15917-04-1Relevant academic research and scientific papers
N, N′-bis(diphenylphosphino)diaminophenylphosphine ligands for chromium-catalyzed selective ethylene oligomerization reactions
Dulai, Arminderjit,McMullin, Claire L.,Tenza, Kenny,Wass, Duncan F.
, p. 935 - 941 (2011)
Reaction of 1 or 2 equiv of Ph2PCl with PhP(N(H)R)2 (R = n-propyl) yields Ph2PN(R)P(Ph)N(R)H (1) or Ph 2PN(R)P(Ph)N(R)PPh2 (2), respectively. In contrast, reaction of 1 or 2 equiv of Ph2PCl with PhP(N(H)R)2 (R = isopropyl) yields exclusively Ph2PN(R)P(Ph)N(R)H (3), even under more forcing conditions. Low-temperature NMR spectroscopy and a conformational analysis of Ph2PN(iPr)P(Ph)N(iPr)H (3) reveal the lowest energy conformer to have a close N-H???P interaction of 2.95 A, which we speculate may hinder further reactivity of this molecule. Reaction of 3 with [Cr(CO)6] yields [Cr(3)(CO)4] (5), which has been structurally characterized. Coordination of ligand 3 facilitates its conversion to Ph2PN(iPr)P(Ph)N(iPr)PPh2 (4) while bound to chromium, yielding the complex [Cr(4)(CO)4] (6), which has also been structurally characterized. Ligands 1 and 2, when reacted in situ with [Cr(acac)3] (acac = acetylacetonate) and modified methylalumoxane, and complexes 5 and 6, when activated with Ag[Al(OC4F 9)4] and triethylaluminum, are moderately active and selective catalysts for the selective oligomerization of ethene to 1-hexene and 1-octene.
Synthesis of differently substituted N- and P-aminodiphosphinoamine PNPN-H ligands
Gongoll, Marc,Mueller, Bernd H.,Peitz, Stephan,Aluri, Bhaskar R.,Peulecke, Normen,Spannenberg, Anke,Rosenthal, Uwe,Al-Hazmi, Mohammed H.,Woehl, Anina,Mueller, Wolfgang
, p. 1845 - 1854 (2013/11/06)
On the basis of the known aminodiphosphinoamine ligand Ph 2PN(i-Pr)P(Ph) N(i-Pr)-H (3a), differently substituted aminodiphosphinoamine PNPN-H ligands (3) were prepared. By using different synthetic methods, the N-substituted ligands Ph2/s
