Synthesis and Reactions of Some New Pyrrolylfuro[2,3‐d]Pyrimidines and Pyrrolopyrazinofuropyrimidines

5‐Amino‐4‐methyl‐2‐phenyl‐6‐substitutedfuro[2,3‐d]pyrimidines ( 2a‐c ) were reacted with 2,5‐dimethoxytetrahydrfuran to afford the pyrrolyl derivatives 3a‐c . Compound 3a was chosen as intermediate for the synthesis of poly fused heterocycles incorporated furopyrimidines moiety 4–11 . Some of the synthesized compounds were screened for their antibacterial and antifungal activities.     

Boron-Nitrogen Compounds 83 [1]. Experimental and Theoretical Studies on Monomeric Iminoboranes

Nuclear magnetic resonance and vibrational spectroscopic data support the existence of liner C?N? B skeleton in monomeric iminoboranes of the type R₂C?N? BR. This allene-like arrangement of the central moiety of the compounds does not seem to enhance the N? B bond strength by interaction of this bond with the vicinal C?N bond. Rather, in the case of R′ being a hydrocarbon group, the nature of the N? B bond is similar to that found in (monoamino) diorganyl-boranes, R₂N? Br. Similarly, (CF₃)₂C?N? B[N(CH₃)₂]₂ may ve viewed as a trisaminoborane. However, the rigid C?N? BN₂ unit makes this compound colored and the electronic structure of the species was studied; theoretical and experimental data are in good agreement.     

On the Discrete Hardy Inequality

Necessary and sufficient conditions for the boundedness of thediscrete Hardy operator of the form , from to when 0 < q < 1 <p , is given.     

Reaction of singlet oxygen with trans-4-propenylanisole. Formation Of

We report the effects of added acid in the reaction of singlet oxygen with trans-4-propenylanisole (1). We provide evidence that solvent acidity modifies the behavior of the transient intermediates. Relative to reactions in aprotic solvent, enhanced dioxetane concentrations are observed in MeOH and in nonprotic solvents with acid. We suggest a new mechanism that invokes a proton transfer from MeOH and benzoic acid to perepoxide (2) and zwitterion (3) intermediates.     

Electroreduction of oxygen on Pd catalysts supported on Ti-modified carbon

Carbon supports modified with well dispersed anatase TiO₂ (C–Ti-X; X (0.25, 0.5, 0.75, and 1.0) represents mass ratio of Ti precursor to carbon) were synthesized with various Ti loadings and used to support Pd catalysts for oxygen reduction. The anatase nanoparticles increased in size with increasing Ti loading. Pd dispersion improved with increasing Ti loading up to the C–Ti-0.75, which resulted in the best catalytic activity. Although the Pd dispersion was lowest on the C–Ti-1.0, it showed better catalytic performance than the catalysts supported on C–Ti-0.25 and C–Ti-0.5. At 0.8 V (vs. RHE), the best catalytic activity achieved was respectively 2.7 and 2.7 times the mass and specific activities of Pd supported on un-modified carbon. The interaction between Pd and highly dispersed TiO₂ is believed to improve the catalytic activity of Pd supported on TiO₂-modified carbons.