Mechanically Induced Solid-State Generation of Phosphorus Ylides and the Solvent-Free Wittig Reaction

Mechanically induced solid-state generation of phosphorus ylides and the solvent-free Wittig reaction.

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...

The Wittig Reaction

The Wittig Reaction

This so-called Wittig reaction has a number of advantages over other olefination methods; in particular, it occurs with total positional selectivity (that is, an alkene always directly replaces a carbonyl group). By comparison, a number of other carbonyl olefination reactions often occur with double-bond rearrangement. In addition, the factors that influence Eand Z-stereoselectivity are well un...

Experimental and Theoretical Study of Stable Phosphorus Ylides Derived from 5-Nitroindazole in the Presence of Different Acetyelenic Esters: Furthure Insight into the Reaction Mechanism

The kinetics of the reactions between triphenylphosphine 1 and dialkyl acetylenedicarboxylates 2, in the presence of a NH-acid such as 5-nitroindazole 3,were studied. Corresponding kinetic parameters to all reactions were evaluated, with the second order rate constant (k) values calculated. Effects of solvent, temperature, and reactant...

Synthesis & Characterization of CaB4O7 Powder by Solid-State Reaction

The synthesis of calcium tetraborate was investigated in a temperature ranging from 800℃ to 900℃ using the solid-state reaction method. The synthesis was done using ammonium tetraborate tetrahydrate as the source of boron. At temperatures of 800 ℃ and 880 ℃, the mixed phases from different compounds were formed. At the optimum temperature of 840℃, the mixed phase was only composed of meta and t...