We synthesized a series of Me2Si-bridged ansa-zirconocene complexes coordinated by thiophene-fused cyclopentadienyl and fluorenyl ligands (Me2Si(2-R1-3-R2-4,5-Me2C7S)(2,7-R32C13H6))ZrMe2 (R1 = Me or H, R2 = H or Me, R3 = H, tBu, or Cl) for the subsequent preparation of supported catalysts. We determined that the fluorenyl ligand adopts an η3-binding mode in 9 (R1 = Me, R2 = H, R3 = H) by X-ray crystallography. Further, we synthesized a derivative 15 by substituting the fluorenyl ligand in 9 with a 2-methyl-4-(4-tert-butylphenyl)indenyl ligand, derivatives 20 and 23 by substituting the Me2Si bridge in 12 (R1 = Me, R2 = H, R3 = tBu) and 15 with a tBuO(CH2)6(Me)Si bridge, and the dinuclear congener 26 by connecting two complexes with a –(Me)Si(CH2)6Si(Me)– spacer. The silica-supported catalysts prepared using 12, 20, and 26 demonstrated up to two times higher productivity in ethylene/1-hexene copolymerization than that prepared with conventional (THI)ZrCl2 (21–26 vs. 12 kg-PE/g-(supported catalyst)), producing polymers with comparable molecular weight (Mw, 330–370 vs. 300 kDa), at a higher 1-hexene content (1.3 vs. 1.0 mol%) but a lower bulk density of polymer particles (0.35 vs. 0.42 g/mL).

α-Olefin trimers are used at a bulk scale as top-tier lubricant base oils, with putative future applications as diesel fuels obtainable from renewable ethylene. α-Olefin trimers are conventionally obtained in the cationic oligomerization process, during which a range of n-mers are simultaneously generated alongside severe skeleton rearrangement. In this context, catalysts that can selectively convert α-olefin to its trimers are valuable. However, few examples have been reported. Herein, we report selective α-olefin trimerization catalysts constructed via the modification of the Chevron–Phillips ethylene trimerization catalytic system and avoiding the use of expensive activators, such as methylaluminoxane (MAO), B­(C6F5)3, and [B­(C6F5)4]− salt, despite the typical Chevron–Phillips system being inactive for α-olefin. A catalytic system Cr­(acac)3/[2,5-Me2C4H2N–Al­(iBu)3]−Na+/(iBu)3Al demonstrating high turnover numbers exceeding 10,000 (31 kg/g-Cr for 1-decene), generating trimers selectively without other higher or lower fractions, was developed, confirmed by simulated distillation gas chromatography analysis. The hypothesized η5-pyrrolide chromium active species was partially confirmed by the structure elucidation of [η5-Me2C4H2N–AlMe3]­Cr­(Me)­[CH2C6H4(ortho-NMe2)-κ2 C,N]. The prepared 1-decene trimers (after hydrogenation) exhibited an advantageously higher viscosity index than the commercial product PAO-4.0 (128 vs 123). Fluids demonstrating similar lubricant characteristics to either the 1-decene trimers or PAO-4.0 were obtained by using a 1-octene/1-dodecene blend.

Grignard reagents featuring carbanion characteristics are mostly unreactive toward alkyl halides and require a catalyst for the coupling reaction. With the need to prepare p-(CH2CH)C6H4CH2CH2CH2Cl on a large scale, the coupling reaction of p-(CH2CH)C6H4MgCl with BrCH2CH2CH2Cl was attempted to screen the catalysts, and CuCN was determined to be the best catalyst affording the desired compound in 80% yield with no formation of Wurtz coupling side product CH2CHC6H4–C6H4CHCH2. The p-(CH2CH)C6H4Cu(CN)MgCl species was proposed as an intermediate based on the X-ray structure of PhCu(CN)Mg(THF)4Cl. p-ClC6H4MgCl did not react with sterically encumbered R3SiCl (R = n-Bu or n-octyl). However, the reaction took place with the addition of 3 mol % CuCN catalyst, affording the desired compound p-ClC6H4SiR3. The structures of p-(CH2CH)C6H4CH2CH2CH2MgCl and p-ClC6H4MgCl were also elucidated, which existed as an aggregate with MgCl2, suggesting that some portion of the Grignard reagents were possibly lost in the coupling reaction due to coprecipitation with the byproduct MgCl2. R3SiCl (R = n-Bu or n-octyl) was also prepared easily and economically with no formation of R4Si when SiCl4 was reacted with 4 equiv of RMgCl. Using the developed syntheses, [p-(CH2CH)C6H4CH2CH2CH2]2Zn and iPrN[P(C6H4-p-SiR3)2]2, which are potentially useful compounds for the production of PS-block-PO-block-PS and 1-octene, respectively, were efficiently synthesized with substantial cost reductions.