Phosphorus functionalization

Following the general trend of this account, monodentate phosphinous amide ligands and bidentate AT-phosphino phosphinous amides or bis(amino-phosphanes) are included in the following discussion, but not other bidentate ligands bearing additional, different phosphorus functionalities, as for instance phosphinous amide-phosphane bidentate ligands. 

Phosphinous amides 47-49 (Scheme 39), closely related to those in the scheme above but with a new scaffold supporting the sulfur and phosphorus functionalities, have been recently reported to catalyze the same reaction [ 166]. 

The first chapter Heterophenes Carrying Phosphorus Functional Groups as Key Structures presents a detailed description of the recent advances made in this field. The recent studies of all-phosphorus-substituted aromatic compounds have revealed some unique properties of these heterocycles. 

Heterophenes Carrying Phosphorus Functional Groups as Key Structures... 

Scheme 2 Heterophenes carrying phosphorus functional groups as key structures...

Quin, L.D. and Littlefield, L.B., Importance of the structure of the phosphorus functionality in allowing dihedral angle control of vicinal 13C-31P coupling. Carbon-13 NMR spectra of 7-substituted bicyclo[2,2,l]heptane derivatives,. Org. Chem., 43, 3508, 1978. 

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... 

To investigate such reactions further, various substituted, phosphorus-rich silylphosphanes are needed as starting compounds. The following investigations aim at the preparation of phosphorus functional tri- and tetraphosphanes, in which particular phosphorus atoms with reactive substituents (H, Li, halogen, SiMe3) are built in, while other phosphorus atoms with equally defined positions remain blocked by alkyl groups. 

Carreira and co-workers (138) successfully applied the Mg(II) ion-mediated nitrile oxide cycloaddition method to the total synthesis of epothilones A and B (Scheme 11.36). The key step in the synthesis was a hydroxyl-directed syn-selective nitrile oxide cycloaddition using a phosphorus-functionalized aliphatic nitrile oxide. This cycloaddition step served not only to introduce a heterocycle-substituted appendage into the skeleton of the epothilones, but also to assemble two... 

This is especially true of the A PA P linkage of which Roesky and his oo-workers have reported a few examples only as recently as 1979/1980 2. — Likewise, a first example of a compound with A P-A P directly bonded has been reported by Richman and Holmes only in 1980 We have undertaken attempts at the synthesis of bifunctional phosphorus compounds involving both P-P bonded systems as well as with phosphorus functions separated by other groups, especially the N,N -dimethylurea group, MeNC( OJNMe The bulk... 

Phosphorus-functionalized homoallyl sulfides have been prepared using either base-promoted yUde generation [ 196] or, more recently, the carbenoid route (Scheme 84) [197]. When diazomethylphosphonate 341 [198] was reacted with allyhc sulfides 342, the rearranged a-phosphorylated sulfides 344... 

Scheme 84 Rearrangement of phosphorus-functionalized sulfonium ylides...

Tp = ti -C7H7, trimpsi = fBuSi(CH2PMc2)j. Cp = n CsMcj, p = oligodentate phosphine coordinating with m of the phosphorus functions dmpe = MejP(CHj)2PMcj, dppe = PhjP(CH2)2PPh2. 1/ if not indicated otherwise. 

Treatment of the phosphorus-functionalized zirconocene dichloride 608 with 2equiv. of MeMgBr affords the dimethyl complex 609, which, on reaction with 0.5 equiv. of PbCl2, gives the monochloro methyl complex 610441 (Scheme 137). Both the dimethyl and the monochloro methyl complexes can insert one molecule of CO to afford products 611, which interconvert between an acyl complex and a phosphonium alkoxide at ambient temperature. 

Tsuge, O., Kanemasa, S., and Suga, H., Synthesis of a new phosphorus-functionalized nitrile oxide, a-(diethylphosphono)acetonitrile oxide, and cycloaddition leading to 3-(diethylphosphonomethyl)-A -isoxazolines, Chem. Lett., 183, 1986. 

Other authors have described the use of the previously seen framework [39]. The grafting of the DIOP ligand (Eqs. 5-7) onto a Merrifield resin was performed by treatment of the insoluble aldehyde 21 with the (+)-diol 22 of the DIOP, leading to the ditosylate 23. This product was then treated with lithium diphenylphos-phide, affording the desired phosphinated resin 24, which contains 0.5 meq/g of phosphorus functions. The reaction with [RhCl(C2H4)2]2 gave an insoluble complex that may be used further in catalysis. 

Polymers bearing a functional group based on diisobutylphosphine sulfide and containing different spacer arms between the polymeric matrix and the phosphorus functional group were synthesized by Sanchez and co-workers from chloromethylated polystyrene (crosslinked with 4% DVB)... 

Tris (tribromoneopentyl) phosphate is used in DSBG s FR-370, an FR that combines halogen and phosphorus functionalities, avoiding the need for any antimony synergist. It is said to be useful for outdoor PP fmniture products exposed to UV, and has the advantage of offering a lower processing temperature than many of its competitors. 

HuUcova-Jurcakova, D., Seredych, M., Lu, G.Q., Kodiweera, N.K.A.C., Stallworth, P.E., Greenbaum, S., and Bandosz, T.J. Effect of surface phosphorus functionalities of activated carbons containing oxygen and nitrogen on electrochemical capacitance. Carbon 2009 47 1576-1584. 

One final consideration has been given to a molecule that contains both nitrogen and phosphorus functions. Such a molecule is shown in Fig. 11. The molecule is tribasic but when titrated with protons only takes up two equivalents of hydrogen ions. The strongest basic center is one of the nitrogens. The position of the second proton is problematical. 

Absorption of Phosphorus Metaboiism of Phosphorus Excretion of Phosphorus Functions of Phosphorus Deficiency Symptoms interreiationships... 

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