Phosphine

About: Phosphine is a research topic. Over the lifetime, 17578 publications have been published within this topic receiving 318568 citations. The topic is also known as: hydrogen phosphide & phosphorated hydrogen.

Mechanism and Activity of Ruthenium Olefin Metathesis Catalysts

Abstract: This report details the effects of ligand variation on the mechanism and activity of ruthenium-based olefin metathesis catalysts. A series of ruthenium complexes of the general formula L(PR3)(X)2RuCHR1 have been prepared, and the influence of the substituents L, X, R, and R1 on the rates of phosphine dissociation and initiation as well as overall activity for olefin metathesis reactions was examined. In all cases, initiation proceeds by dissociative substitution of a phosphine ligand (PR3) with an olefinic substrate. All of the ligands L, X, R, and R1 have a significant impact on initiation rates and on catalyst activity. The origins of the observed substituent effects as well as the implications of these studies for the design and implementation of new olefin metathesis catalysts and substrates are discussed in detail.

Reactions of electron-deficient alkynes and allenes under phosphine catalysis.

Abstract: The development of some new synthetic reactions derived from nucleophilic addition of phosphines to electron-deficient carbon-carbon triple bonds is described. These reactions show that the phosphine plays the role of a nucleophile as well as an excellent leaving group. The central problem is to generate a 1,3-dipole from alkynoates or allenoates (2,3-butadienoates) by interaction with various phosphines. This study illuminates the unusual phenomena and shows how this understanding allows control of the reaction.