Highly diastereoselective nucleophilic addition to myrtenal. Straightforward synthesis of an enantiopure scorpionate ligand

The work described here represents the first example in which an efficient and highly diastereoselective nucleophilic 1,2-addition of an organolithium reagent has been performed on a carbonylic prostereogenic center to give an enantiopure scorpionate ligand in only one step.     

Highly efficient retro-cycloaddition reaction of isoxazolino[4,5:1,2][60]- and -[70]fullerenes

Isoxazolino[4,5:1,2][60]- and -[70]fullerenes undergo an efficient retro-cycloaddition reaction to pristine fullerene by thermal treatment in the presence of an excess of a dienophile and Cu(II) catalysis, which can be selectively used in the presence of malonate or pyrrolidine cycloadducts. Trapping experiments using N-phenylmaleimide as dipolarophile have shown that the reaction mechanism occurs by thermal removal of the nitrile oxide 1,3-dipole, in a process which is favored by the presence of Cu(II) as the catalyst. The ESI-MS study supports the observed retro-cycloaddition process for both C60 and C70 derivatives. In contrast to previous electrochemical retro-cycloaddition processes observed in fulleropyrrolidines, isoxazolinofullerenes were stable under oxidative conditions.     

Synthesis and structural studies of new N‐(p‐toluenesulfonyl)amino acid o‐phenolamides

N‐(p‐Toluenesulfonyl)glycine o‐phenolamide ( 3a ) and the analogous derivatives of d,l‐alanine ( 3b ), L ‐valine ( 3c ), L ‐leucine ( 3d ), and L ‐phenylalanine ( 3e ) were synthesized in yields >80% by condensation of N‐(p‐toluenesulfonyl)amino acyl chlorides with o‐aminophenol. The structure and conformation of these amides were established by NMR spectroscopy and X‐ray crystallography. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:247–253, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10135     

Efficient synthesis of B-alkylated oxazaborolidines derived from ephedrine and norephedrine

[reaction: see text] Representative B-butyl- and B-methyl-1,3,2-oxazaborolidines derived from ephedrine and norephedrine were prepared in good yield and excellent purity by one-pot treatment of B-H oxazaborolidines with the corresponding organolithium reagent and subsequent hydrolysis of the cyclic borohydride intermediate with anhydrous ammonium chloride.     

Squeezed states and uncertainty relations since 1991

A brief review of the history of ten workshops/conferences on “Squeezed States and Uncertainty Relations” and main achievements in the related fields of quantum physics for the period from 1991 to 2007 are presented.     

Highly selective and sensitive chromo-fluorogenic detection of the Tetryl explosive using functional silica nanoparticles

Silica nanoparticles containing polyamines and thiol groups have been used as probes for the selective detection of Tetryl.     

Naproxen: Hydroxypropyl-β-Cyclodextrin:Polyvinylpyrrolidone Ternary Complex Formation

The aim of the present study was to investigate the effect of the presence of thewater-soluble polymer polyvinylpyrrolidone (PVP) MW = 24000 g/mol, on thecomplexation of the phototoxic anti-inflammatory drug naproxen, in its sodiumsalt form, with hydroxypropil-β-cyclodextrin (HP-β-CD). The datashown that the polymer interacts with the free naproxen and with thenaproxen:HP-β-CD inclusion complex. The presence of different proportions of PVP, in the 0–1%(w/w) rangesystematically increased the K_app of the naproxen:HP-β-CD inclusioncomplex formation. The cause of this increase is that the polymer interactswith the HP-β-CD with a binding constant of K₂ = 29000 ± 53 M^-1; and with the naproxen:HP-β-CD inclusion complex, to givea ternary complex naproxen:HP-β-CD:PVP. The binding constant of thisprocess was K₃ = 5350 ± 1 M^-1. NMR data revealed that in the ternary system, PVP is outside of the cyclodextrin, and therefore must be wholly or partially recovering the naproxen:HP-β-CD inclusion complex.