Tag: M.W=200-250

Tu, Jianzhuo published the artcileIntramolecular (4+3) Cycloadditions of Oxidopyridinium Ions: Towards Daphnicyclidin A, Recommanded Product: Allyldiphenylphosphine oxide, the publication is Chemistry – A European Journal (2022), 28(41), e202200370, database is CAplus and MEDLINE.

N-alkylation of 5-hydroxynicotinic acid esters with electrophiles containing diene functionality produces salts that underwent intramol. (4+3) cycloaddition reactions upon heating in the presence of base. Initial studies used a three-carbon tether to join the pyridinium ion and diene, revealing some aspects of the inherent selectivity of the reaction with such substrates. Much more challenging was the synthesis of related species possessing only a two-carbon tether. Nevertheless, the cycloaddition of such compounds was successful, leading directly to the ABC ring system of the alkaloid daphnicyclidin A.

Chemistry – A European Journal 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 C15H19BO2, Recommanded Product: Allyldiphenylphosphine oxide.

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

Bock, Hans published the artcileRadical ions. 89. One-electron oxidation of diaryl disulfides with aluminum trichloride/dichloromethane, SDS of cas: 77189-99-2, the publication is Phosphorus, Sulfur and Silicon and the Related Elements (1992), 68(1-4), 261-91, database is CAplus.

The single-electron oxidation of 14 alkyl and alkoxy-substituted diaryl disulfides by AlCl₃/H₂CCl₂ has been investigated by ESR/ENDOR spectroscopy. The radical cations observed prove the following skeletal rearrangements: those with ring hydrogens in ortho positions to the disulfide bridge preferentially form thianthrene derivatives The isomeric dinaphthyl disulfides react differently, the 2,2′-isomer yielding the dibenzothianthrene radical cation and the 1,1′-isomer the well-known naphthalene-1,8-disulfide radical cation. For all diaryl disulfides with completely alkyl- or methoxy-blocked ortho positions, oxidative desulfuration is observed As substantiated by addnl. ²D and ³³S isotope marking, bis(3,5-dimethoxyphenyl) disulfide gives both the thianthrene derivative and, by desulfuration, the radical cation of the monosulfide. Accompanying cyclic voltammetric and photoelectron spectroscopic measurements prove that all ESR spectroscopically detected radical cations result from compounds Ar-S-Ar, Ar-SS-Ar and Ar(S)₂Ar with rather low oxidation or ionization potentials and thus suggest that the most easily oxidized paramagnetic species is observed in the rather complex product mixtures

Phosphorus, Sulfur and Silicon and the Related Elements published new progress about 77189-99-2. 77189-99-2 belongs to catalysis-chemistry, auxiliary class Thiophenol,Benzene,Ether, name is 2,4,6-Trimethoxybenzenethiol, and the molecular formula is C9H12O3S, SDS of cas: 77189-99-2.

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

Hunter, B. K. published the artcileChemical shifts for compounds of the Group IV elements silicon and tin, COA of Formula: C12H10F2Si, the publication is Canadian Journal of Chemistry (1968), 46(8), 1399-414, database is CAplus.

Chem. shifts for 29Si in seven series of mols. of the type XnSiY4-n have been measured where Y is an alkyl group and X varies widely in electronegativity. A considerable amount of proton and F chem. shift data has been obtained for the same compounds and in one series (CH3)nSiCl4-n the 13C chem. shifts in the Me groups have been measured. The gross features of the 29Si chem. shifts are understood by considering the series (Alkyl)3SiX with the electronegativity of X widely varied. The hybridization at Si is approx. conserved in these series and the theoretically anticipated linear dependence on electronegativity of X is demonstrated. The ligands X = O, N, and F are exceptional and these 29Si chem. shifts have a high field shift. This addnl. shielding has been associated with (p ¡ú d)¦Ð bonding. The approx. nature of present chem. shift theories is not likely to provide a measure of the order of (p ¡ú d)¦Ð bonding. The 29Si chem. shifts in the series XnSiY4-n are discussed and also indicate a net shielding effect with (p ¡ú d)¦Ð bonding. A comparison is always made with corresponding 13C chem. shifts. A long-range proton-proton coupling in mols. Me3SnX and Me2SnX2, H-C-Si-C-H is observed only when X = O, (N?), F. 119Sn chem. shifts in a series of alkyltin compounds have been measured. The same dependence on the electronegativity of X in the series (alkyl)3SnX is noted, but the variation of X is much more limited. Some shielding due to (p ¡ú d)¦Ð bonding in the series (Butyl)nSnCl4-n is suggested. The Sn chem. shift has been measured as a function of concentration and solvent for simple methyltin bromides and chlorides. In donor solvents, it has been possible to obtain equilibrium constants for complex formation from Sn dilution chem. shifts. The nature of the bonding in complexes suggested previously is consistent with the variations in the coupling constant |JSn-C-H| with concentration The distinction between ionization and complex formation with the solvent for (CH3)2SnCl2 can be made on the basis of the concentration dependence of |JSn-C-H|. The spin-lattice relaxation time T1 for 13C and 29Si in natural abundance in several pure degassed compounds has been measured. These are not in the case of 13C (as has been suggested) of the order several min., but are always <50 sec. and in one case as low as 3-4 sec. Both 29Si and 13C T1 values follow what might be expected on the basis of a dipole-dipole mechanism from the closest protons. The short value of 35 sec. in CS2 is probably a result of spin-rotation interaction in the liquid state. 46 references.

Canadian Journal of Chemistry published new progress about 312-40-3. 312-40-3 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is Difluorodiphenylsilane, and the molecular formula is C12H10F2Si, COA of Formula: C12H10F2Si.

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

Hencsei, Pal published the artcileMolecular structure of phenylhalosilanes. I, Synthetic Route of 312-40-3, the publication is Periodica Polytechnica, Chemical Engineering (1972), 16(2), 101-12, database is CAplus.

Phenylhalosilanes were prepared and their spectra (NMR, uv, ir) determined and related to their mol. structure. Phenylbromosilanes were prepared by reacting MeCOBr with PhnSi(OEt)4-n. The uv spectra showed a bathochromic shift in the order: F, Cl, Br, in compound series of identical types. The ir spectra was used to determine frequencies corresponding to the most important vibrations and from the NMR spectra, the chem. shifts of H in the Me and Ph groups were identified. Compounds of the following type were investigated; PhSiX3, Ph2SiX2, Ph2SiMeX2 (X = F, Br, Cl).

Periodica Polytechnica, Chemical Engineering published new progress about 312-40-3. 312-40-3 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is Difluorodiphenylsilane, and the molecular formula is C12H10F2Si, Synthetic Route of 312-40-3.

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

Veszpremi, Tamas published the artcileInvestigation of the molecular structure of phenylhalosilanes, Safety of Difluorodiphenylsilane, the publication is Kemiai Kozlemenyek (1976), 46(3-4), 418-24, database is CAplus.

Del Re, PPP and IPPP, MO calculations for the UV spectra and dipole moments of 8 PhSiRR1X (R = R1 = X = F, Cl; R = R1 = Ph, X = F, Cl; R = X = F, Cl, R1 = Me, Ph) agreed with exptl. data. The spectra are similar to that of C6H6, with a bathochromic shift. A deformation of the F-Si-F bond angle in PhSiF3 is postulated on the basis of the difference between calculated and exptl. dipole moments.

Kemiai Kozlemenyek published new progress about 312-40-3. 312-40-3 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is Difluorodiphenylsilane, and the molecular formula is C14H10O4, Safety of Difluorodiphenylsilane.

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

Belfield, Kevin D. published the artcileMicrofabrication via two-photon photoinitiated polymerization, Name: 2,6-Diisopropyl-N,N-dimethylaniline, the publication is Polymeric Materials Science and Engineering (1999), 79-80, database is CAplus.

Controlled two-photon induced photopolymn, using both com. monomers (e.g., acrylate, methacrylate) and initiator systems, was demonstrated. Though the efficiency of initiation was not determined quant., qual. the polymerization occurred rapidly, even at higher scanning rates and lower power. This work paves the way for three-dimensional microfabrication of microelectromech. systems and lithog. using readily available materials.

Polymeric Materials Science and Engineering published new progress about 2909-77-5. 2909-77-5 belongs to catalysis-chemistry, auxiliary class Amine,Benzene, name is 2,6-Diisopropyl-N,N-dimethylaniline, and the molecular formula is C14H23N, Name: 2,6-Diisopropyl-N,N-dimethylaniline.

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

Belfield, Kevin D. published the artcileNear-IR Two-Photon Photoinitiated Polymerization Using a Fluorone/Amine Initiating System, Name: 2,6-Diisopropyl-N,N-dimethylaniline, the publication is Journal of the American Chemical Society (2000), 122(6), 1217-1218, database is CAplus.

A controlled 2-photon induced photopolymerization at 775 nm, employing the visible light-absorbing dye H-Nu 470 in the presence of an arylamine and (meth)acrylate monomers is described. Although the efficiency of initiation was not determined quant., qual. it was observed that polymerization occurred rapidly, even at higher scan rates and lower power.

Journal of the American Chemical Society published new progress about 2909-77-5. 2909-77-5 belongs to catalysis-chemistry, auxiliary class Amine,Benzene, name is 2,6-Diisopropyl-N,N-dimethylaniline, and the molecular formula is C14H23N, Name: 2,6-Diisopropyl-N,N-dimethylaniline.

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

Qiu, Zi-bin published the artcileMgBr₂¡¤OEt₂promoted direct Aldol reactions of S-aryl 2-fluoroethanethioate, Related Products of catalysis-chemistry, the publication is Journal of Fluorine Chemistry (2019), 109368, database is CAplus.

MgBr₂¡¤OEt₂-promoted direct aldol reactions of S-aryl 2-fluoroethanethioates with aromatic aldehydes to give the corresponding ¦Á-fluoro-¦Â-hydroxythioesters I [R = Ph, 4-ClC₆H₄, 3,4-Me₂C₆H₃, etc.; Ar = 4-MeC₆H₄, 2,6-Me₂C₆H₃, 2,4,6-iPr₃C₆H₂] was reported. This method had the advantages of use of com. available reagents, mild reaction conditions and operational simplicity.

Journal of Fluorine 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 C15H24S, Related Products of catalysis-chemistry.

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

Huang, Dejian published the artcileCleavage of F-C(sp²) bonds by MHR(CO)(P^tBu₂Me)₂ (M = Os and Ru; R = H, CH₃ or Aryl): Product dependence on M and R, Product Details of C9H9F5Si, the publication is Polyhedron (2006), 25(2), 459-468, database is CAplus.

Both MH(Ph)(CO)L₂ (L = P^tBu₂Me; M = Ru and Os) react with vinyl fluoride to form M-F bonds; however, Ru eliminates benzene, while Os eliminates ethylene. In contrast, Ru(H)₂(CO)L₂ and Os(H)₂(CO)(1-butene)L₂ both react with vinyl fluoride to give ethylene and MHF(CO)L₂. Ethylene production from both dihydrides is attributed to ¦Â-F migration to M from an MCH₂CH₂F transient, while the unique behavior of RuH(Ph)(CO)L₂ (giving the C-F oxidative addition product Ru(¦Ç¹-vinyl)F(CO)L₂) is attributed to the difficulty of achieving Ru^IV, and the ability of the strongly ¦Ð-acidic vinyl fluoride to rapidly trigger reductive elimination of benzene. The products of reaction of RuH(Ar)(CO)L₂ with vinyl fluoride are redirected more towards ethylene formation when Ar carries fluorine substituents. The reaction products of OsH(R)(CO)L₂ with vinyl fluoride revert to R-H elimination when R is Me. Finally, the more ¦Ð-acidic H₂C:CF₂ triggers very rapid CH₄ elimination from OsH(CH₃)(CO)L₂; cleavage of the second C-F bond yields the vinylidene OsF₂(CCH₂)(CO)L₂. All selectivity is rationalized via the fate of the adduct MH(R)(C₂H_4-nF_n)(CO)L₂.

Polyhedron 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, Product Details of C9H9F5Si.

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

Joseph, Roymon published the artcileLower Rim 1,3-Di{bis(2-picolyl)}amide Derivative of Calix[4]arene (L) as Ratiometric Primary Sensor toward Ag⁺ and the Complex of Ag⁺ as Secondary Sensor toward Cys: Experimental, Computational, and Microscopy Studies and INHIBIT Logic Gate Properties of L, Category: catalysis-chemistry, the publication is Journal of Organic Chemistry (2009), 74(21), 8181-8190, database is CAplus and MEDLINE.

A structurally characterized lower rim 1,3-di{bis(2-picolyl)}amide derivative of calix[4]arene (L) exhibits high selectivity toward Ag⁺ by forming a 1:1 complex, among nine other biol. important metal ions, viz., Na⁺, K⁺, Mg²⁺, Ca²⁺, Mn²⁺, Fe²⁺, Co²⁺, Ni²⁺, and Zn²⁺, as studied by fluorescence, absorption, and ¹H NMR spectroscopy. The 1:1 complex formed between L and Ag⁺ was further proven from ESI mass spectrometry and has an association constant, K_a, of 11117 ¡À 190 M^-1 based on fluorescence data. L acts as a primary ratiometric sensor toward Ag⁺ by switch-on fluorescence and exhibits a lowest detectable concentration of 450 ppb. DFT computational studies carried out in mimicking the formation of a 1:1 complex between L and Ag⁺ resulted in a tetrahedral complex wherein the nitrogens of all four pyridyl moieties present on both arms are being coordinated. Whereas these pyridyls are located farther apart in the crystal structure, appropriate dihedral changes are induced in the arms in the presence of silver ion to form a coordination complex. Even the nanostructural features obtained in TEM clearly differentiates L from its Ag⁺ complex. The in situ prepared silver complex of L detects Cys ratiometrically among the naturally occurring amino acids to a lowest concentration of 514 ppb by releasing L from the complex followed by formation of the cysteine complex of Ag⁺. These were demonstrated from emission, absorption, ¹H NMR, and ESI mass spectra. The INH logic gate also was generated by choosing Ag⁺ and Cys as input and by monitoring the output signal at 445 nm that originates from the excimer emission of L in the presence of Ag⁺. Thus L is a potential primary sensor toward Ag⁺ and is a secondary sensor toward Cys.

Journal of Organic Chemistry 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