Fullerene–proline hybrids: Synthesis, characterization and organocatalytic properties in aldol reactions

Chronopoulos, Demetrios D.; Tsakos, Michail; Karousis, Nikolaos; Kokotos, Christoforos G.; Tagmatarchis, Nikos

doi:10.1016/j.matlet.2014.09.031

Cited by 19 publications

(18 citation statements)

References 31 publications

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“…In 2014 the multistep synthesis of two L‐proline‐C 60 conjugates ( 10 and 11 ) has been reported, one of them having the proline in close proximity and the other far away to the fullerene cage (Scheme ) . These two molecules have been tested as organocatalysts in the asymmetric aldol reaction between ketones and aromatic aldehydes in 10–50 mol % loadings in different solvents.…”

Section: Fullerene‐based Catalystsmentioning

confidence: 99%

Modified Nanocarbons for Catalysis

2018

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Nanocarbons represent useful scaffolds in the preparation of last generation nanostructured catalysts, and their chemical functionalization through covalent or non‐covalent modification is becoming an important tool for introducing well‐distributed anchoring points and, in the meantime, could be the first step toward the assembling of hybrid nanostructured materials with a hierarchical order. In this Review are reported synthesis and catalytic applications of chemically modified nanocarbons such as fullerene, carbon nanotubes, graphene, nanohorns and nanodiamonds in organocatalytic and metal‐based (metal nanoparticles, organometallic complexes) reactions, covering major chemical reactions encompassing, the oxidation of alcohols, aldehydes, olefins, and silanes, hydrogenation reactions of aldehydes, ketones, and alkenes, dehydrogenative coupling of silanes, C−C coupling reactions, epoxidation of alkenes, CO2 fixation into cyclic carbonates, and asymmetric reactions, among others.

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Section: Fullerene‐based Catalystsmentioning

confidence: 99%

Modified Nanocarbons for Catalysis

2018

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“…In order to tackle this problem, a variety of proline derivatives containing bioisosteric groups like sulfonamides [8][9][10] and tetrazoles [11] as well as prolinamides [12,13] and substituted diaryl prolinols [14] have been synthesized and frequently employed in organocatalytic transformations [15]. On top of the aforementioned points, we recently reported that fullerene C 60 carrying a covalently attached proline unit efficiently catalyzes the typical asymmetric aldol reaction between acetone and 4-nitrobenzaldehyde, both in DMSO and water [16].…”

Section: Introductionmentioning

confidence: 99%

Conjugating proline derivatives onto multi-walled carbon nanotubes: Preparation, characterization and catalytic activity in water

et al. 2015

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“…The recently introduced, somehow complementary fullerenes excel in anion‐ π catalysis because of their high polarizability and localized π holes on their surface . Anion‐ π catalysis on fullerenes is particularly attractive because the use of fullerenes in catalysis on the one hand and anion‐ π interactions on fullerenes on the other hand are both underrecognized general topics that deserve scientific attention. In fullerene anion‐ π catalyst 9 , the preorganization from the chiral cyclohexyldiamine turn was used as in NDI catalysts 4 – 6 to position a tertiary amine base close to the active fullerene surface .…”

Section: Resultsmentioning

confidence: 99%

Anion‐π Catalysis: Focus on Nonadjacent Stereocenters

Zhang

Liu

López‐Andarias

et al. 2018

Helvetica Chimica Acta

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In Memory of Gilbert StorkAnion-p interactions have been recently introduced to catalysis with the idea to stabilize anionic intermediates on p-acidic surfaces. Realized examples include enolate, enamine and iminium chemistry, domino processes and DielsAlder reactions. Moving on from the formation of contiguous stereogenic centers on p-acidic surfaces, herein we report the first asymmetric anion-p catalysis of cascade reactions that afford nonadjacent stereocenters. Conjugate addition-protonation of achiral disubstituted enolate donors to 2-chloroacrylonitrile generates 1,3-nonadjacent stereocenters with moderate enantioselectivity and diastereoselectivity. The explored catalysts operate with complementary naphthalenediimide and fullerene surfaces with highly positive quadrupole moments and high polarizability, respectively, and proximal amine bases. We find that anion-p catalysts can increase the diastereoselectivity of the reaction beyond the maximal 1:4.0 dr with conventional catalysts to maximal 5.3:1 dr on the large fullerene surfaces. The enantioselectivity of anion-p catalysts, best on the confined naphthalenediimide surfaces with strong quadrupole moment, exceed the performance of conventional catalysts except for comparable results with a new, most compact, surprisingly powerful bifunctional control catalyst. Simultaneously increased rates and stereoselectivities compared to control catalysts without p-acidic surface support that contributions of anion-p interactions to the catalytic cascade process are significant.

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Fullerene–proline hybrids: Synthesis, characterization and organocatalytic properties in aldol reactions

Cited by 19 publications

References 31 publications

Modified Nanocarbons for Catalysis

Modified Nanocarbons for Catalysis

Conjugating proline derivatives onto multi-walled carbon nanotubes: Preparation, characterization and catalytic activity in water

Anion‐π Catalysis: Focus on Nonadjacent Stereocenters

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