Au0 nanocolloids as recyclable quasihomogeneous metal catalysts in the chemoselective hydrogenation of α,β-unsaturated aldehydes and ketones to allylic alcohols

Mertens, Pascal; Poelman, Hilde; Ye, Xingpu; Vankelecom, Ivo F.J.; Jacobs, Pierre; Vos, Dirk De

doi:10.1016/j.cattod.2007.02.021

Cited by 51 publications

(31 citation statements)

References 36 publications

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“…As in previous work, size-optimized Au 0 nanocolloids were employed in DMF as the reaction medium [18]. Using these optimum metal colloids, the influence of the addition of Lewis-acid metal cations was investigated in the hydrogenation of crotonaldehyde 1a, for which crotyl alcohol 1b is the desired product (Scheme 1).…”

Section: Addition Of Metal Cations To Au 0 Nanocolloidsmentioning

confidence: 99%

“…The Au 0 sols were prepared as described previously [18]. Briefly, 0.2 mmol HAuCl 4 .3H 2 O was added to 8 mL DMF containing 0.133 g polyvinylpyrrolidone (MW = 10.000, PVP-10, Sigma-Aldrich), at a molar ratio PVP monomer/ Au of 6.…”

Section: Preparation Of Au 0 Nanocolloidsmentioning

confidence: 99%

“…We have previously addressed this challenge by preparing polyvinylpyrrolidone (PVP) stabilized sols of Au or other metals (e.g., Ag, Co) via borohydride reduction in amide solvents, e.g., N,N-dimethylformamide (DMF) [17,18]. The cluster size in such metal sols can be varied by changing the PVP/Au ratio in the synthesis.…”

Section: Introductionmentioning

confidence: 99%

“…The cluster size in such metal sols can be varied by changing the PVP/Au ratio in the synthesis. In the hydrogenation of crotonaldehyde in amide solvents, optimized Au 0 nanocolloids with an average cluster diameter of 7 nm were used as quasihomogeneous catalysts, resulting in a selectivity of 75% to crotyl alcohol (1b) at 90% crotonaldehyde (1a) conversion (Scheme 1) [18].…”

Section: Introductionmentioning

confidence: 99%

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Chemoselective C=O Hydrogenation of α,β-unsaturated Carbonyl Compounds over Quasihomogeneous and Heterogeneous Nano-Au0 Catalysts Promoted by Lewis Acidity

Mertens

Wahlen

et al. 2007

Catal Lett

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Lewis-acid promoted Au 0 clusters were used as quasihomogeneous or as heterogeneous metal catalysts for the chemoselective hydrogenation of a,b-unsaturated carbonyl compounds. Addition of Lewis-acid cations like Zn 2+ to amidic dispersions of size-optimized Au 0 nanocolloids led to an enhanced hydrogenation rate and allylic alcohol chemoselectivity in the hydrogenation of e.g., crotonaldehyde (83% selectivity at 92% conversion). Heterogeneous Au 0 catalysts were generated by the quantitative immobilization of the Au 0 nanocolloids on a nanosized ZnO support, followed by partial removal of the polyvinylpyrrolidone stabilizer. This deposition preserved the nanodispersed state of Au 0 , and resulted in a heterogeneous metal catalyst with stable activity and high C=O chemoselectivity in e.g., the hydrogenation of mesityl oxide (66% selectivity at 91% conversion).

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Section: Addition Of Metal Cations To Au 0 Nanocolloidsmentioning

confidence: 99%

Section: Preparation Of Au 0 Nanocolloidsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Chemoselective C=O Hydrogenation of α,β-unsaturated Carbonyl Compounds over Quasihomogeneous and Heterogeneous Nano-Au0 Catalysts Promoted by Lewis Acidity

Mertens

Wahlen

et al. 2007

Catal Lett

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“…Solvent resistant nanofiltration (SRNF) where low-molecular weight compounds (200-1000 g/mol) are separated from organic solvents, is a relatively new but promising area, which offers a wide range of applications in food, pharmaceutical and (petro)chemical industries [33]. Being stable in a wide range of organic solvents, including alcohols, ethyl acetate, toluene and hexane, Matrimid ® membranes have been applied in SRNF, both as asymmetric membranes [20,21,[34][35][36][37] and as porous supports for composite membranes [12,38]. Furthermore, PI membranes can be easily stabilized in more demanding solvents, particularly aprotic solvents, via chemical cross-linking with diamines [39,40].…”

Section: Introductionmentioning

confidence: 99%