Structurally uniform 1-hexene, 1-octene, and 1-decene oligomers: Zirconocene/MAO-catalyzed preparation, characterization, and prospects of their use as low-viscosity low-temperature oil base stocks

Synthesis of Heteroarene‐Fused Cyclopentadienes and Related Compounds Suitable for Metallocene Preparation

“…Heterocenes have already shown unique catalytic characteristics in the homopolymerization of propylene and 1-butene (e. g., cyclopentadithiophene complexes), [23-25, 46,47,49,268-270] and in ethylene/α-olefin copolymerization (e. g., indenoindole derivatives). [38,41,42,62,208,218,[271][272][273] Very recently, we demonstrated that thiopentalene complexes allow the preparation of structurally uniform α-olefin oligomers, [58] and proved experimentally the advantage of heterocenes over the cyclopentadienyl ligands in traditional zirconocene catalysts in the polymerization of higher α-olefins. [26] However, we and our colleagues have no more than skimmed the surface of this direction in the design of metallocene catalysts.…”

“…[56,117] Assuming that the product yields in the reaction of the thiophenes with the unsaturated acids would be poorly reproducible, this three-stage approach was also used in the synthesis of 105. [58] Note that 5-methyl-4H-cyclopenta[b]thiophen-6(5H)-one 101 was first obtained in 78% isolated yield in this way, [118] and the yield was later optimized at 81%. [108] Thienyl vinyl ketones and the corresponding cyclopentenones were also obtained using an alternative approach based on synthetically available 2-thienylcarboxylic acids as starting compounds (Scheme 17A).…”

“…Me Me PPA 70 [114] -----PPA 75 [115] 109 Me Ph H Me PPA 82-89 [20,116] thiophen-6(5H)-ones using Mannich reaction. [56,58,117,118] ketone 121 (Scheme 17C). [81] Note that other acid catalysts can be used in the cyclization of thienyl vinyl ketones, such as Sc(OTf) 3 .…”

“…[20,21,[23][24][25][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56] Indeed, heterocene catalysts are becoming relevant again. [26,27,[57][58][59][60][61][62][63][64][65][66][67][68] In the present review, the synthetic approaches to heterocycles that can form η 5 -coordinated ligands are presented and discussed. This work complements and significantly expands previously published reviews on the synthesis of indenoindoles, [4] hetarenopentalenes, [69] Ilya E. Nifant (CSc., 1995) and further research in the field of the zirconocenecatalyzed polymerization of αolefins (DSc., 2014).…”

The structural diversity of heterocycle-fused potassium cyclopentadienides

“…Such ligands have been successfully applied in the design of an effective epoxidation catalyst; 9 sandwich and half-sandwich complexes of group 4 metals (so-called "heterocenes") represent next-generation metallocene catalysts for a-olen polymerization. [10][11][12][13][14][15] Recently, we demonstrated the high efficiency of cyclopenta[b] thiophene Zr complexes in oligomerization of C 6 -C 10 a-olens, 16 and the promising catalytic properties of Zr ansa-complexes based on cyclopenta[1,2-b:4,3-b 0 ]dithiophene, indeno [1,2-b] indole and indeno [2,1-b]indole (Scheme 2, top) in polymerization of 1-octene. 17 In our experiments, heterocenes outperformed traditional cyclopentadienyl, indenyl and uorenyl sandwich Scheme 1 Donor heterocyclefused cyclopentadienes.…”