Ethylene oligomerisation chromium catalysts with unsymmetrical PCNP ligands

Abstract

PCNP diphosphines, in conjunction with Cr(acac)3, are excellent ethylene oligomerisation catalysts with high activity and selectivity towards both 1-hexene and 1-octene formation.

Phospha-Mannich reactions of RPH2, R2PH, and R3P

“…Ar' Ar Yield, % d P , ppm 77 [208] -20.3 (CDCl 3 /MeOH) 66 [208] -20.2 (CDCl 3 /MeOH) 80 [208] -19.7 (CDCl 3 /DMSO) 94 [208] -18.5 (CDCl 3 ) 96 [208] -18.9 (CDCl 3 ) 93 [208] -18.6 (CDCl 3 ) 48 [204] -19.3 (CDCl 3 ) (-)* [208] -19.8 (CDCl 3 /MeOH) 63 [208] -21.5 (CDCl 3 /DMSO) 82 [209,210] -18.4 (CDCl 3 ) 67 [209,210] -18.7 (CDCl 3 ) 61 [209,210] -18.8 (CDCl 3 )…”

Low-Dimensional Architectures in Isomeric cis-PtCl2{Ph2PCH2N(Ar)CH2PPh2} Complexes Using Regioselective-N(Aryl)-Group Manipulation

“…We [11][12][13][14][15][16]29], and others [17,[19][20][21][22], have previously used Mannich condensations as a versatile method for the synthesis of aminomethylphosphines. Accordingly, two equivalents of Ph 2 PCH 2 OH were reacted with one equivalent of the amine, for 24 h at r.t. under N 2 , yielding the desired phenol-substituted ditertiary phosphines 1a-e and 3 (Scheme 1).…”

“…This does leave the two unique amide NH atoms free to form intermolecular interactions, which they do via highly asymmetric, bifurcated H-bonds with the coordinated chloride ligands on adjacent Pt complexes. From H(2) d = 2.60 (11) ring. Again, here the amide NH is involved in the 1D chain propagation (Figure 13), forming a symmetrical bifurcated H-bond with the two coordinated chloride ligands on the adjacent molecule with d = 2.66(15) Å.…”

“…Restraints were applied to these rings and also the two half-occupancy Et 2 O solvent molecules of crystallisation. In 5c• 1 4 H 2 O, atoms Cl(1) and C(3) > C (11), O(1), O(2) and N(1) were modelled as split over two sets of positions with major occupancy 56(4) and 50.9(6)%, respectively and restraints were applied. In 5d•Et 2 O the Et 2 O was modelled as a diffuse area of electron density by the Platon Squeeze procedure and restraints were applied to atoms C(1) > C (10), C(11) > C (22) and N(2) O(2).…”

“…For a number of years, we [11][12][13][14][15][16], and others [17][18][19][20][21][22], have been interested in aminomethylphosphines, readily amenable by Mannich condensation reactions. Such interest stems from the relative ease of accessing P-monodentate ligands based on a P-C-N linker [11,15,16,19,20,22] or P/P-bidentate derivatives bearing a P-C-N-C-P backbone [12][13][14][17][18][19]21]. Previously, we have shown that the N-arene group can be easily tuned with, for example, various H-bonding donor/acceptor sites based on -CO 2 H/OH groups [12][13][14][15][16].…”