86067-58-5Relevant articles and documents
CYCLOADDITIONS CATALYZED BY TITANIUM COMPLEXES
Mach, Karel,Antropiusova, Helena,Petrusova, Lidmila,Hanus, Vladimir,Turecek, Frantisek,Sedmera, Petr
, p. 3295 - 3302 (2007/10/02)
The Ziegler catalyst TiCl4-Et2AlCl and the arenetitanium(II) complex (η6-C6H6)Ti(II)(AlCl4)2 induce cycloaddition reactions of cycloheptatriene with dienes and acetylenes.Addition to 1,3-butadiene affords 7-endo-vinyl-bicyclonona-2,4-diene (main product) and bicyclo-undeca-2,4,8-triene, a product of cycloaddition.Isoprene reacts similarly, yielding mainly 7-endo-isopropenyl-bicylonona-2,4-diene. 2,3-Dimethyl-1,3-butadiene gives 8,9-dimethylbicycloundeca-2,4,8-triene, a product of cycloaddition, while cross-adducts are minor products.The reaction of cycloheptatriene with norbornadiene gives mainly hexacyclo2.7.03.12.06.10.09.13>tetradec-4-ene via cycloaddition followed by intramolecular Diels-Alder reaction.As a by-product, pentacyclo2.7.03.5.04.8>tetradeca-10,12-diene is formed by a mechanism.Addition of cycloheptatriene to phenylacetylene and bis-(trimethylsilyl)acetylene furnishes substituted bicyclonona-2,4,7-trienes.Alkenes, E,E-2,4-hexadiene and 1,3-cyclooctadiene are unreactive.The cycloaddition is made possible by coordination of cycloheptatriene to titanium, which changes the symmetry of the frontier orbitals in the triene.The reactivity of the trienophile is also enhanced by coordination to the catalyst.
Relative Thermodynamic Stabilities of 1,6-Methanoannulene, Dinorcaradiene, and the1,6-Methanoannulene Anion Radical
Stevenson, Gerald R.,Zigler, Steven S.
, p. 895 - 898 (2007/10/02)
The enthalpies of reaction of both the solvated and solid salts of potasssium 1,6-metanoannulene (M10) anion radical were measured with calorimetric techniques.These measurements show that anion radical of M10 has suprising degree of thermodynamic stability.The heat of formation of K+M10-*(s) from gas-phase potassium and gas-phase hydrocarbon (-61.9 kcal/mol) is about 16 kcal/mol more negative than that for the solid potassium salt of the naphthalene anion radical.Combustion experiments were used to show that the open form of M10 is about 5.7 kcal/mol lower in energy than dinorcaradiene.
?6s + ?2s> Cyloadditions Catalysed by the TiCl4-Et2AlCl System
Mach, Karel,Antropiusova, Helena,Sedmera, Petr,Hanus, Vladimir,Turecek, Frantisek
, p. 805 - 806 (2007/10/02)
The catalyst system TiCl4-Et2AlCl induces ?6s + ?2s> cycloadditions of cycloheptatriene to buta-1,3-diene, norbornadiene, and acetylenes.
