The stereoselective direct transformation of N-(propargylic)hydroxylamines into cis-2-acylaziridines was achieved by the combined use of AgBF4 and CuCl. Copper salts were found to promote the transformation of the intermediary 4-isoxazolines into 2-acylaziridines and both 3-aryl- and 3-alkyl-substituted 2-acylaziridines could be prepared by using this method. Furthermore, subsequent 1,3-dipolar...

Regioselective additions of pyrroles to a variety of optically active nitrones under smooth acidic conditions lead to chiral pyrrolic N-hydroxylamines in good to excellent yields. Depending on the position of the chirality on the nitrone partner, the addition products have been isolated with high diastereoselectivity levels. Reaction of glyoxylate based chiral nitrones either at the C-2 or at t...

1,3-Dipolar cycloaddition of dihydropyran derived nitrones synthesized from 2,3 dihydro 4H-pyran and various hydroxylamines, with electron deficient alkynes are found to have significant rate acceleration and improved yields of isoxazolines in 1-Butyl-3-methylimidazolium based ionic liquids while with enals exclusively endo isoxazolidines are obtained with high selectivity. Synthetic potentiali...

Vinylidene complexes [Ru(η(5)-C5H5){[double bond, length as m-dash]C[double bond, length as m-dash]C(H)R}(PPh3)L]BPh4 (, ) [L = P(OMe)3, P(OEt)3; R = Ph, p-tolyl, Bu(t), H] react with hydrazine R1NHNH2 (R1 = H, Me, Ph) to afford nitrile derivatives [Ru(η(5)-C5H5)(N[triple bond, length as m-dash]CCH2R)(PPh3)L]BPh4 (, ) and amine R1NH2. Hydroxylamine NH2OH also reacts with vinylidenes , to yield ...

The interconversion of ortho-hydrogen (oH(2)) and para-hydrogen (pH(2)), the two nuclear spin isomers of dihydrogen, requires a paramagnetic spin catalyst such as a nitroxide. We report the design and demonstration of spin catalysis of the interconversion of oH(2) and pH(2) incarcerated in an endofullerene based on a reversible nitroxide/hydroxylamine system. The system is an example of a rever...

α,α-Dicyanoolefins react with hydroxylamine to afford 2,3-dihydroisoxazoles (2,3-dihydroisoxazoles can be easily isolated by filtration) in excellent yields under mild and environmentally benign conditions. A one-pot reaction in tandem with an unexpected ring-opening of 2,3-dihydroisoxazoles has been developed as well.

A hydroxamic acid (HX) derivative of pectin was prepared, and its potential application to simple colorimetric determination of polysaccharides was investigated. The coupling reaction between pectin and hydroxylamine (HA) progresses in the presence of 1-cyclohexyl-3-(2-morpholinoethyl) carbodiimide metho-p-toluenesulfonate (CMEC). The calibration curve for pectin showed good agreement and the l...