Study of the racemic and enantioselective hydrogenation of acetophenone and 3,4-dimethoxyacetophenone using platinum-based organotin catalysts

Vetere, Virginia; Faraoni, María Belén; Santori, Gerardo Fabián; Podestá, Julio C.; Casella, Mónica Laura; Ferretti, Osmar A.

doi:10.1016/j.cattod.2005.07.079

Cited by 22 publications

(25 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The presence of (-)-menthyl chiral fragments on the surface might be responsible for some kind of geometric interaction with the substrate, which would cause a rate acceleration in the key step of enantiodifferentiation. This phenomenon has already been reported in previous studies for the hydrogenation of 3,4-dimethoxyacetophenone using the same chiral inductor [11] and goes in the same direction as the commonly observed effect in the enantioselective hydrogenation using classical Pt-cinchonidine systems [3,28]. The rate-promoting effect of tin on the enantioselective hydrogenation of 3,4-hexanedione over polymer-stabilized platinum nanoclusters has been investigated by Zhang et al These authors also found that the enantioselectivity could be enhanced by the addition of Sn 2?…”

Section: Catalytic Testssupporting

confidence: 51%

“…Unfortunately, it has not been possible to characterize in detail the chiral catalytic systems, in particular as regards the structure of the organotin phase attached to the platinum surface. However, the results presented below, and other published previously [11,12], show that these systems induce enantioselectivity in the hydrogenation of certain prochiral carbonyl compounds, concluding that at least some (-)-menthyl groups are anchored on the catalyst. Figure 3 shows the results of conversion versus time for the hydrogenation of 3,4-hexanedione.…”

Section: Preparation and Characterization Of The Catalystsmentioning

confidence: 56%

“…The organobimetallic catalysts were prepared by controlled surface reactions, using techniques derived from surface organometallic chemistry on metals (SOMC/M) [10]. These systems have been successfully used by our research group in the enantioselective hydrogenation of other prochiral carbonyl compounds [11,12]. The reaction was carried out following the Podestá and Radivoy technique [13].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Asymmetric Hydrogenation of 3,4-Hexanedione over PtSn Catalysts

et al. 2010

Self Cite

View full text Add to dashboard Cite

In this work, some results of the liquid-phase racemic and enantioselective hydrogenation of 3,4-hexanedione are presented. The catalysts employed were platinum-based, supported on SiO 2 . Monometallic catalysts were modified with organotin precursors either chiral (hexa(-)-menthylditin, Men 3 Sn-SnMen 3 ) or achiral (tetrabutyltin, SnBu 4 ), and they were obtained via surface organometallic chemistry on metals techniques. Asymmetric system was selective to 4-hydroxyhexan-3-one, the enantiomeric excess achieved being 17%.

show abstract

Section: Catalytic Testssupporting

confidence: 51%

Section: Preparation and Characterization Of The Catalystsmentioning

confidence: 56%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Asymmetric Hydrogenation of 3,4-Hexanedione over PtSn Catalysts

et al. 2010

Self Cite

View full text Add to dashboard Cite

show abstract

“…Both supported systems obtained, the organobimetallic (M(SnBu 4-x ) y /SiO 2 ) and the bimetallic (MSn y /SiO 2 ), have shown interesting catalytic properties in terms of activity, selectivity and stability. [24][25][26][27] In order to check on the specificity of the reactions that lead to the bimetallic catalysts obtained by SOMC/M methods, blank tests were performed, consisting of the reaction between SnBu 4 and the SiO 2 support. At temperatures between 298 and 423 K, there was neither evidence of change in the concentration of SnBu 4 with the reaction time (measured by gas chromatography), nor an appreciable amount of tin on the support after several hours of reaction (measured spectrophotometrically).…”

Section: Resultsmentioning

confidence: 99%

Transition metal-based bimetallic catalysts for the chemoselective hydrogenation of furfuraldehyde

Vetere

Merlo

Ruggera

et al. 2010

J. Braz. Chem. Soc.

Self Cite

View full text Add to dashboard Cite

Neste trabalho foi estudada a hidrogenação quimiosseletiva em fase líquida do furfural, empregando-se catalisadores baseados em Pt, Rh e Ni. Sistemas bimetálicos, contendo diferentes quantidades de estanho, foram obtidos por meio de reações de superfície controlada entre um catalisador monometálico e Sn(C 4 H 9 ) 4 . Quando foram utilizados catalisadores monometálicos, os resultados obtidos sugerem uma relação entre as propriedades do metal e da atividade e seletividade. Todos os sistemas permitiram a obtenção do álcool furfurílico com alta seletividade (99, 97 e 76% com catalisadores de Pt, Rh e Ni, respectivamente). A adição de estanho tem efeitos diferentes sobre os três sistemas, tanto em termos de conversão quanto na seletividade. Um resultado interessante foi obtido para os catalisadores baseados em Ni, para os quais a adição de estanho levou a um aumento significativo da seletividade do álcool furfurílico e, dependendo da razão Sn/Ni, também há um aumento na atividade catalítica do sistema.In this work, the liquid-phase chemoselective hydrogenation of furfural was studied, employing Pt, Rh and Ni-based catalysts. Bimetallic systems, containing different amounts of tin, were obtained by means of controlled surface reactions between a monometallic catalyst and Sn(C 4 H 9 ) 4 . The results obtained when monometallic catalysts were employed suggest a relationship between metal properties and the activity and selectivity obtained. All systems allowed obtaining furfuryl alcohol with high selectivity (99, 97 and 76% were achieved with Pt, Rh and Ni catalysts, respectively). The addition of tin has different effects on the three systems, both in terms of conversion and selectivity. An interesting result was obtained for the Ni-based catalysts, for which the addition of tin led to a significant increase in furfuryl alcohol selectivity and, depending on the Sn/Ni ratio, also to an increase in the catalytic activity of the system. Keywords: furfural, furfuryl alcohol, hydrogenation, bimetallic catalysts, PtSn IntroductionThe hydrogenation of furfural is an important reaction in the chemical industry as it is the main way of obtaining furfuryl alcohol.1 This product is widely used in the production of resins, as an intermediate in the manufacture of lysine, vitamin C and lubricants, and to obtain tetrahydrofurfuryl alcohol, among other applications. [2][3][4] Due to the large variety of products that can be obtained from the hydrogenation of furfural, this reaction represents a great challenge from the point of view of its chemoselectivity. As shown in Figure 1, in addition to the products coming from the hydrogenation of the C=O bond and/or the furan ring, there are numerous compounds derived from side reactions (hydrogenolysis of the C=O bond, decarbonylation, hydrogenation and ring opening, condensation reactions, etc.). 3,5 In chemoselective hydrogenation reactions using heterogeneous catalysts, the choice of the active metal is a key factor, since its influence on the resulting activity and/or selectivity is wel...

show abstract

“…The most prominent systems are the cinchona modified Pt [3], and the tartaric acid modified Raney Nickel [4]. The number of practical applications increases continuously and heterogeneous catalytic asymmetric hydrogenations are in the forefront of contemporary catalysis research [5,6]. Following the extensive number of applications with carbonyl compounds, C=C double bond hydrogenation has also attracted significant attention [7].…”

Section: Introductionmentioning

confidence: 99%

Nature of Proline-induced Enantiodifferentiation in Asymmetric Pd Catalyzed Hydrogenations: Is the Catalyst Really Indifferent?

et al. 2008

View full text Add to dashboard Cite

The mode of enantioselection in the proline modified asymmetric hydrogenation of isophorone (3,5,5-trimethyl-2-cyclohexenone) on supported Pd catalysts has been studied. It is shown that several experimental factors, such as modifier structure and chemical nature of the catalyst support, strongly affect the outcome of the hydrogenations. Secondary kinetic resolution was found to be the major reason for obtaining high enantioselectivities on most catalysts. Extensive studies have been carried out to clarify the importance of the interaction of the prolinedihydroisophorone complex with the catalyst. The secondary kinetic resolution of dihydroisophorone was investigated under different conditions. First, racemicdihydroisophorone was studied using several (S)-proline modified supported Pd catalysts, then the individual enantiomers were subjected to a similar reaction on Pd/ BaCO 3 catalyst in the presence of (S)-proline. Our results provide convincing support for the heterogeneous enantioselection model under the current experimental conditions.

show abstract

Study of the racemic and enantioselective hydrogenation of acetophenone and 3,4-dimethoxyacetophenone using platinum-based organotin catalysts

Cited by 22 publications

References 28 publications

Asymmetric Hydrogenation of 3,4-Hexanedione over PtSn Catalysts

Asymmetric Hydrogenation of 3,4-Hexanedione over PtSn Catalysts

Transition metal-based bimetallic catalysts for the chemoselective hydrogenation of furfuraldehyde

Nature of Proline-induced Enantiodifferentiation in Asymmetric Pd Catalyzed Hydrogenations: Is the Catalyst Really Indifferent?

Contact Info

Product

Resources

About