3676-96-8Relevant academic research and scientific papers
Selectivity effects in zirconium-catalyzed heterodehydrocoupling reactions of phosphines
Ghebreab, Michael B.,Costanza, Sierra,Waterman, Rory
, p. 668 - 670 (2016/04/20)
Zirconium compounds are known to dehydrocouple phosphines catalytically. An exploration of the factors that may promote selective heterodehydrocoupling was performed, revealing that steric factors are important but do not provide substantial selectivity. It was observed that 5-(Me3SiNCH2CH2)2N(CH2CH2NSiMe2CH2)Zr (1) may be sufficiently Lewis acidic to perform Lewis acid or frustrated Lewis pair catalysis.
Selectivity effects in zirconium-catalyzed heterodehydrocoupling reactions of phosphines
Ghebreab, Michael B.,Costanza, Sierra,Waterman, Rory
, p. 668 - 670 (2016/04/20)
Zirconium compounds are known to dehydrocouple phosphines catalytically. An exploration of the factors that may promote selective heterodehydrocoupling was performed, revealing that steric factors are important but do not provide substantial selectivity. It was observed that 5-(Me3SiNCH2CH2)2N(CH2CH2NSiMe2CH2)Zr (1) may be sufficiently Lewis acidic to perform Lewis acid or frustrated Lewis pair catalysis.
Differences in the stability of zirconium(IV) complexes related to catalytic phosphine dehydrocoupling reactions
Ghebreab, Michael B.,Newsham, David K.,Waterman, Rory
supporting information; experimental part, p. 7683 - 7685 (2011/09/20)
Relating to the catalytic dehydrocoupling of secondary phosphine substrates, zirconium phosphide complexes supported by triamidoamine and pentamethylcyclopentadienyl ligands exhibit different stability that is attributed to β-hydride elimination.
Reactivity of phosphiranes toward nucleophiles: Theoretical and experimental investigations
Coote, Michelle L.,Krenske, Elizabeth H.,Maulana, Ilham,Steinbach, Joerg,Wild, S. Bruce
, p. 178 - 181 (2008/09/18)
The thermodynamic and kinetic parameters for the reaction of 1-methylphosphirane with dimethylphosphide (PMe2-), proceeding via attack at the ring phosphorus atom to give Me2P- PMe- plus ethylene, were calculated at the G3(MP2)-RAD(+) level. The rate constant for this mechanism (k= 1.1 × 10-13 L mol -1 s-1 at 25°C) is seven orders of magnitude greater than that for the previously studied mechanism involving attack at carbon. Experimental investigations with 1-phenylphosphirane gave consistent results: Treatment with LiPMePh yielded no detectable polymer, and quenching with MeI gave the known diphosphine (R*, R*)-(±)/(R*,S*)- MePhP-PMePh.
Phosphinocyclopentadienide via Cyclopentadienylphosphide
Schmidpeter, Alfred,Zirzow, Karl-Heinz
, p. 977 - 983 (2007/10/02)
Lithiumorganyls RLi (R = Me, Bu, Ph) add to (PhP)5 in successive degradation and disproportionation equilibria depending on the ratio of the reactants.At -70 deg C (R = Me) disproportionation is blocked and (PhP)4R(-) and (PhP)3R(-) can be detected.With excess RLi monophosphides PhPR(-) are formed.CpNa with the help of a crown ether degrades (PhP)5 or substitutes cyanide from PhPCN(-) to give an equilibrium mixture of (PhP)nCp(-) anions, which stabilize by proton shifts: In case of n = 1 and 2 a shift from the Cp unit to the terminal phosphorus results in the formation of the phenylphosphino- and diphenyldiphosphino-cyclopentadienide anion, in case of n = 3 two proton shifts within the Cp unit result in a cyclopenteno-1,2,3-triphospholene allylic anion. - Keywords: Cyclophosphane, Cyclopentadienide, Nucleophilic Degradation, 31P NMR Spectra
Phosphorus-Phosphorus Nuclear Spin Coupling in Tetraorganobiphosphines and Some of Their Derivatives
McFarlane, H. Christina E.,McFarlane, William,Nash, John A.
, p. 240 - 244 (2007/10/02)
The signs and magnitudes of (31)P-(31)P and (31)P-H spin coupling constants in tetraorganobiphosphines RR'PPRR' with Me, Ph, and/or Bu-t as substituents, and in their sulphides and selenides RR'P(X)P(X)RR' (X = S or Se), have been determined by (1)H- heteronuclear double resonance.Large variation in (1)J((31)P-(31)P) arise as a result of changes in the phosphorus hybridization and/or effective nuclear charge, and smaller variations as a result of changes in the position of rotameric equilibrium in the gauche conformers of the biphosphines.
