Transition metals Organophosphorus compounds

Indeed, these reactions proceed at 25 °C in ethanol-aqueous media in the absence of transition metal catalysts. The ease with which P-H bonds in primary phosphines can be converted to P-C bonds, as shown in Schemes 9 and 10, demonstrates the importance of primary phosphines in the design and development of novel organophosphorus compounds. In particular, functionalized hydroxymethyl phosphines have become ubiquitous in the development of water-soluble transition metal/organometallic compounds for potential applications in biphasic aqueous-organic catalysis and also in transition metal based pharmaceutical development [53-62]. Extensive investigations on the coordination chemistry of hydroxymethyl phosphines have demonstrated unique stereospe-cific and kinetic propensity of this class of water-soluble phosphines [53-62]. Representative examples outlined in Fig. 4, depict bidentate and multidentate coordination modes and the unique kinetic propensity to stabilize various oxidation states of metal centers, such as Re( V), Rh(III), Pt(II) and Au(I), in aqueous media [53 - 62]. Therefore, the importance of functionalized primary phosphines in the development of multidentate water-soluble phosphines cannot be overemphasized. 

Phosphinidenes [1] are low-valent organophosphorus compounds that have attracted attention since the early 1980s when they were first discovered [2]. They are known in two classifications, one being the six-electron singly substituted phosphorus species (A) and the other in which the phosphorus atom carries an additional ri -stabifizing group, typically, but not necessarily, a transition metal group (B). Much has been learned about the reactivities of the complexed phos-... 

The following chapter concerns another kind of low-valent organophosphorus compounds, namely phosphinidenes. Little is known about free phos-phinidenes in contrast to the corresponding transition metal complexes. Many new reagents have been generated exhibiting either electrophilic or nucleophilic properties. The reactivity of these carbene-like reagents is evaluated (K. hammer tsma). 

OrganometaUic compounds, of transition metals as catalysts for polymerization of vinyl monomers and olefins, 23 263-325 OrganometaUic transformation, molecular analogs, 38 288, 290-291 Organophosphorus substrates, hydrolysis of, effect of cycloamyloses on, 23 235 Organosilicon compounds, hexacoordinated, 34 155... 

The author hopes that this chapter has convinced the readers of the value of homogeneous catalysis for the synthesis of organophosphorus compounds and for organo-heteroatom compounds in a broader sense. Hydrosilylation and hydroboration are indispensable modern synthetic reactions in this category. The H-P addition reactions herein described joins them as a third member. Although this chapter does not cover, the addition reactions of the S-P and Se-P bonds in thiophosphates [39] and selenophosphates [40] to alkynes also proceed in the presence of transition metal catalysts. In view of the wide use of phosphorus compounds, the new procedures will find practical applications. 

Organonitrosyl reagents, transition metal nitro-syl complexes synthesis, 34 297 Organophosphorus compounds bond lengths in, 5 349... 

Organophosphorus Compounds, Transition Metals and Metal Oxides... 

APPLICATIONS OF TRANSITION METALS AND METAL OXIDES AS CATALYSTS FOR ADSORPTION AND DECOMPOSITION OF ORGANOPHOSPHORUS COMPOUNDS... 

An excellent review has discussed the synthesis of organophosphorus cages employing phosphaalkynes as precursors.68 In order to avoid unnecessary duplication of coverage, the results here reported are restricted to transition-metal-assisted transformations. An intramolecular [2+4] cycloaddition between an 7 -phosphaalkyne and an V-cyclopentadienylli-gand to yield compound 134 is observed during the reaction of complex 114 with lithium cyclopentadienide, as shown in Eq. (29).56c... 

The photochemistry of transition carbonyl complexes of chromium or iron with phosphirane or l//-phosphirene ligands is studied with time-dependent DFT theory to explore the propensity of the excited metal-phosphine-carbonyl complexes to expel their ligands <2003JA3558>. The complexes of these phosphorus heterocycles show similar behavior as carbonyl complexes with the PH3 ligand and they differ mainly in their enhanced a-donating ability. The calculations point that the excited complexes prefer the expulsion of the phosphorus substituents, which can be an alternative method to demetalate transition metal complexes of organophosphorus compounds. 

A variety of anellated azaphospholes have become accessible through facile methods. These compounds have appreciable stability and incorporate several functionalities. In view of this, starting with these compounds, a variety of organophosphorus compounds including their transition metal complexes can be synthesized. Some promising results have already been obtained and it is hoped that this brief report will stimulate further work in this field. 

For the last few years, enormous success has been achieved in the asynunetric synthesis of organophosphorus compounds, primarily for phosphine ligands for transition metal-catalyzed asymmetric reactions, and many articles devoted to the synthesis of chiral organophosphorus compounds have been published. It is therefore interesting to analyze and systematize the data dedicated to asynunetric synthesis of F-chiral organophosphorus compounds that have been published over the last 5-10 years. 

W. Levason, Phosphine complexes of the transition metals, in The Chemistry of Organophosphorus Compounds, F.R. Hartley, Ed., Chapter 15, Vol. 1, WUey, Chichester, 1990. 

Transition Metal Cation Separations by Organophosphorus Compounds in Liquid Membrane Processes... 

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