An efficient synthesis of mono-, di-, tetra-, and octa-valent difluorinated zanamivir analogs as potent inhibitors of influenza virus is reported. The mono difluorinated zanamivir with an azide linker attached at the C-7 position was synthesized in good yield from sialic acid using Selectfluor® and (diethylaminosulfur trifluoride) DAST as the fluorination reagent. This key intermediate was attached...
A simple and efficient method has been developed for the synthesis of quinoline derivatives from N-alkyl anilines and alkynes or alkenes by iron-catalyzed oxidative coupling reactions. A variety of substituted quinolines are prepared in good to excellent yields.
We have synthesized a ferrocene-based 1,3-alternate thiacalixarene ditopic receptor 3 that contains four identical polyether arms terminated with the ferrocene amide moieties. Our studies have revealed that this redox-active receptor can be used as an electrochemical sensor to recognize both europium (Eu 3+ ) and dihydrogen phosphate (H2PO4-) ions with a high selectivity.
9-Amino(9-deoxy)epiquinine and 9-amino(9-deoxy)epicinchonine were applied in asymmetric transfer hydrogenation of aromatic ketones in both iridium and rhodium catalytic systems using i-propanol as the hydrogen source. Good to excellent conversions and enantioselectivities were observed with a variety of aromatic ketones. Moreover, the Ir complex and Rh complex of 9-amino(9-deoxy)cinchonine were recovered...
A green, simple and effective polymeric organocatalytic system, polymer-supported triphenylphosphine (PS-TPP), for the stereoselective isomerization of α,β-ynones to (E,E)-α,β-γ,δ-dienones is reported here. The catalyst, PS-TPP could be recovered by simple filtration and reused several times with high activity.
The backbone of diene precursor in the proposed biogenesis of methyl isosartortuoate through a Diels-Alder reaction has been constructed via dehydration to establish the conjugated system; and double cyclization by using Horner-Wittig-Emmons reaction and the chiral epoxy ring opening.
The crystal structures of triptycene and pentiptycene secondary diamides 1 and 2 grown from methanol solutions are reported. In addition, the crystal structure of 1 from a toluene-methanol mixed solution was also determined. The molecular structures of 1 in both crystals are folded, and an anomalous hydrogen-bonding chain motif is generated. On the other hand, the pentiptycene diamide 2 adopts an...
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