نتایج جستجو برای: phosphine
تعداد نتایج: 3411 فیلتر نتایج به سال:
Nitrosothiols (RSNOs) have been proposed as important intermediates in nitric oxide (NO(•)) metabolism, storage, and transport as well as mediators in numerous NO-signaling pathways. RSNO levels are finely regulated, and dysregulation is associated with the etiology of several pathologies. Current methods for RSNO quantification depend on indirect assays that limit their overall specificity and...
Primary and secondary phosphine complexes are convenient precursors of terminal phosphido-metal compounds by deprotonation. Recent work has shown that the chiral tertiary phosphido-metal group Fe —PMePh can be generated stereospecifically by deprotonation of a resolved secondary phosphine complex at —90 °C, and, furthermore, that it can be alkylated with retention of configuration and com plet...
Most studies on phosphorus cycle in the natural environment focused on phosphates, with limited data available for the reduced phosphine (PH3). In this paper, matrix-bound phosphine (MBP), gaseous phosphine fluxes and phosphorus fractions in the soils were investigated from a penguin colony, a seal colony and the adjacent animal-lacking tundra and background sites. The MBP levels (mean 200.3 ng...
The diarylamido/bis(phosphine) PNP pincer ligand (2-(i)Pr(2)P-4-MeC(6)H(3))(2)N has been evaluated as a scaffold for supporting a BF(2) fragment. Compound (PNP)BF(2) (6) was prepared by simple metathesis of (PNP)Li (5) with Me(2)SBF(3). NMR spectra of 6 in solution are of apparent C(2) symmetry, suggestive of a symmetric environment about boron. However, a combination of X-ray structural studie...
The thermal decomposition of trans-chloroethylbis(triethylphosphine)platinum(II) (L2PtEtCl, 1) in cyclohexane solution at 158 oC yields trons-chlorohydridobis(triethylphosphine)platinum(II) (3) and ethylene. The most probable rate-limiting step for this reaction is dissociation of ethylene from a five-coordinate l8-electron plat inum(Il) intermediate, L2PtHCl(CzH) Q). Three pathways might be in...
Inheritance of resistance to phosphine fumigant was investigated in three field-collected strains of rusty grain beetle, Cryptolestes ferrugineus, Susceptible (S-strain), Weakly Resistant (Weak-R) and Strongly Resistant (Strong-R). The strains were purified for susceptibility, weak resistance and strong resistance to phosphine, respectively, to ensure homozygosity of resistance genotype. Crosse...
The combination of iron salts and N-heterocyclic carbene (NHC) ligands is a highly effective combination in catalysis, with observed catalytic activities being highly dependent on the nature of the NHC ligand. Detailed spectroscopic and electronic structure studies have been performed on both three- and four-coordinate iron(II)-NHC complexes using a combined magnetic circular dichroism (MCD) an...
A novel phosphine-catalyzed intermolecular [3 + 2] cycloaddition of ynones and N-substituted isatins was developed. In this reaction, substituted ynones, serving as a C(3) synthon, were successfully applied in intermolecular annulation reactions. A number of functionalized spirooxazolines were obtained in high yields and stereoselectivity.
A facile synthesis of spirofuran oxindoles via phosphine-mediated reaction of 3-alkyl allenoate with isatins is presented.
A phosphine-catalyzed dearomatizing [3+2] annulation of isoquinolinium methylides with allenoates or allenones yields highly functionalized pyrroloisoquinolines with high regioselectivity and in viable yields.
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