Organochromium π-complexes—VIII. Reactions of the (η5-Me5C5)Cr-system with 1,3-dienes and alkynes

Cyclopentadienylmolybdenum(II) and -(III) Complexes Containing Diene and Allyl Ligands. 2. Comparative Reactivity of the Isomeric Complexes CpMo(η-C3H5)(η-C4H6) with Either supine or prone Allyl and Either s-cis (Supine) or s-trans Butadiene Ligands toward Protons

“…The formation of compound 8 involves coupling of two s-trans butadiene ligands. A similar process has been previously described for the reaction of butadiene with Ni(COD) 2 , [Cp 2 V] - , CpCr(η 3 -C 3 H 5 ) 2 , and Cp*Cr(η 3 -C 3 H 5 ) 2 5 …”

From Hein to Hexene: Recent Advances in the Chemistry of Organochromium π-Complexes

“…In the absence of a P-donor ligand, 3 reacts with 1,3-butadiene to give a dinuclear species ( 8 ) in which two butadiene molecules have dimerized and bridge the metal atoms in an η 3 ,η 3 -manner (Scheme ). The mechanism for the formation of 8 suggested in the scheme is supported by the isolation of mononuclear compounds corresponding to 6 and 7 from the reaction of 1,3-butadiene with Cp * (η 3 -C 3 H 5 ) 2 Cr (Cp * ≡η 5 -C 5 Me 5 ) while the product of the analogous reaction with trans -piperylene has been shown by X-ray diffraction to have the structure shown in Figure in which two piperylene molecules have coupled at the metal atom to give an η 3 ,η 3 -Me 2 C 8 H 8 fragment . The observed head−tail coupling of two piperylene molecules is unusual: head−head coupling has been observed at nickel and tail−tail coupling at zirconium …”

“…The observed head−tail coupling of two piperylene molecules is unusual: head−head coupling has been observed at nickel and tail−tail coupling at zirconium 4 Molecular structure of Cp*(η 3 ,η 3 -1,5-Me 2 C 8 H 8 )Cr …”

“…Bond distances (Å) and angles (deg): Cr−D(Cp*), 1.916(2); Cr−C(allyl), 2.134(3)−2.187(3); C−C(allyl), 1.383(5)−1.403(5); C−C(Cp*), 1.404(4)−1.411(3); C17−C18−C19, 122.0(3); C12−C13−C14, 123.5(3). Reprinted with permission from ref . Copyright 1993 Elsevier Science.

5 Molecular structure of Cp*(η 1 ,η 2 ,η 1 -1,2-Et 2 C 10 H 12 )Cr ( 10 , R = Et) .

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“…Reprinted with permission from ref . Copyright 1993 Elsevier Science.

5 Molecular structure of Cp*(η 1 ,η 2 ,η 1 -1,2-Et 2 C 10 H 12 )Cr ( 10 , R = Et) . Bond distances (Å) and angles (deg): Cr−C7, 2.341(4); Cr−C9, 2.064(5); Cr−D(Cp*), 1.926(6); C7−C8, 1.508(6); C8−C9, 1.542(7); C7−C7*, 1.364(6); C−C(Cp*), 1.383(6)−1.402(5), C7−C8−C9, 106.6(4).

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