1446-84-0Relevant academic research and scientific papers
An easily recoverable and recyclable homogeneous polyester-based Pd catalytic system for the hydrogenation of α,β-unsaturated carbonyl compounds
Bartoli, Mattia,Rosi, Luca,Petrucci, Giorgio,Armelao, Lidia,Oberhauser, Werner,Frediani, Marco,Piccolo, Oreste,Rathod, Vikas Damu,Paganelli, Stefano
, p. 228 - 233 (2015/07/20)
Abstract Homogeneous catalysis is an efficient tool to carry out hydrogenation processes but the major drawback is represented by the separation of the expensive catalyst from the product mixture. In this view we prepared a polyester-based Pd catalytic system that offers the advantages of both homogenous and heterogeneous catalyses: efficacy, selectivity and recyclability. Here its application in the hydrogenation of selected α,β-unsaturated carbonyl compounds is described.
Simple and efficient water soluble thioligands for rhodium and iridium catalyzed biphasic hydrogenation
Di Dio, Sabrina,Marchetti, Mauro,Paganelli, Stefano,Piccolo, Oreste
scheme or table, p. 205 - 210 (2012/02/02)
The activity of catalytic systems derived from the interaction between Rh(CO)2acac and [Ir(COD)Cl]2, respectively, with the water soluble thioligands (L)-Cysteine (1) and (S)-Captopril (2), was tested in the aqueous biphasic hydrogenation of some representative α,β-unsaturated compounds as 2-cyclohexen-1-one (I), trans-cinnamaldehyde (V) and [3-(1,3-benzodioxol-5-yl)-2-methylpropenal] (X), precursor of the fragrance Helional (XI). The precatalyst Rh/Cap was able to hydrogenate cyclohexenone even at low pressure at 60 °C in a neutral medium while Rh/Cy required either higher pressure and temperature or an alkaline medium. The iridium based catalysts, Ir/Cy and Ir/Cap, showed an analogous trend though their activities were lower than those of the related rhodium catalysts. All the catalysts were easily recycled without significant loss of activity. The rhodium catalysts were also used in the hydrogenation of the above aldehydes V and X and their activity was strongly enhanced when ethylene glycol was used as organic solvent or co-solvent.
PROCESS FOR PREPARING HYDROCINNAMIC ALDEHYDES IN ENANTIOPURE OR ENANTIOMERICALLY ENRICHED FORM
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Page/Page column 35-36, (2010/12/17)
A process is described for preparing hydrocinnamic aldehydes in enantiopure or enantiomerically enriched form of Formula I, in which R is isopropyl or tert-butyl and R' is hydrogen, or R and R' when taken together are a methylenedioxolyl group, comprising the following steps: a) reacting the hydrocinnamic aldehyde of Formula I with the alcohol of Formula Il in enantiopure or enantiomerically enriched form to give the crystallized hemiacetal of Formula III, in which R, R' have the same meaning as Formula I and (*) indicates a stereogenic centre in the absence of a solvent or in one or more aprotic solvents or mixtures thereof with apolar solvents; b) recovering the hydrocinnamic aldehyde of Formula I in enantiopure or enantiomerically enriched form from the crystallized hemiacetal of Formula III and the aldehyde of opposite configuration in enantiopure or enantiomerically enriched form from the hemiacetal crystallization mother liquors. The invention also concerns a process for preparing the alcohol of Formula Il to be introduced into step a).
Aqueous biphasic hydrogenations catalyzed by rhodium and iridium complexes modified with human serum albumin
Marchetti, Mauro,Minello, Fabiola,Paganelli, Stefano,Piccolo, Oreste
scheme or table, p. 76 - 80 (2010/10/02)
Water soluble complexes derived from the interaction between Rh(CO)2(acac) and [Ir(COD)Cl]2, respectively, with human serum albumin (HSA), were employed in the aqueous biphasic hydrogenation of α,β-unsaturated compounds as 2-cyclohexen-1-one (I), 2-butenal (V), 3-phenyl-2-propenal (IX) and 3-aryl-2-methyl-2-propenals (XIII and XVII). Both catalytic systems Rh/HSA and Ir/HSA showed to be very active in the hydrogenation of ketone I even at low temperature and hydrogen pressure; in particular, the rhodium based catalyst showed to be very selective affording exclusively cyclohexanone (II). The α,β-unsaturated aldehydes investigated required higher temperature (up to 60 °C) and pressure (5 MPa) to obtain good conversions. In this case Rh/HSA resulted to be more active than Ir based catalyst. In all cases both Rh/HSA and Ir/HSA were easily recycled without significant loss of activity.
