Promoter effect of bicarbonate in hydrogenation of cinnamaldehyde catalyzed by a water-soluble Ru(II)-phosphine complex

Autor: Gábor Papp, Imre Szatmári, Ferenc Joó, Ágnes Kathó
Rok vydání: 2018
Předmět:
Zdroj: Inorganica Chimica Acta. 472:302-306
ISSN: 0020-1693
DOI: 10.1016/j.ica.2017.06.061
Popis: The highly selective formation of cinnamalcohol in hydrogenation of trans-cinnamaldehyde with [{RuCl2(mtppms)2}2] + mtppms as catalyst (mtppms = monosulfonated triphenylphosphine) in aqueous solution was substantially accelerated by NaHCO3 (in 20–50 mol% quantities relative to cinnamaldehyde). More than double conversion compared to bicarbonate-free systems was observed at n(NaHCO3)/n(Ru) = 20. Prehydrogenation of the reaction mixture before the addition of cinnamaldehyde resulted in further rate increase (45.3% conversion vs. 13.1% in water). 1H , 13C and 31P NMR studies revealed that formate produced in hydrogenation of bicarbonate facilitated formation of trans-[Ru(H)2(H2O)(mtppms)3], a better catalyst than cis-fac-[Ru(H)2(H2O)(mtppms)3] which is the product of the reaction of [{RuCl2(mtppms)2}2] + mtppms with H2 in the absence of formate (or bicarbonate). Accordingly, NaHCO2 produced even higher rate increase than the same amount of NaHCO3.
Databáze: OpenAIRE