Subject phosphorus compounds

C-Chiral amino phosphorus compounds, particularly 1-amino- and 2-aminoalkanephosphonic acids, have been a subject of interest for organic chemists due to their interesting biological activity7 Among many methods of their... 

The desulphurization of disulphides by tervalent phosphorus compounds has been the subject of a review.70 The light-induced desulphurization of benzylic sulphides by phosphites has found further use in the synthesis of cyclophanes which exhibit the formation of intramolecular charge-transfer complexes, e.g. (61) and (62).71... 

The arrangement of the syntheses in the first part of Volume XIV is divided into three chapters, namely, Phosphorus Compounds, Non-Transition-Metal Compounds, and Transition-Metal Compounds. The reader is advised to seek particular compounds in the subject or formula indexes. The indexes at the end of this volume are cumulative from Volume XI through Volume XIV. 

The chemistry of trivalent phosphorus compounds in which phosphorus is one or two coordinate is rapidly developing. These systems contain sp or sp2 hybridized phosphorus and multiple TT-bonds between P and other elements and until 1964 it was believed that bond formation involving ptr-pir overlap was unfavourable. Subsequently certain -P=C systems resulted from the use of charged ( 1, 2, 3) and or delocalized systems (4J but it is only in the past few years that successful syntheses of phospha-alkenes, R2C=PR , and phospha-alkynes, RC=P, have been reported. These novel compounds are the subject of this paper. 

Although chemistry of unusually hybridized phosphorus compounds has been the subject of one of the most exciting areas in the last ten years, only a few papers report investigations on tricoordinated pentavalent phosphorus derivatives (1 - 3). 

There are several allotropic forms of elemental phosphorus, the most common being the white, red, and black forms. Red phosphorus, which itself includes several forms, is obtained by heating the white form at 400 °C for several hours. An amorphous red form may also be prepared by subjecting white phosphorus to ultraviolet radiation. In the thermal transformation, several substances function as catalysts (e.g., iodine, sodium, and sulfur). Black phosphorus appears to consist of four different forms. These are obtained by the application of heat and pressure to the white form. The major uses of elemental phosphorus involve the production of phosphoric acid and other chemicals. Red phosphorus is used in making matches, and white phosphorus has had extensive use in making incendiary devices. Several of the important classes of phosphorus compounds will be discussed in later sections. 

Inhibition of the cholinesterase activity of the blood is the most sensitive means now available, with the possible exception of the inhibition of the esterase activity of the liver, for detecting the absorption of an organic phosphorus compound that is known to be capable of inducing this effect. The values indicative of cholinesterase activity are shown in Tables III and V. All subjects were exposed to the recommended dosage (one Vaporizer per 1000 cubic feet) except subjects 15 and 16, who were exposed to resin strips that contained no dichlorvos. 

Besides processes (1) and (2), the reader should be aware that nucleophilic attacks on alkynes are treated in other chapters of this book, dealing with rearrangements, cyclizations, polyacetylenes, cyclic acetylenes and perhaps others. A number of publications overlap with ours in different ways and at different levels -. They treat individual alkynes or families " , e.g. acetylene, diacetylenes , acetylene dicarboxylic esters haloacetylenes , alkynyl ethers and thioethers > ynamines , fluoro-alkynes ethynyl ketpnes , nitroalkynes , etc. synthetic targets, e.g. pyrazoles , if-l,2,3-triazoles , isothiazoles , indolizines S etc. reagents, e.g. nitrones , lithium aluminium hydride , heterocyclic A -oxides - , azomethine ylids - , tertiary phosphorus compounds , miscellaneous dipolar nucleophiles - , etc. The reader will appreciate that all of these constitute alternate entries into our subject. 

The catalyst was subjected to chemical anal3rsis, dissolution in a dilute solution of hydrochloric acid. X-ray diffraction analysis, and DTA. Inspection of these analytical data leads to the conclusion that the main constituent of this catalyst is an amorphous solid solution composed of metallic nickel and the nickel-phosphorus compound of formula Nii.gP, the overall composition of which is NirNii.sP = 2.7 1. 

In spite of this only since 1950 was more closely looked at the direct synthesis of organic phosphorus compounds starting from elemental phosphorus. Rauhut, in his thorough review in 1963 on this subject included 34 references. A year later, Grayson lectured on tliis subject Since that time the number of references concerning the synthesis of organic phosphorus compounds from phosphorus has more than quadrupled ( 160) which attests to the lively interest in tlris field. 

It is the purpose of this review to summarize all the syntheses of organic phosphorus compounds which used elemental phosphorus as a starting material. The literature concerning the subject of this review is covered through January 1, 1971, including patent literature so far as abstracts are available in Chemical Abstracts. 

Secondary phosphites and thiophosphites react with silylketens to give vinylphosphonates (58), presumably through rearrangement of (59). The reactions of keten dimers with tervalent phosphorus compounds are much more complicated and have been the subject of extensive study by Bentrude... 

In view of the fascinating potential of phosphorus compounds, it is of substantial interest to develop a deeper understanding and presentation of their chemistry. In this volume leading scientists present modern research trends in seven comprehensive reviews providing a deep insight into the specific subjects. 

The use of nitrogen and phosphorus compounds, particularly as fertilisers, is likely to increase throughout the present century (Chapter 12.2). This will be necessary in order to feed the rapidly expanding world population, and the ecology of these two elements has become a subject of major importance. 

Organophosphines (6.21), like most trivalent phosphorus compounds, are usually very reactive substances. They are strongly nucleophilic - more so than the corresponding amines. Many organophosphines possess an unpleasant odour similar to that of parent phosphine, PHj itself, and they are rather toxic, particularly the lower members which are liquids at room temperature. AU phosphines are subject to oxidation and the simple mono and di alkylphosphines have a great affinity for atmospheric oxygen. Trimethylphosphine vapour is spontaneously inflammable in air. 

Speculations have been and are being made about the future use of DNA in nanotechnology and electronic circuitry [1,2] (Chapter 11.6). Nanoscale electronics, now an up and coming subject, has included studies on several phosphorus compounds [3]. 

H3PO3 is more clearly described with the structural formula HP0(0H)2. This species exists in equilibrium with a minor tautomer P(0H)3. IUPAC recommendations, 2005, are that the latter is called phosphorous acid, whereas the dihydroxy form is called phosphonic acid. Only the reduced phosphorus compounds are spelled with an "ous" ending. Other important oxyacids of phosphorus are phosphoric acid (H3PO4) and hypophosphorous acid (H3PO2). The reduced phosphorus acids are subject to similar tautomerism involving shifts of H between O and P. 

Solvate formation between uranyl salts and acid organo-phosphorus compounds, eg. mono- and dl-alkyl phosphoric acids has been the subject of some Investigation. 

A wide variety of animal species are subjected to the administration of drugs during their lifetime.The various animal species can encounter drugs and other dietary additives by different routes and this is dependent on the environment in which they are kept. Intensively reared animals tend to have considerable consistency in the components of their diets and thus are much less likely to encounter the range of naturally produced compounds that extensively produced animals encounter. The desire for less expensive dietary constituents and increased efficiency of use has induced feed manufacturers and producers to add enzyme supplements to diets of most farmed animals to reduce the negative effects of indigestible dietary carbohydrates, refactory proteins and unavailable minerals such as phosphorus. This use of dietary additives to improve nutrient utilization and environmental consequences of feeding animals intensively has been the subject of intense research activity in the last five years. " The... 

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