B. Anionic Ligands 302 IX. Group 9 Catalysts 302 X. Group 10 Catalysts 303 A. Neutral Ligands 303 1. R-Diimine and Related Ligands 303 2. Other Neutral Nitrogen-Based Ligands 304 3. Chelating Phosphorus-Based Ligands 304 B. Monoanionic Ligands 305 1. [PO] Chelates 305 2. [NO] Chelates 306 3. Other Monoanionic Ligands 306 4. Carbon-Based Ligands 306 XI. Group 11 Catalysts 307 XII. Group 12 Catalysts 307 XIII. Group 13 Catalysts 307 XIV. Summary and Outlook 308 XV. Glossary 308 XVI. References 308

/pdf/advances-in-non-metallocene-olefin-polymerization-catalysis-abl2neq5j1.pdf

Advances in non-metallocene olefin polymerization catalysis.

FI catalysts for olefin polymerization--a comprehensive treatment.

Seven titanium complexes bearing fluorine-containing phenoxy−imine chelate ligands, TiCl2{η2-1-[C(H)NR]-2-O-3-tBu-C6H3}2 [R = 2,3,4,5,6-pentafluorophenyl (1), R = 2,4,6-trifluorophenyl (2), R = 2,6-difluorophenyl (3), R = 2-fluorophenyl (4), R = 3,4,5-trifluorophenyl (5), R = 3,5-difluorophenyl (6), R = 4-fluorophenyl (7)], were synthesized from the lithium salt of the requisite ligand and TiCl4 in good yields (22%−76%). X-ray analysis revealed that the complexes 1 and 3 adopt a distorted octahedral structure in which the two phenoxy oxygens are situated in the trans-position while the two imine nitrogens and the two chlorine atoms are located cis to one another, the same spatial disposition as that for the corresponding nonfluorinated complex. Although the Ti−O, Ti−N, and Ti−Cl bond distances for complexes 1 and 3 are very similar to those for the nonfluorinated complex, the bond angles between the ligands (e.g., O−Ti−O, N−Ti−N, and Cl−Ti−Cl) and the Ti−N−C−C torsion angles involving the phenyl on the im...

Living Polymerization of Ethylene Catalyzed by Titanium Complexes Having Fluorine-Containing Phenoxy−Imine Chelate Ligands

Azines, which are six-membered aromatic compounds containing one or more nitrogen atoms, serve as ubiquitous structural cores of aromatic species with important applications in biological and materials sciences. Among a variety of synthetic approaches toward azines, C–H functionalization represents the most rapid and atom-economical transformation, and it is advantageous for the late-stage functionalization of azine-containing functional molecules. Since azines have several C–H bonds with different reactivities, the development of new reactions that allow for the functionalization of azines in a regioselective fashion has comprised a central issue. This review describes recent advances in the C–H functionalization of azines categorized as follows: (1) SNAr reactions, (2) radical reactions, (3) deprotonation/functionalization, and (4) metal-catalyzed reactions.

C–H Functionalization of Azines

The propylene polymerization behavior of a series of Ti complexes featuring fluorine-containing phenoxy−imine chelate ligands is reported. The Ti complexes combined with methylalumoxane (MAO) can be catalysts for living and, at the same time, stereospecific polymerization of propylene at room temperature or above. DFT calculations suggest that the attractive interaction between a fluorine ortho to the imine nitrogen and a β-hydrogen of a growing polymer chain is responsible for the achievement of room-temperature living propylene polymerization. Although the Ti complexes possess C2 symmetry, they are capable of producing highly syndiotactic polypropylenes. 13C NMR is used to demonstrate that the syndiotacticity is governed by a chain-end control mechanism and that the polymerization is initiated exclusively via 1,2-insertion followed by 2,1-insertion as the principal mode of polymerization. 13C NMR spectroscopy also elucidated that the polypropylenes produced with the Ti complexes possess regio-block stru...

Syndiospecific living propylene polymerization catalyzed by titanium complexes having fluorine-containing phenoxy-imine chelate ligands.

Living Polymerization of α-Olefins: Catalyst Precursor Deactivation via the Unexpected Cleavage of a B−C6F5 Bond

Bulky Chelating Diamide Complexes of Zirconium: Synthesis, Structure, and Reactivity of d0 Alkyl Derivatives

The reaction of RHN(CH 2 ) 3 NHR ( 1a , b ) ( a , R=2,6- i Pr 2 C 6 H 3 ; b , R=2,6-Me 2 C 6 H 3 ) with 2 equiv of BuLi followed by 2 equiv of ClSiMe 3 yields the silylated diamines R(Me 3 Si)N(CH 2 ) 3 N(SiMe 3 )R ( 3a , b ). The reaction of 3a , b with TiCl 4 yields the dichloride complexes [RN(CH 2 ) 3 NR]TiCl 2 ( 4a , b ) and two equiv of ClSiMe 3 . An X-ray study of 4a (P2 1 /n, a =9.771(1) A, b =14.189(1) A, c =21.081(2) A, β =96.27(1)°, V =2905.2(5) A 3 , Z =4, T =25°C, R =0.0701, R w =0.1495) revealed a distorted tetrahedral geometry about titanium with the aryl groups lying perpendicular to the TiN 2 -plane. Compounds 4a , b react with 2 equiv of MeMgBr to give the dimethyl derivatives [RN(CH 2 ) 3 NR]TiMe 2 ( 5a , b ). An X-ray study of 5b (P2 1 2 1 2 1 , a =8.0955(10) A, b =15.288(4) A, c =16.909(3) A, V =2092.8(7) A 3 , Z =4, T =23°C, R =0.0759, R w =0.1458) again revealed a distorted tetrahedral geometry about titanium with titanium–methyl bond lengths of 2.100(9) A and 2.077(9) A. These titanium dimethyl complexes are active catalysts for the polymerization of 1-hexene, when activated with methylaluminoxane (MAO). Activities up to 350,000 g of poly(1-hexene)/mmol catalyst·h were obtained in neat 1-hexene. These systems actively engage in chain transfer to aluminum. Equimolar amounts of 5a or 5b and B(C 6 F 5 ) 3 catalyze the living aspecific polymerization 1-hexene. Polydispersities ( M w / M n ) as low as 1.05 were measured. Highly active living systems are obtained when 5a is activated with {Ph 3 C} + [B(C 6 F 5 ) 4 ] − . A primary insertion mode (1,2 insertion) has been assigned based on both the initiation of the polymer chain and its purposeful termination with iodine.

Chelating diamide complexes of titanium: new catalyst precursors for the highly active and living polymerization of α-olefins

The reaction of RFfN(CH 2 ) 3 NHR (2.3a,b) ( a, R = 2 , 6 M e 2 C 6 H 3 ; b, R = 2,6iPr 2 C6H 3 ) with two equivalents of butyl lithium (BuLi) followed by two equivalents of ClSiMe 3 yields the silylated diamines R(Me3Si)N(CH2)3N(SiMe3)R (2.9a,b). The reaction of 2.9a,b with T i C l 4 yields the dichloride complexes [RN(CH 2)3NR]TiCl2 (2.10a,b) and two equivalents of ClSiMe 3 . An X-ray study of 2.10b (P2,/n, a = 9.771(1) A , b = 14.189(1) A , c = 21.081(2) A , (3 = 96.27(1)°, V = 2905.2(5) A 3 , Z = 4, T = 25°C, R = 0.0701, Rv = 0.1495) revealed a distorted tetrahedral geometry about titanium with the aryl groups lying perpendicular to the TiN2-plane. Complexes 2.10a,b react with two equivalents of MeMgBr to give the dimethyl derivatives [RN(CH 2 ) 3 NR]TiMe 2 (2.11a,b). An X-ray study of 2.11a (P2 12 12 1, a = 8.0955(10) A , b = 15.288(4) A , c = 16.909(3) A , V = 2092.8(7) A 3 , Z = 4, T = 23°C, R = 0.0759, Rw = 0.1458) again revealed a distorted tetrahedral geometry about titanium with titanium-methyl bond lengths of 2.100(9) A and 2.077(9) A . These titanium dimethyl complexes are active catalyst precursors for the polymerization of a-olefins, when activated with methylaluminoxane (MAO). Activities up to 350,000 g of poly(lhexene)/mmol catalyst*h were obtained in neat 1-hexene at 68 °C. These systems actively engage in chain transfer to aluminum. Equimolar amounts of 2.11a or 2.11b and B ( C 6 F 5 ) 3 catalyze the living polymerization a-olefins. Polydispersities ( M ^ M j J as low as 1.05 were measured. Highly active living systems are obtained when 2.11a is activated with {Ph3C}+[B(C6F5)4]_. A primary insertion mode (1,2 insertion) has been assigned based on isotopically labeling the initiator and purposeful termination of the polymer chain with iodine. The addition of a pentane solution of complexes 2.11a,b to a pentane solution of B(C6F5)3 at 23 °C yields an insoluble yellow-orange solid (2.52a,b) in nearly quantitative yield. Complexes 2.52a,b are catalysts for the living polymerization of 1-hexene at 23°C. In the absence of monomer, complex 2.52b slowly evolves methane over the course of several

John D. Scollard

Papers

Living Polymerization of α-Olefins: Catalyst Precursor Deactivation via the Unexpected Cleavage of a B−C6F5 Bond

Bulky Chelating Diamide Complexes of Zirconium: Synthesis, Structure, and Reactivity of d0 Alkyl Derivatives

Chelating diamide complexes of titanium: new catalyst precursors for the highly active and living polymerization of α-olefins

Chelating diamide complexes of titanium, zirconium and scandium : new polymerization catalysts based on non-cp ligand environments