Interactions of the (R) Ru-BINAP Catalytic Complex with an Inorganic Matrix in Stereoselective Hydrogenation of Methylacetoacetate – Kinetic, XPS and DRIFT Studies.

0472520 - ÚCHP 2017 RIV NL eng J - Journal Article
Klusoň, Petr - Krystyník, Pavel - Dytrych, Pavel - Bártek, L.
Interactions of the (R) Ru-BINAP Catalytic Complex with an Inorganic Matrix in Stereoselective Hydrogenation of Methylacetoacetate – Kinetic, XPS and DRIFT Studies.
Reaction Kinetics Mechanism and Catalysis. Roč. 119, č. 2 (2016), s. 393-413. ISSN 1878-5190. E-ISSN 1878-5204
R&D Projects: GA ČR GA15-14228S
Institutional support: RVO:67985858
Keywords : (R)-Ru-BINAP complex * stereoselective hydrogenation * montmorillonite
Subject RIV: CC - Organic Chemistry
Impact factor: 1.264, year: 2016

Stereoselective hydrogenation of methyl acetoacetate to optical isomers of methyl-3-hydroxybutanoate over various forms of supported [RuCl((R)-BINAP)(p-cymene)]Cl is reported. The catalysts were prepared via two alternative methods: direct immobilization, and surface anchorage with heteropolyacids. The kinetic data (rate constants, optical yields, overall selectivity to methyl-3-hydroxybutanoate) were discussed and interpreted with help of XPS and DRIFT to assess bonding surface interactions. In all cases montmorillonite as a model support was employed. It was shown that the stereoselective course was dependent on the mode of [RuCl((R)-BINAP)(p-cymene)]Cl immobilization. The procedure based on the commonly used impregnation did not provide a catalyst with a stable anchorage of the active complex. Strong surface anchorage was found for a catalystproduced with help of H4SiMo12O40 heteropolyacid, but due to structural changes upon the reaction the catalyst performance in the reaction was poor. When H3PW12O40 was employed, the immobilization provided a catalyst with a very good performance. The two-step immobilization via the dimer [RuCl2(p-cymene)](2) instead of the one-step with [RuCl((R)-BINAP)(p-cymene)]Cl yielded a catalyst with the performance parameters comparable to the homogeneous experiments with [RuCl((R)-BINAP)(p-cymene)]Cl dissolved in the reaction mixture. It was due to breaking up the original dimer structure and accomplishing the surface interaction through the adsorbed monomeric units.
Permanent Link: http://hdl.handle.net/11104/0269812