Homogeneous and heterogeneous catalytic asymmetric reactions IV. Hydrogenation of the Ni complexes of cinnamic acid salts over MRNi catalyst

Asymmetric Catalysis at Chiral Metal Surfaces

“…69,337 The only useful catalyst is cinchonamodified Pd; other metals 28,338,339 and modifiers 340,341 are poorly selective. Under optimized conditions, a base (benzylamine) in an almost equivalent amount is added to deprotonate the carboxylic acid and thus weaken the adsorption of the product on Pd.…”

“…The first report on the hydrogenation of α,β-unsaturated carboxylic acids dates back to the early sixties, and continuous improvement mainly by Nitta − resulted in a highly selective transformation of some aryl-substituted acids (Scheme ). , The only useful catalyst is cinchona-modified Pd; other metals ,, and modifiers , are poorly selective. Under optimized conditions, a base (benzylamine) in an almost equivalent amount is added to deprotonate the carboxylic acid and thus weaken the adsorption of the product on Pd .…”

Polymer-supported salen complexes for heterogeneous asymmetric synthesis: Stability and selectivity

“…[1][2][3] The dual ability to preferentially synthesize a particular enantiomer and provide an ease of separation from a reaction makes such catalysts highly practical for industrial application. 4,5 The methods used to generate solid chiral catalysts have included a photoactivation of reactants within a chiral crystalline environment, 6 -8 an inclusion of metals or metal oxides within a host along with a chiral modifier, 9,10 and a ligation or incorporation of a homogeneous catalyst within a support. 1,[11][12][13][14][15] This latter set of catalysts-the so-called heterogenized homogeneous catalystscombines the processing advantages of a heterogeneous catalyst and the potential selectivities of the homogeneous catalysts.…”

Heterogeneous Catalytic Enantioselective Hydrogenation of Activated Ketones

“…Studies on enantioselective catalytic hydrogenation at the University of Szeged started with the investigation of the MRNi catalyst [247][248][249][250]. These studies were also extended to the hydrogenation of steroids [251][252][253][254][255][256][257][258], an important family of compounds successfully researched at the University of Szeged [259][260][261][262].…”