Synthesis and characterization of titanium complexes containing the 1-(3-butenyl)-2,3,4,5-tetramethylcyclopentadienyl ligand

Reduction of Bis[η5-(ω-alkenyl)tetramethylcyclopentadienyl]titanium Dichlorides: An Efficient Synthesis of Long-Chainansa-Bridged Titanocene Dichlorides by Acidolysis of Cyclopentadienyl-Ring- Tethered Titanacyclopentanes

“…The use of THF may account for noticeably lower isolated yields of 1 a (39 %) and 1 b (45 % vs. reported yield of 60 % [9] ). Their solution NMR spectra are, in accordance with NMR data for 1 b, [9] indicative of C 2 or mirror symmetry of the molecules with all resonances observed in the expected region. The dark red compounds 1 a ± c are stable in air in the solid state for at least one year.…”

“…Bis[(w-alkenyl)tetramethylcyclopentadienyl]titanium dichlorides [TiCl 2 {h 5 -C 5 Me 4 (CH(Me)CH CH 2 )} 2 ] (1 a), [TiCl 2 {h 5 -C 5 Me 4 (CH 2 CH 2 CHCH 2 )} 2 ] (1 b) and [TiCl 2 {h 5 -C 5 Me 4 -(CH 2 CH 2 CH 2 CHCH 2 )} 2 ] (1 c) were synthesised using the protocol reported by Okuda, du Plooy and Toscano [9] for 1 b, except that the reaction of the corresponding alkenylcyclopentadienyl lithium with [TiCl 3 (THF) 3 ] was carried out in THF and not in 1,2-dimethoxyethane. The use of THF may account for noticeably lower isolated yields of 1 a (39 %) and 1 b (45 % vs. reported yield of 60 % [9] ).…”

“…After cooling to room temperature, nBuLi (Aldrich) in hexane (22.5 mL 1.6 m, 36 mmol) was added from a syringe under vigorous stirring. Yield: 6.6 g (39 %); brown crystalline powder; 1 17, 12.40, 12.69, 12.96, 13.59, 13.68, 13.73 (2 C; Me 4 C 5 ), 17.57,17.73 (CHMe),37.20,37.26 (CHMe),112.61,122.63 (CH 2 ),124.61,125.39,126.52,128.77,129.20,129.45,130.17 (Me 4 (41) [M À Cl] , 311 (9), 310 (9), 309 (41), 308 (17), 307 (57), 272 (14), 227 (10), 219 (8), 218 (14), 217 (18), 216 (9), 213 (10), 190 (16), 189 (100), 161 (10), 148 (9), 147 (49), 135 (11), 134 (27), 133 (45), 121 (7), 120 (8), 119 (49), 105 (12), 91 (15), 55 (22), 41 (16) Reduction of 1 a ± 1 c by magnesium : Complexes 1 a ± 1 c (1 a 0.47 g, 1 b 0.47 g, 1 c 0.50 g; 1.0 mmol) and magnesium (0.24 g, 10 mmol) were placed into an ampoule, which was carefully evacuated on a vacuum line. In another one-liter three-necked flask, the mixture of 5-(1-methyl-2-propenyl)-1,2,3,4-tetramethylcyclopentadienes (19.14 g, 86 mmol) was dissolved in diethyl ether (500 mL) and nBuLi in hexane (59 mL 1.6 m, 90 mmol) was added by a syringe through a septum under stirring, and the resulting white voluminous precipitate suspended in a yellow solution was stirred for 3 h at room temperature.…”

“…[6] Bis[(1-alkylethenyl)cyclopentadienyl]zirconium dichlorides were also used for the syn-thesis of cyclobutane-bridged ansa-metallocene complexes by a photo-induced [22] cycloaddition. [9] However, interaction of the pendant double bond(s) with the titanium atom in all the Ti IV complexes synthesized has not yet been reported. [8] In titanocene chemistry, a number of titanium derivatives including [TiCl 2 {h 5 -C 5 Me 4 (CH 2 CH 2 CH CH 2 )} 2 ] have been prepared and the crystal structure of the dimethyl derivative [TiMe 2 {h 5 -C 5 Me 4 (CH 2 CH 2 CHCH 2 )} 2 ] was determined.…”

Novel Routes to Bidentate Cyclopentadienyl−Alkoxide Complexes of Titanium: Synthesis of (η5-σ-C5R14CHR2CH2CR3R4O)TiCl2

“…Formation of the trimethylsilyl derivative 18 and reaction with titanium tetrachloride gave the asymmetric complex 19 in good yield. There was no sign by NMR of coordination of the alkene moiety to the metal center …”