Phosphorus compounds Phosphine oxides

A comparison of bromine and phosphorus compounds on the flammability of PET fiber shows phosphorus (as phosphine oxide) to be 3.7 times more effective than bromine (Table 1). No synergy was observed. Nevertheless, phosphorus was shown to be more effective than antimony normally used as a synergist, resulting in a higher oxygen index at a lower concentration (Table 2). 

Bergin E, O Connor CT, Robinson SB, McGarrigle EM, O Mahony CP, Gilheany DG (2007) Synthesis of F-stereogenic phosphorus compounds. Asymmetric oxidation of phosphines under Appel conditions. J Am Chem S[Pg.228]

Phosphines and Phosphonium Salts Pentaco-ordinated and Hexaco-ordinated Compounds Phosphine Oxide and Related Compounds Tervalent Phosphorus Acids Quinquevalent Phosphorus Acids Nucleotides and Nucleic Acids Ylides and Related Compounds Phosphazenes. 

It is widely known that trivalent phosphorus compounds undergo oxidation with air, traces of oxygen, or hydroperoxides, which may be caused by improper storage. Moreover, these and other impurities (also called virulent poisons such as H2S, COS, HCl, and HCN) [154] may be brought in the hydroformylation process by solvents or by the olefin feed, and appropriate measures against it must be taken [155]. Noteworthy, also carboxylic acids inhibit the rate of the hydroformylation, especially in the presence of an excess of free phosphine [156]. 

Although unsynunetrically substituted amines are chiral, the configuration is not stable because of rapid inversion at nitrogen. The activation energy for pyramidal inversion at phosphorus is much higher than at nitrogen, and many optically active phosphines have been prepared. The barrier to inversion is usually in the range of 30-3S kcal/mol so that enantiomerically pure phosphines are stable at room temperature but racemize by inversion at elevated tempeiatuies. Asymmetrically substituted tetracoordinate phosphorus compounds such as phosphonium salts and phosphine oxides are also chiral. Scheme 2.1 includes some examples of chiral phosphorus compounds. 

Well known carbanionic sigmatropic rearrangements, applied to mixed P and S compounds, regio- and/or stereoselectively lead to new (a-sulfanylalkyl) or P-sulfanylaryl) phosphonates, phosphine oxides, or phosphorodiamidates. In these difunctional compounds, chirality can be either introduced on the phosphorus, on the a-carbon, or on the sulfur atom. 

C. By Oxidation.—This year s literature has been notable for attempts to study the details of certain phosphine oxidation reactions. In one such investigation nitric acid was found to oxidize phosphines, or phosphine sulphides, to phosphine oxides with inversion of configuration at phosphorus, whereas dinitrogen tetroxide, in the absence of acid, was found to oxidize the same compounds with predominant retention. The partial racemization observed with the latter reagent was probably due to the racemization of the oxides, since methylphenyl-n-propylphosphine oxide... 

D. Miscellaneous.—A further study of the reactions of diphenyl-phosphine oxide with tetracyclone has confirmed that the reaction yields the oxide (30) under mild, basic conditions, and that the reaction is thermally reversible. The displacement of halogen from phosphorus by amino-compounds has been used in the synthesis of a number of aminofluoro-phosphine oxides (31), and of A-methyl-AA-bis(dichlorophosphinyl)-amine (32). ... 

Nickel and palladium complexes also catalyze the formation of the carbon-phosphorus bonds in phosphorus(V) and phosphorus(III) compounds. Indeed, this chemistry has become a common way to prepare phosphine ligands by the catalytic formation of phosphine oxides and subsequent reduction, by the formation of phosphine boranes and subsequent decomplexation, or by the formation of phosphines directly. The catalytic formation of both aryl and vinyl carbon phosphorus bonds has been accomplished. 

By Reduction. The first known compounds containing a tervalent phosphorus function and an epoxide ring [(37) and (38)] have been prepared by reduction with phenyl-silane of the corresponding phosphine oxides they are quite stable, showing no... 

As a potential class of compounds we came to consider phosphine oxides, reasoning that pentavalent phosphorus compounds are certain not to interact strongly with Ru. 

From the product analyses of PET reactions of trivalent phosphorus compounds such as phosphines and phosphates, it is found that P reacts with nucleophiles such as water and alcohol to yield phosphine oxides and phosphates [92-95]. During a reaction of triphenylphosphines (P(CgH4-X-/ )3 with water to give phosphine oxides 0=P(C6H4-X-/ )3... 

Phosphorus-Substituted Organometallic Compounds From Phosphine Oxides... 

Nitrogen analogs are known for some of these phosphorus compounds, but they are less stable because the resonance is lacking. For example, amine oxides, analogs of phosphine... 

Includes bibliographical references and indexes. Contents v. 1. Primary, secondary, and tertiary phosphines, polyphosphines, and heterocyclic organo-phosphorus(III) compounds—v. 2. Phosphine oxides, sulphides, selenides, and tellurides—v. 3. Phosphonium salts, ylides, and phosphoranes. 

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