Phosphoryl compounds, addition

In recent years, the use of a-substituted phosphoryl compounds has mushroomed as they have become recognized as useful analogues of a-substituted carboxyl compounds (including the a-amino acids), as well as materials with their own applications. We will begin here by reviewing the well-established approaches toward such materials, specifically the Abramov and Pudovik reactions, including the associated conjugate addition reactions, and then consider the newer approaches toward such compounds. 

Benzoic acid (271) when reacted with PCI3 yielded an adduct (272) which underwent an Arbuzov rearrangement to the phosphoryl compound (273), which eliminated 3HC1 to give benzoylphosphonic anhydride (274). Addition of water to the reaction mixture converted the anhydride (274) into benzoylphosphonic acid (275), which underwent... 

Addition of Lithium Dialkylcuprates to cr,/3-Unsaturated Phosphoryl Compounds... 

A noteworthy synthetic application for the reaction of J with a,g-unsaturated phosphoryl compounds is represented by the addition involving hitherto unknown (-)-(Sp)-methylphenylvinylphosphine oxide J 2. The resulting tertiary phosphine oxides 13 with saturated carbon chains and known stereochemistry at phosphorus constitute attractive starting materials for the preparation of optically pure phosphines. The organophosphorus substrate 12 was obtained by decarbomenthoxylation of the enantiomeric ester... 

The effect of CCCP on NMR-detected PolyP was investigated in S. cerevisiae grown on lactate (Beauvoit el al., 1991). The cells were incubated in a resting medium in aerobiosis with lactate or glucose or in anaerobiosis with glucose. For each case, in vivo 31P NMR spectroscopy was used to measure the levels of phosphorylated compounds. A spontaneous PolyP breakdown occurred in anaerobiosis and in the absence of CCCP. In aerobiosis, PolyP hydrolysis was induced by the addition of either CCCP or a vacuolar membrane ATPase-specific inhibitor, bafilomycin Al (Beauvoit el al., 1991). 

Dipole Moments. - Dipole moments and molar Kerr constants of complexes of phenols with phosphoryl compounds were studied to establish the structure of the complexes and obtain the parameters pH, A(mK)s, InK and 5o characterising the proton acceptor ability of these compounds. The new parameter A(mK)s, structural additive difference of the molar Kerr constant, made it possible to determine changes of polarity and polarisability of the systems during complex formation. The molecular pyroelectric, 4,8,12-trioxa-12c-phospha-4,8,12,12c-tetrahydrodibenzo[cd,mn]pyrene (61), was found to have a dipole moment of 3.3 0.2 D, the direction of which was unambiguously assigned with respect to the molecular coordinates. ... 

As is evident from the additivity of free-energy changes of sequential reactions, any phosphorylated compound can be synthesized by coupling the synthesis to the breakdown of another phosphorylated compound with a more negative free energy of hydrolysis. For example, because cleavage of Pj from phospho-enolpyruvate (PEP) releases more energy than is needed to drive the condensation of Pj with ADP, the... 

In contrast to the different sulfur and nitrogen species, phosphorus in marine environments occurs almost exclusively in the oxidation state -i-5. Thus, with few exceptions (Schink and Friedrich 2000), bacteria cannot gain energy by the oxidation of reduced phosphorus species and cannot use phosphate as an electron acceptor. Nevertheless, phosphorylation, the addition of a phosphate group to another compound, plays a major... 

A comparative ab initio study [22] on these two alternative reaction pathways concludes that a zwitterionic structure of the type suggested by Westheimer is not a stationary point on the explored potential energy surfaces for the systems H2O + (H0)2P(0)H and H2O + (H0)3P(0). Two types of critical points were found for these model systems. The first type corresponds to transition structures for the concerted addition of water to these phosphoryl compounds (Figure 3.1). 

Indeed, concomitantly to the loss of enzyme activity, there is, as might be expected, a drop in ATP and other phosphorylated compounds. In addition to a loss of dehydrogenase and hexokinase, the concentration of NAD drops rapidly. It is again not known if this results from accelerated breakdown or from a reduced rate of biosynthesis. Those that postulate that the reduced NAD in red cells results from interference with its synthesis have proposed several mechanisms to explain the reduced rate of biosynthesis of NAD, including (1) a reduction in ribose-5-phos-phate resulting from the impaired activity of the hexose monophosphate shunt and(2) a decrease in the activity of the enzymes involved in the biosynthesis of the coenzymes. 

In addition to the monophosphorus phosphoryl and thiophosphoryl compounds discussed above, several poly-phosphoryl and -thiophosphoryl halides have been characterized. Pyrophos-phoryl fluoride, 0=PP2—O—P(=0)p2 (mp —0.1°, bp 72° extrap) and the white crystalline cyclic tetramer [0=P(F)—0)4 were... 

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