The synthesis of recyclable ionic liquid-supported imidazolidinone catalyst I and its application in 1,3-dipolar cycloaddition of nitrone with α,β-unsaturated aldehyde with high performance were described. Most importantly, the catalyst I can be recovered and recycled for up to five runs without observing significant decrease in catalytic activity.

The resolution of chiral nitrones via derivatization of hydroxylamines was applied to MiPNO, a new, stable, easily prepared chiral cyclic nitrone. The application of MiPNO in totally regio- and diastereo-selective 1,3-dipolar cycloaddition reactions provides an expeditious enantioselective access to unusual gamma-hydroxy alpha-amino acids.

The dipolar cycloaddition reactivity of N-(1-naphthy1)-1,4- benzoquinoneimine N-oxide and N-phenyl-1,4- naphthoquinoneimine Noxide are investigated, The latter gives the expected adducts with common dipolarophiles such as acrylonitryle, methyl methacrylate, dimethylacetylene dicarboxylate and N-phenylmaleimide. The reactivity of the former nitrone is found to be minimal. It undergoes, how...

Truncated phosphonated C-1'-branched N,O-nucleosides have been synthesized in good yields by 1,3-dipolar cycloaddition methodology, starting from N-methyl-C-(diethoxyphosphoryl)nitrone 7. Preliminary biological assays show that β-anomers are able to inhibit HIV in vitro infection at concentrations in the micromolar range. Higher SI values with respect to AZT indicated that the compounds were en...

BACKGROUND 1,3-Dipolar [3 + 2]-cycloaddition of nitrones to the carbon-carbon double bonds of methylenecyclopropanes yields a mixture of regioisomeric 4- and 5-isoxazolidines. The mechanisms of the reactions of N,C,C-trisubstituted nitrones with ring acceptor substituted dimethyl methylenecyclopropanes-1,2-dicarboxylate and aryl methylidene cyclopropanes-1,1-dicarboxylate have been investigated...

Nitrones undergo dynamic exchange in chloroform at room temperature through two mechanisms-hydrolysis and recombination or hydroxylamine addition/elimination; this dynamic exchange is harnessed to select a nitrone-based bis(amidopyridine) receptor for diacids from a group of four nitrones through its binding to a glutaric acid-based target.

Intramolecular transannular dipolar cycloaddition was investigated as a key step in a synthetic approach to the core of the sarain alkaloids; although the use of an azomethine ylide was unsuccessful with the chosen aldehyde substrate, cycloaddition with a nitrone did give the alternative regioisomeric bridged cycloadduct.