1035978-71-2Relevant articles and documents
Ligand effects in chromium diphosphine catalysed olefin co-trimerisation and diene trimerisation
Bowen, Lucy E.,Charernsuk, Manutsavin,Hey, Thomas W.,McMullin, Claire L.,Orpen, A. Guy,Wass, Duncan F.
, p. 560 - 567 (2010)
A series of symmetric and unsymmetric N,N-bis(diarylphosphino)amine ('PNP') ligands (Ar2PN(R)PNAr′2: R = Me, Ar2 = o-anisyl, Ar′2 = Ph, 1, R = Me, Ar2 = o-tolyl, Ar′2 = Ph, 2, R = Me, Ar2 = Ph(o-ethyl), Ar′2 = Ph, 3, R = Me, Ar2 = Ar′2 = o-anisyl, 4, R = iPr, Ar2 = Ar′2 = Ph, 5) and symmetric N,N′-bis(diarylphosphino)dimethylhydrazine ('PNNP') ligands (Ar2PN(Me)N(Me)PAr2: Ar2 = o-tolyl, 6, Ar 2 = o-anisyl, 7) have been synthesised. Catalytic screening for ethene/styrene co-trimerisation and isoprene trimerisation was performed via the in situ complexation to [CrCl3(THF)3] followed by activation with methylaluminoxane (MAO). PNNP catalytic systems showed a significant increase in activity and selectivity over previously reported PNP systems in isoprene trimerisation. Comparing the symmetric and unsymmetric variants in ethene and styrene co-trimerisation resulted in a switch in selectivity, an unsymmetric catalytic (o-anisyl)2PN(Me)PPh 2 (1) ligand system affording unique incorporation of two styrenic monomers into the co-trimer product distribution differing from the familiar two ethene and one styrene ω-substituted alkenes. Complexes of the type [(diphosphine)Cr(CO)4] 8-11 were also synthesised, the single-crystal X-ray diffraction of which are reported. We propose the mechanisms of these catalytic transformations and an insight into the effect of the ligand series on the chromacyclic catalytic intermediates. The Royal Society of Chemistry.
LIGANDS AND CATALYST SYSTEMS FOR THE OLIGOMERIZATION OF OLEFINIC MONOMERS
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Page/Page column 39-40, (2008/12/06)
The present invention relates to a ligand having the general formula (I) : (R1) 2P-P(R1)m(R2)n=N(R3) (I) wherein R3 is selected from hydrogen, a hydrocarbyl group, a substituted hydrocarbyl group, a heterohydrocarbyl group, a substituted heterohydrocarbyl group, a silyl group or derivative thereof; the R1 groups are independently selected from an optionally substituted aromatic group bearing a polar substituent on at least one of the ortho-positions; and the R2 groups are independently selected from hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl and substituted heterohydrocarbyl groups with the proviso that when the group is aromatic it does not contain a polar substituent at any of the ortho-positions, with the proviso that m is 0 or 1, n is 1 or 2 and the total of m + n is 2. The present invention also relates to catalyst systems and a process for the simultaneous trimerization and tetramerization of olefinic monomers using said ligands.
