Soluble Catalysts for the Hydrogenation of Olefins

Extremely Active Catalysts for the Hydrogenation of Terminal Alkenes

“…A bicomponent catalyst composed of a titanocene complex and a reducing agent for the hydrogenation of unsaturated hydrocarbons has attracted much attention (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17). Among the reducing agents employed, lithium alkyls, aluminum alkyls, Grignard reagent, lithium aluminum hydride and its derivatives, as well as alkali metals have been widely studied (18)(19)(20)(21)(22)(23).…”

Highly Active Catalysts for the Hydrogenation of Styrene

“…In mono(substituted cyclopentadienyl) titanocene complexes (1, 2, 3, 4, 5, 6), catalytic efficiencies (TO in 2 h) increase with increase of steric hindrance of substituents of titanocene complexes. In bis(substituented cyclopentadienyl) titanocene complexes, catalytic efficiencies (TO in 2 h) firstly increase and then decrease with increase of steric hindrance of substituents of titanocene complexes (7,8,9,10,11,12). This is probably due to two roles of bigger steric hindrance of substituents of titanocene complexes on catalytic efficiencies: one is that bigger steric hindrance of substituents of titanocene complexes can slow dimerization of active titanium species causing increase of catalytic efficiencies, another is that bigger steric hindrance of substituents of titanocene complexes can slow coordination of styrene and active titanium species causing decrease of catalytic efficiencies.…”

“…A bicomponent catalyst composed of a titanocene complex and reducing agent for the hydrogenation of olefins has attracted much attention. The reducing agents include lithium alkyls, aluminum alkyls, Grignard reagent, lithium aluminum hydride, alkali metal and alkali metal hydride [4][5][6][7][8][9][10][11][12]. Among them, use of nanometer-size sodium hydride as cocatalyst for titanocene complexes formed active catalysts for the hydrogenation of olefins.…”

8.17 Homogeneous Catalytic Hydrogenation of CåC and CåC

“…109,110 Nickel-or cobalt-based Ziegler catalysts allow the efficient hydrogenation of aromatic compounds. [111][112][113][114] With these systems, o-xylene gives a mixture of cis-and trans-1,2-dimethylcyclohexane with the former as the major product. Whereas phenol, dimethyl phthalate, and dimethyl terephthalate are reduced in high yield, the presence of a nitro group stops reduction from occurring.…”