The Effect of Trifluoroethoxy Groups on the Structures of Eight-Membered Ring-Containing Cyclic Phosphites
作者:Natalya V. Timosheva、A. Chandrasekaran、Robert R. Holmes
DOI:10.1080/10426500600754810
日期:2006.9.1
in a syn conformation that a allowed a sulfur donor interaction to the phosphorus atom, whereas for phosphite 2, the eight membered sulfonyl containing ring was in an anti conformation that did not allow a donor interaction to phosphorus from the oxygen atom of the sulfonyl group. Structural comparisons are made with related cyclic phosphites and phosphates having donor atoms in eight-membered rings
phosphororganische Antioxidantien. XII. Synthesen und NMR-Spektren phosphororganischer Antioxidantien und verwandter Verbindungen
作者:T. K�nig、W. D. Habicher、U. H�hner、J. Pionteck、C. R�ger、K. Schwetlick
DOI:10.1002/prac.19923340407
日期:——
The syntheses of various aliphatic, aromatic, sterically hindered, and cyclic organophosphorus compounds (phosphorous acid esters, ester chlorides and ester amides, hydrogen phosphites, phosphonates and phosphates) are reported, and general procedures for preparation are given.The compounds synthesized were investigated by means of P-31-, H-1- and C-13-n.m.r. spectroscopy, and the chemical shifts measured are listed.
Isomeric Intraconversion among Penta- and Hexacoordinate Cyclic Oxyphosphoranes via Oxygen Atom Coordination<sup>1</sup><sup>,</sup><sup>2</sup>
作者:A. Chandrasekaran、Roberta O. Day、Robert R. Holmes
DOI:10.1021/ja9722988
日期:1997.11.1
The synthesis of a series of cyclic pentaoxyphosphoranes containing a sulfonyl group was carried out by the reaction of either P(OCH2CF3)(3) or P(OPh)(3) with the appropriate diol in an oxidative addition reaction: O2S[(t-Bu)MeC6H2O](2)P(OCH2CF3)(3) (1), O2S[(t-BU)MeC6H2O](2)P(OPh)(3) (2), O2S[(t-Bu)(2)C6H2O](2)P(OCP2CF3)(3) (4), and O2S[(t-Bu)(2)C6H2O](2)P(OPh)(3) (5). Reaction of 2 with catechol yielded O2S[(t-Bu)MeC6H2O](2)P(OPh)(C6H4O2) (3). X-ray studies provided the structures of 1-5, although 1 was badly disordered. The geometries of 2, 3, and 5 are octahedral due to P-O coordination provided by the sulfonyl group, whereas 1 and 4 are trigonal bipyramidal, Solution P-31, H-1, and F-19 NMR spectra demonstrate that 1 and 4 exist in isomeric modifications, These are formulated as a pentacoordinate structure, as in the solid state, and a hexacoordinate structure, This represents the first study establishing intramolecular intraconversion between penta-and hexacoordinate isomers of phosphorus. An activation free energy of 17 kcal/mol for the exchange process for 1 and I was obtained from variable temperature H-1 NMR spectra.