Organometallic Compounds of the Lanthanides. 158.¹ Alkenyl-Functionalized Cyclopentadienyl Complexes of Yttrium, Samarium, and Lutetium and Their Hydroboration

Abstract

YCl 3 , SmCl 3 , and LuCl 3 react with (tetramethylvinylcyclopentadienyl)lithium (1a), yielding (CH 2 dCHC 5 Me 4 ) 2 Ln(µ-Cl) 2 Li(Et 2 O) 2 (Ln ) Y (2a), Sm (2b), Lu (2c)). LuCl 3 and the analogous potassium salt 1b form oligomeric [(CH 2 dCHC 5 Me 4 ) 2 Lu(µ 3 -Cl) 2 K(THF)] n (3). Methylation of the yttrium complex 2a with MeLi gives (CH 2 dCHC 5 Me 4 ) 2 Y(µ-CH 3 ) 2 Li(THF) (4). Hydroboration of the complexes 2a-c with 9-BBN results in the formation of (C 8 H 14 BCH 2 -CH 2 C 5 Me 4 ) 2 Ln(µ-Cl) 2 Li(THF) 2 (Ln ) Y (5a), Sm (5b), Lu (5c)). The reaction of YCl 3 with 2 equiv of K[C 5 H 4 CHdC 6 H 10 ] (6) or K[C 5 H 4 CHdCMe 2 ] (10) affords the dimeric complexes [(C 6 H 10 dCHC 5 H 4 ) 2 Y(µ-Cl)] 2 (7) and [(Me 2 CdCHC 5 H 4 ) 2 Y(µ-Cl)] 2 (11), whereas SmCl 3 reacts with 2 equiv of 6 or 10, yielding the tris(cyclopentadienyl) derivatives (C 6 H 10 dCHC 5 H 4 ) 3 -Sm(THF) ( 9) and (Me 2 CdCHC 5 H 4 ) 3 Sm(THF) (13), respectively. Methylation of 7 with MeLi yields unstable [(C 6 H 10 dCHC 5 H 4 ) 2 Y(µ-CH 3 )] 2 (7a). SmI 2 and 6 react with formation of (C 6 H 10 d CHC 5 H 4 ) 2 Sm(THF) 2 (8). Hydrolysis during crystallization of 11 caused by some water in the solvent leads to decomposition, forming the oxygen-bridged complex [(Me 2 CdCHC 5 H 4 ) 2 Y-(Et 2 O)] 2 (µ-O) (12). The ansa-lanthanidocene chloride [H 2 CdC(CH 2 C 5 H 4 ) 2 ]LuCl(THF) (15) was prepared from LuCl 3 and the new ligand K 2 [H 2 CdC(CH 2 C 5 H 4 ) 2 ] ( 14). The structures of 2a, 3, 5b, 7, and 12 were determined by single-crystal X-ray diffraction.

New alkenyl-substituted group 4 C-ansa-metallocene complexes. Reactivity of the substituent at the carbon ansa bridge

“…The dialkyl complexes ½MðRÞCHðg 5 -C 5 Me 4 Þðg 5 -C 5 H 4 ÞR 0 2 ] [M = Ti, R = CH 2 =CHCH 2 , R 0 = Me (6), R 0 = CH 2 Ph (7); R = CH 2 C(CH 3 )@CH 2 , R 0 = Me (8), R 0 = CH 2 Ph (9); M = Zr, R = CH 2 CH@CH 2 , R 0 = Me (10), R 0 = CH 2 Ph (11); R = CH 2 C(CH 3 )@CH 2 , R 0 = Me (12), R 0 = CH 2 Ph (13)] have been synthesized by the reaction of the corresponding ansa-metallocene dichloride complexes 2-5 and two molar equivalents of the alkyl Grignard reagent. Compounds 2-5 reacted with H 2 under catalytic conditions (Wilkinson's catalyst or Pd/C) to give the hydrogenation products [M{(R)CH(g 5 -C 5 Me 4 )(g 5 -C 5 H 4 )}Cl 2 ] [M = Ti and R = CH 2 CH 2 CH 3 (14) or R = CH 2 CH(CH 3 ) 2 (15); M = Zr and R = CH 2 CH 2 CH 3 (16) or R = CH 2 CH(CH 3 ) 2 (17)]. The reactivity of 2-5 has also been tested in hydroboration and hydrosilylation reactions.…”

“…Hydroboration at the double bond of the allyl group of the ansametallocene complexes 2-5 was carried out in a similar manner to that published by our group [11d,f] or Erker, Piers or Alt for metallocene complexes of group 4 [14] or Schumann for lantanocene complexes [15]. 9-BBN was used as the reagent with complexes 2-5 to give mainly anti-Markonikov products [M{(9-BBN-CH 2 CH(R)CH 2 )CH(g 5 -C 5 Me 4 )(g 5 -C 5 H 4 )}Cl 2 ] [M = Ti and R = H (18); M = Zr and R = H (19) or R = CH 3 (20)] (Scheme 5).…”

Substituted Ring‐Fused Yttrium Derivatives – X‐ray Crystal Structures of [(L′YCl2·THF)2LiCl·2THF] and [{L′YCl(OH)}6·2THF] (L′ = 2‐Phenyl‐4,5,6,7,8‐hexahydroazulenyl)

“…The six Y-C1 bonds involved in the formation of Y-Cl-Y bridges display distances in the range 2.677(1)-2.860(1) Å (2.77 Å on average), and are slightly longer than those observed in dimeric bis[(µ-Cl)Y III (cyclopentadienyl)] complexes (2.66-2.70 Å). [11][12][13] This Y-Cl lengthening can be justified by the presence of a µ-Cl bridge between yttrium atoms and two µ 3 -Cl bridges which involve all three metal centers. The remaining µ-Cl1 and µ-Cl5 chlorides connecting yttrium atoms with lithium display shorter Y-Cl distances of 2.607(2) and 2.627(1) Å, in agreement with those found in the range 2.62-2.65 Å in similar Y-Cl-Li fragments.…”

“…[24] We also noticed some differences between the polymers obtained with the methylsubstituted (7) and phenyl-substituted (11) derivatives. While with the methyl-substituted complex 7, after the usual work-up, a single fraction of highly linear polyethylene was produced (single peak at δ = 27.7 ppm in the 13 C NMR spectrum), with the phenyl-substituted complex 11 the yield was almost twice as high but the solid consisted of two fractions, the first (43 %) of which is similar to the polymer isolated with the catalyst 7 and the second (57 %) of which contains a mixture of oligomers. Apparently this different behavior can be attributed to the influence of the substituent in the ancillary ligand.…”

Homolysis of the Ln–N bond: Synthesis, characterization and catalytic activity of organolanthanide(II) complexes with furfuryl- and tetrahydrofurfuryl-functionalized indenyl ligands

“…It has been found that organolanthanide complexes behaves a diverse chemistry including catalytic transformations of olefins and lactones polymerization [2], hydroamination/cyclization [3], hydrosilylation [4], hydrophosphination [3b,5], and hydroboration [6]. Organolanthanide(II) complexes are one of the family among the organolanthanide complexes, which can effect various reactions including activation of small molecules such as N 2 [7], CO [8], unsaturated hydrocarbons [9], carbonyl [10], as well as polymerization of ethylene [2], styrene [2], acrylonitrile [11], methyl methacrylate and lactones [2,12].…”