The reaction o f 1-hydroxyxanthenone (1) and hydroxyquinoline (10, 13) Mannich bases with the reactive phosphacumulated ylides (2), represents a new way for the synthesis o f the pyranones and pyranthiones (5, 11, 14). On the other hand, the stabilized phosphorus ylides (6) affect the transylidation o f the Mannich base (1) to the corresponding phosphoranylidenes (9). The structure o f the resu...

We describe the nearly quantitative preparation of phosphorus ylides and the Wittig reaction occurring in the solid sate during high-energy mechanochemical processing. Initial insights into the details of the discovered chemical transformations indicate that high-energy mechanical processing supports the interaction of reacting centers by breaking crystallinity of the reactants and by providing...

Preparation of new types of trisubstituted oxazoles is realized via chemoselective O-acylations and intramolecular Wittig reactions with ester functionalities using in situ formed phosphorus ylides as key intermediates. A plausible reaction mechanism for this undiscovered chemistry is also proposed based on the existence of expected and rearranged isomeric oxazoles.

Phosphine-catalyzed [4+1] annulation of electron-deficient 1,3-dienes or 1,3-azadienes with maleimides has been successfully developed under very mild conditions, providing a convenient and highly efficient method for constructing 2-azaspiro[4.4]nonenes and 1,7-diazaspiro[4.4]nonenes. This reaction represents the first example of [4+1] cyclization between electron-deficient 4π-conjugated system...

A general preparation of new types of benzofurans, benzothiophenes and indoles is realized via chemoselective intramolecular Wittig reactions with the corresponding ester, thioester and amide functionalities using in situ formed phosphorus ylides as key intermediates. The reaction conditions are very mild, and numerous Michael acceptors and commercially available acid chlorides can be applied v...

In the recent work, the reaction mechanism between triphenylphosphine 1, dialkyl acetylenedicarboxylates 2 in the presence of NH-acid, such as 5-aminoindazole 3 were investigated theoretically. Quantum mechanical studies were performed for evaluation of potential energy surfaces of all structures participated in the reaction mechanism both in gas phase and in dichloromethane. The first step of ...

The reaction of ferrocenyldiphenylphosphine with styrene oxide in ethanol gives, as the major product, ferrocenyl(phenyl)(l,2-diphenylethyl)phosphine oxide (5, R = Ph), the result of a rearrangement involving phenyl migration from phosphorus to adjacent carbon in the decomposition of a vinylphosphonium ion arising from protonation and subsequent elimination of water from the initially-formed ph...

protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and acetylenic esters, by nh-acids such as azathioprine, imidazole or theophylline leads to the formation of vinyltriphenylphosphonium salts, which undergo a michael addition reaction with a conjugate base to produce phosphorus ylides. silica nanoparticles (silica nps were prepared by therm...