P-Hydroxytetraorganophosphorane, the long-postulated intermediate in phosphonium salt and ylide hydrolysis, has been observed and characterised by low temperature NMR, finally definitively establishing its involvement in these reactions. The results require modification of the previously accepted mechanism for ylide hydrolysis: P-hydroxytetraorganophosphorane is generated directly by 4-centre r...

I have developed a procedure to monitor, by gas chromatography with electron-capture detection, the concentration of vaiproic acid in serum. The valprolc acid Is derivatized into Its phenacyl ester. The assay Is very sensitive, measuring as little as 100 pg of valproic acid easily and accurately. Solvent extraction and concentration of the drug are not necessary; Instead, one only has to precip...

A phosphine-catalyzed dearomatizing [3+2] annulation of isoquinolinium methylides with allenoates or allenones yields highly functionalized pyrroloisoquinolines with high regioselectivity and in viable yields.

Photolysis of derivatives of dimethylmalonate thiophene-S,C-ylide provides dicarbomethoxycarbene, which can react with thiophene to form dimethyl (2-thienyl)malonate. By generation of dicarbomethoxycarbene from the dibenzothiophene-based ylide in neat thiophene, it is shown that the thienylmalonate is not a product of rearrangement of the thiophene ylide, in contrast to thermolysis results. For...

In this paper, we describe studies on the cyclopropanation of Michael acceptors with chiral sulfur ylides. It had previously been found that semi-stabilized sulfonium ylides (e.g., Ph-stabilized) reacted with cyclic and acyclic enones and substituted acrylates with high ee and that stabilized sulfonium ylides (e.g., ester-stabilized) reacted with cyclic enones again with high ee. The current st...

We have developed a highly efficient procedure for carrying out the catalytic enantioselective (3+2) cycloaddition between enals and stable azomethine ylides such as isoquinolinium and phthalizinium methylides. Under the optimized reaction conditions highly substituted chiral pyrroloisoquinolines and pyrrolophthalazines have been obtained in high yields and excellent diastereo- and enantioselec...

A series of functionalized spiro[indoline-3,2'-oxiran]-2-ones was efficiently synthesized by Darzens reaction of phenacyl bromides with isatins both with N-alkyl groups and without N-substituent in the presence of potassium carbonate as a base catalyst. When two equivalents phenacyl bromides were used in the reaction, the N-substitution reaction of isatin also finished with the formation of spi...

Thanks to the +PCy3 substituents which are unlikely undergo intramolecular C–H activation, Pd(II) complex [(C,C,C)PdCl](OTf) having a neutral LX2-type NHC, diphosphonium bis(ylide) pincer ligand was selectively prepared by double deprotonation of [(NHC)PdCl2(Py)] precursor with tBuOK. The influence on overall electronic properties this scaffold evaluated IR spectroscopy data corresponding Pd–CO...