catalytic 1a, reversible ethylene loss after ¦Â-Si elimination was also observed despite its inability to catalyze C-H silylation; the reductive elimination step to form the silylation product is much slower than reductive elimination to form the alkene hydroarylation product. Reversible ethylene loss was not observed with 1b, which suggests that the rate-limiting step in the reaction is neither C-H activation nor ¦Â-Si elimination but either ethylene loss or reductive elimination of cis-disposed aryl and SiMe₃ moieties.

Journal of the American Chemical Society published new progress about 1206-46-8. 1206-46-8 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is Trimethyl(perfluorophenyl)silane, and the molecular formula is C9H9F5Si, Recommanded Product: Trimethyl(perfluorophenyl)silane.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Exner, O. published the artcileQuantitative evaluation of the inductive effect, Application In Synthesis of 31719-76-3, the publication is Collection of Czechoslovak Chemical Communications (1962), 02296-306, database is CAplus.

The relative pK’ values obtained by measuring the dissociation constants of p-toluic acids, substituted in the Me group, in 50% (by volume) aqueous EtOH (I) and 80% (by weight) Methyl Cellosolve (II), are considered as a measure of the inductive effect of the substituents. From the results it follows that the transmission of the inductive effect takes place predominantly along the ¦Ä-bonds (and not space). Refluxing p-ClCH₂C₆H₄CN (IIa) with azeotropic HBr 12 hrs. gave 62% p-BrCH₂C₆H₄CO₂H, m. 229¡ã (EtOH), also formed in 90% yield by refluxing p-HOCH₂C₆H₄CO₂Me with the same reagent. p-ClCH₂C₆H₄CO₂H (III) (1.71 g.) and 4 g. NaI refluxed 1 hr. in 30 ml. Me₂CO, the solution evaporated to dryness in vacuo, the inorganic salts washed out with H₂O, and the product washed with a dilute solution of Na₂S₂O₃ gave 66% p-ICH₂C₆H₄CO₂H, m. 235¡ã (EtOH). Refluxing 1.71 g. III with 0.46 g. Na in 30 ml. absolute MeOH 3 hrs., evaporating the MeOH in vacuo, and precipitating by HCl gave 70% p-MeOCH₂C₆H₄CO₂H, m. 108¡ã (CHCl₃, petr. ether). Similar procedure with 1.71 g. III, 0.94 g. PhOH, and 0.46 g. Na in 30 ml. MeOH gave 55% p-PhOCH₂C₆H₄CO₂H, m. 216¡ã (dilute EtOH). Adding 0.8 ml. AcCl to 1.52 g. p-HOCH₂C₆H₄C0₂H in 5 ml. C₅H₅N, cooling the mixture after 15 min., and pouring into dilute HCl gave 88% p-AcOCH₂C₆H₄CO₂H, m. 128¡ã (C₆H₆). p-PhCH₂C₆H₄CO₂H, prepared from p-BrCH₂C₆H₄CN (IV) and C₆H₆ in a 68% overall yield, m. 160¡ã (dilute EtOH). Partial hydrolysis of p-NCCH₂C₆H₄CO₂H afforded 51% p-H₂NCOCH₂C₆H₄CO₂H, m. 274¡ã (EtOH). Refluxing 1.71 g. III with 1 g. NaSCN in 30 ml. EtOH 3 hrs., evaporating the solution to dryness in vacuo, eluting the salts with H₂O, and repptg. the crude product from 10% aqueous KOH gave 80% p-NCSCH₂C₆H₄CO₂H, m. 172¡ã (EtOAc). Refluxing 1.61 g. p-BrCH₂C₆H₄CO₂H with 2.2 g. PhSO₂Na in 25 ml. EtOH 8 hrs. yielded 95% p-PhSO₂CH₂C₆H₄CO₂H, m. 306¡ã (decomposition) (EtOH). Adding 4.9 g. IV to a mixture of 8.2 g. Me₂NH.HCl and 3.5 g. NaOH in 10 ml. H₂O and 25 ml. EtOH, allowing the mixture to stand overnight, refluxing 30 min., evaporating the EtOH in vacuo, dissolving the residue in H₂O, extracting the solution with three 15-ml. portions CHCl₃, evaporating the extract, refluxing the residue 3 hrs. with a solution of 3 g. NaOH in 20 ml. 50% EtOH, acidifying the reaction mixture with HCl, evaporating to dryness in vacuo, and extracting the residue with boiling EtOH gave 56% p-Me₂NCH₂C₆H₄CO₂H.HCl, m. 256¡ã (EtOH). Allowing a mixture of 3.03 g. IIa and 2.8 g. (CH₂)₆N₄ in 50 ml. CHCl₃ to stand 2 days at room temperature, concentrating the solution to 10 ml. in vacuo, filtering off 4.11 g. of a salt, dissolving it in 20 ml. 1:2 HCl and EtOH, distg, to dryness in vacuo, and extracting the residue with Me₂CO gave 52% p-H₂NCH₂C₆H₄CN.HCl, m. 269¡ã (EtOH). Hydrolysis by refluxing 16 hrs. with concentrated HCl, followed by acetylation with AcCl in pyridine, gave 43% p-Ac-NHCH₂C₆H₄CO₂H, m. 201¡ã (EtOH). The measurements of the apparent dissociation constants were carried out using an electronic pH meter with a vibrating condenser and a cell having a glass electrode and calomel reference electrode. The substances in concentrations of the order of 10^-3M were titrated with aqueous Me₄OH. The apparent dissociation constants (pK’) in solvents I and II for the appropriate substituents in ¦Á-position of p-MeC₆H₄CO₂H are for: H, 5.78, 6.82; Cl, 5.36, 6.45; Br, 5.36, 6.36; iodine, 5.41, 6.41; Ph, 5.70, 6.73; CN, 5.28, 6.32; CONH₂, 5.44, 6.69; OH, 5.56, 6.70; OMe, 5.50, 6.58; OPh, 5.43, 6.56; OAc, 5.46, 6.50; NHAc, 5.61, 6.68; NMe₂.HCl, 4.67, –; SCN, 5.33, 6.46; and PhSO₂, –, 6.36.

Collection of Czechoslovak Chemical Communications published new progress about 31719-76-3. 31719-76-3 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ether, name is 4-(Phenoxymethyl)benzoic acid, and the molecular formula is C14H12O3, Application In Synthesis of 31719-76-3.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Basinger, Mark A. published the artcileRelative efficacy of chelating agents as antidotes for acute nickel(II) acetate intoxication, HPLC of Formula: 38260-01-4, the publication is Research Communications in Chemical Pathology and Pharmacology (1980), 30(1), 133-41, database is CAplus and MEDLINE.

The relative efficacy of 14 chelating agents in alleviating acute Ni(OAc)₂ [373-02-4] (i.p.) intoxication was determined The LD₅₀ for i.p. Ni(OAc)₂ in mice was 45.7 mg/kg with a 95% confidence limit of 39.2-53.3 mg/kg. With 62 mg Ni(OAc)₂/kg (i.p.) (i.e. ¡ÝLD₉₀), the most effective antidotes were D-penicillamine [52-67-5] and Na₂CaEDTA [62-33-9]. The acetylation of the NH₂ group in penicillamine to give N-acetyl-D,L-penicillamine [59-53-0] effectively destroys the antidotal action, as would be expected if coordination to the N were essential to the process.

Research Communications in Chemical Pathology and Pharmacology published new progress about 38260-01-4. 38260-01-4 belongs to catalysis-chemistry, auxiliary class Chelating Agents, name is N1,N1′-(Ethane-1,2-diyl)bis(ethane-1,2-diamine) dihydrochloride, and the molecular formula is C6H20Cl2N4, HPLC of Formula: 38260-01-4.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Schirmer, Marie-Luis published the artcileOrganocatalyzed Reduction of Tertiary Phosphine Oxides, Category: catalysis-chemistry, the publication is Advanced Synthesis & Catalysis (2016), 358(1), 26-29, database is CAplus.

A novel selective catalytic reduction method of tertiary phosphine oxides to the corresponding phosphines has been developed. Notably, the reaction proceeds smoothly with low catalyst loadings of 1-5 mol% even at low temperature (70¡ã). Under the optimized conditions various phosphine oxides could be selectively reduced and the desired phosphines were usually obtained in excellent yields above 90%. Furthermore, authors have developed a one-pot reaction sequence for the preparation of valuable phosphine¡¤borane adducts. Simple addition of BH₃¡¤THF subsequent to the reduction step gave the desired adducts in yields up to 99%.

Advanced Synthesis & Catalysis published new progress about 4141-48-4. 4141-48-4 belongs to catalysis-chemistry, auxiliary class Aryl phosphine ligand,Mono-phosphine Ligands, name is Allyldiphenylphosphine oxide, and the molecular formula is C15H15OP, Category: catalysis-chemistry.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia