- (S,S,S)-Perhydroindolic acid: efficient catalyst for direct asymmetric aldol reaction from aromatic aldehydes
-
Enantioselective addition of ketones to aromatic aldehydes has been achieved with up to 88% enantiomeric excess, using the commercially available (S,S,S)-perhydroindolic acid catalyst.
- Tang, Xiaoping,Liegault, Benoit,Renaud, Jean-Luc,Bruneau, Christian
-
-
Read Online
- Biomass waste-derived recyclable heterogeneous catalyst for aqueous aldol reaction and depolymerization of PET waste
-
In this work, we discuss the valorization of biomass waste-derived orange peel ash (OPA) by exploring its applicability as a heterogeneous catalyst in aqueous aldol reactions and demonstrating its versatility by promoting the methanolysis of poly(ethylene terephthalate) (PET) waste. The catalyst was characterized using Fourier-transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) analysis, X-ray powder diffraction (XRD), X-ray fluorescence (XRF), energy dispersive X-ray (EDX) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and thermal gravimetric analysis (TGA) to decode its chemical composition. The aldol reactions were carried out at ambient temperature in the presence of water as a solvent. PET depolymerization was performed in an autoclave for 1 h using only 6% w/w OPA. The catalyst was recovered and reused in both the reactions for up to four successive cycles with minimal loss in the catalytic activity. The use of OPA as a cost-free, eco-friendly and effective recyclable catalyst enables a greener route for C-C bond formation and PET waste recycling.
- Khiangte, Vanlalngaihawma,Laldinpuii, Z. T.,Lalhmangaihzuala, Samson,Lalmuanpuia, Chhakchhuak,Pachuau, Zodinpuia,Vanlaldinpuia, Khiangte
-
p. 19542 - 19552
(2021/11/09)
-
- Accelerating the optimization of enzyme-catalyzed synthesis conditionsviamachine learning and reactivity descriptors
-
Enzyme-catalyzed synthesis reactions are of crucial importance for a wide range of applications. An accurate and rapid selection of optimal synthesis conditions is crucial and challenging for both human knowledge and computer predictions. In this work, a
- Liang, Jinhu,Liu, Dongchang,Wan, Zhongyu,Wang, Quan-De
-
supporting information
p. 6267 - 6273
(2021/07/28)
-
- Silica Jar-with-Lid as Chemo-Enzymatic Nano-Compartment for Enantioselective Synthesis inside Living Cells
-
Nanodevices, harvesting the power of synthetic catalysts and enzymes to perform enantioselective synthesis inside cell, have never been reported. Here, we synthesized round bottom jar-like silica nanostructures (SiJARs) with a chemo-responsive metal-silic
- Dubbu, Sateesh,Kim, Seonock,Kumar, Amit,Kumari, Nitee,Lee, In Su,Lim, Jongwon
-
supporting information
p. 16337 - 16342
(2021/06/28)
-
- Chiral imidazolium prolinate salts as efficient synzymatic organocatalysts for the asymmetric aldol reaction
-
Chiral imidazolium L-prolinate salts, providing a complex network of supramolecular interaction in a chiral environment, have been studied as synzymatic catalytic systems. They are demonstrated to be green and efficient chiral organocatalysts for direct asymmetric aldol reactions at room temperature. The corresponding aldol products were obtained with moderate to good enantioselectivities. The influence of the presence of chirality in both the imidazolium cation and the prolinate anion on the transfer of chirality from the organocatalyst to the aldol product has been studied. Moreover, interesting match/mismatch situations have been observed regarding configuration of chirality of the two components through the analysis of results for organocatalysts derived from both enantiomers of prolinate (R/S) and the trans/cis isomers for the chiral fragment of the cation. This is associated with differences in the corresponding reaction rates but also to the different tendencies for the formation of aggregates, as evidenced by nonlinear effects studies (NLE). Excellent activities, selectivities, and enantioselectivities could be achieved by an appropriate selection of the structural elements at the cation and anion.
- Altava, Belén,Burguete, Maria Isabel,García-Verdugo, Eduardo,Luis, Santiago V.,Porcar, Raúl
-
supporting information
(2021/07/26)
-
- A pH-Switchable Aqueous Organocatalysis with Amphiphilic Secondary Amine–Porphyrin Hybrids
-
A series of amphiphilic 5-(cyclic-secondary-amine)-10,15,20-tris(4-sulfonatophenyl)porphyrins, designed with the aim of using the amphiphilic porphyrin moiety for the modulation of the aggregation state of the compound by the pH of the medium, have been synthesised, and the relationship between their supramolecular behaviour in acidic aqueous media and their organocatalytic activity in Michael and aldol reactions has been investigated. In particular, we have found that the catalytic activity of the pyrrolidine moiety in an amphiphilic isoindoline–porphyrin hybrid for the aldol reaction of cyclohexanone with 4-nitrobenzaldehyde can be selectively and reversibly switched on and off by adjusting the homogeneity of its solutions through pH variations. The catalysis of the aldol reaction by the secondary amine moiety would otherwise take place regardless of the pH of the medium. We have demonstrated that the aggregation behaviour of these amine–porphyrin hybrids can be also used for the recovery and reutilization of the catalysts.
- Arlegui, Aitor,Crusats, Joaquim,Cuesta, Victor,Moyano, Albert,Torres, Pol
-
-
- Chiral amphiphilic secondary amine-porphyrin hybrids for aqueous organocatalysis
-
Two chiral proline-derived amphiphilic 5-substituted-10,15,20-tris(4-sulfonatophenyl)porphyrins were prepared, and their pH-dependent supramolecular behavior was studied. In neutral aqueous solutions, the free-base form of the hybrids is highly soluble, a
- Arlegui, Aitor,Torres, Pol,Cuesta, Victor,Crusats, Joaquim,Moyano, Albert
-
-
- Surface wettability modification of amine-functionalized polyacrylonitrile fiber to enhance heterogeneous catalytic performance for aldol reaction in water
-
Heterogeneous catalytic aldol reaction has widely focused on tethering multiple functional groups upon support that can act together (for example, acid-base cooperation) to improve reaction rate beyond individual moiety alone. Here, a series of amine-func
- Ma, Ning,Tao, Minli,Zhang, Chenlu,Zhang, Wenqin,Zhu, Hai
-
-
- Enhancing the selectivity of prolinamide organocatalysts using the mechanical bond in [2]rotaxanes
-
The synthesis of a pair of switchable interlocked prolinamides and their use as organocatalysts in three different enamine-activated processes are reported. A diacylaminopyridine moiety was incorporated into the thread for directing [2]rotaxane formation further allowing the association of complementary small molecules. The rotaxane-based systems were tested as organocatalysts in asymmetric enamine-mediated processes, revealing a significantly improved catalytic ability if compared with the non-interlocked thread. The presence of an electron-withdrawing nitro group at the macrocycle helps to achieve high conversions and enantioselectivities. These systems are able to interact with N-hexylthymine as a cofactor to form supramolecular catalysts displaying a divergent catalytic behaviour. The presence or absence of the cofactor controls the chemoselectivity in competitive reactions.
- Calles, Mariá,Puigcerver, Julio,Alonso, Diego A.,Alajarin, Mateo,Martinez-Cuezva, Alberto,Berna, Jose
-
p. 3629 - 3635
(2020/04/20)
-
- Silica gel-mediated self-aldol reactions of highly volatile aldehydes under organic solvent-free conditions without reflux condenser
-
Silica gel-mediated self-aldol reactions were catalyzed by piperidine to give the corresponding α,β-conjugated aldehydes in good yields. The aldol reactions of 4-nitro-, 4-trifluoromethyl-, and 4-chlorobenzaldehydes with acetone afforded the corresponding aldol products. Highly volatile aldehydes and acetone could be employed even without a reflux condenser for these reactions. Silica gel could be recycled five times without any significant decrease of the yields of the products.
- Tanemura, Kiyoshi
-
supporting information
p. 1924 - 1928
(2019/06/24)
-
- Studies on catalytic activity of MIL-53(Al) and structure analogue DUT-5(Al) using bdc- and bpdc-ligands functionalized with L-proline in a solid-solution mixed-linker approach
-
Proline-functionalized MOFs MIL-53(Al) (based on the benzene-1,4-dicarboxylate, bdc linker) and DUT-5(Al) (based on the biphenyl-4,4′-dicarboxylate, bpdc linker) were synthesized using a mixed-linker approach. The proline-functionalized bdc and bpdc ligand was mixed with both the non-functionalized ligand as well as the amino functionalized one. The influence of the length of the linker on the catalytic activity showed a counterintuitive confinement effect and advantageous increase of ee with longer linker and higher porosity, that is a change of ee values from no selectivity in the MIL-53(Al) MOFs up to 16% ee for 27-L-Pro/H2N-DUT-5(Al) and 19% ee for 26-L-Pro/H-DUT-5(Al). The conversion of 4-nitrobenzaldehyde remains over 85% after three catalytic runs for L-proline functionalized MIL-53(Al) MOFs. For the DUT-5(Al) MOFs with L-proline groups this value even increases up to 97%.
- Nie?ing, Sandra,Janiak, Christoph
-
-
- Optimized Cellulose Nanocrystal Organocatalysts Outperform Silica-Supported Analogues: Cooperativity, Selectivity, and Bifunctionality in Acid-Base Aldol Condensation Reactions
-
Cellulose nanocrystals (CNCs) are demonstrated as effective, ordered supports for cooperative acid-base heterogeneous organocatalysis, offering an alternative to typical silica supports. CNC catalyst surface chemistry is optimized through quantitative control of the loadings of carboxylic acids, primary amines, and sulfate half-esters, as characterized by elemental analysis, conductometric titration, and FT-IR spectroscopy. Catalysts are evaluated in the liquid phase aldol condensation of 4-nitrobenzaldehyde or furfural with acetone. Carboxylic acids are effective cooperative acid partners in CNC organocatalysts, and site-specific activity is strongly correlated with the COOH:NH2 ratio. Partial sulfate half-ester removal, high acid/base ratios, and use of unprotected diamines in the catalyst synthesis lead to optimized CNC catalyst function (site-time yield = 1.0 × 10-4 s-1). High selectivities to dehydrated aldol products (>80%) are achieved due to the acid content of the CNC catalysts. CNC catalysts outperform analogous SBA-15-supported aminosilica catalysts in regard to both activity and selectivity. Crystalline surface structures and ordered chemical functionalization in CNCs appear advantageous for precise design and control of bifunctional acid-base cooperative catalysts.
- Ellebracht, Nathan C.,Jones, Christopher W.
-
p. 3266 - 3277
(2019/03/26)
-
- Interfacial Control of Catalytic Activity in the Aldol Condensation: Combining the Effects of Hydrophobic Environments and Water
-
Aminopropyl-functionalized mesoporous silica nanoparticles (AP-MSN) catalyze aldol condensations. The activity of AP-MSN decreases with increasing solvent polarity due to the stabilization of ion pairs formed between acidic silanol groups and the amines, which ultimately decreases the number of catalytically active amine sites. However, the reaction in water is faster than expected on the basis of polarity, because water limits the formation of Schiff bases that are also responsible for blocking active sites. In this work, we combined the action of water with a low-local-polarity environment around the catalytic sites of AP-MSN to maximize active site availability and catalyst performance. We specifically demonstrate how the local polarity of AP-MSN can be controlled by modifying its surface with varying concentrations of hexyl groups and how the dielectric constant of the silica-water interface can be determined using the solvatochromic probe Prodan. The catalytic activities of hexyl-modified AP-MSN in water were inversely proportional to their interfacial dielectric constants and were significantly higher (roughly by a factor of 4) than those of AP-MSN in anhydrous solvents of comparable polarities. Producing low-local-polarity environments in aqueous AP-MSN also enhanced the sensitivity of the aldol reaction to the electronic effects of substituents in the substrate. The enhancement of catalytic activity by low interfacial polarity was also observed in other amine-catalyzed C-C bond forming reactions such as the Henry and vinylogous aldol reactions. Overall, our results demonstrate that the catalytic activity of AP-MSN can be controlled by the synergistic action of water and a low interfacial dielectric constant.
- Singappuli-Arachchige, Dilini,Kobayashi, Takeshi,Wang, Zhuoran,Burkhow, Sadie J.,Smith, Emily A.,Pruski, Marek,Slowing, Igor I.
-
p. 5574 - 5582
(2019/06/18)
-
- Comparison of deep eutectic solvents and solvent-free reaction conditions for aldol production
-
In this work, we investigated the catalytic aldolase activity of the porcine pancreas lipase (PPL) for 4-nitrobenzaldehyde (4-NBA) and acetone in different deep eutectic solvent (DES) compared with bovine serum albumin (BSA)-catalyzed aldol reaction. The PPL catalyzed the aldol addition specifically towards the desired aldol product, especially in hydrophobic DES. In contrast to this result, BSA-catalyzed aldol additions did not exhibit specificity for neither aldol nor olefin formation. For the PPL-catalyzed reactions, the product composition could be directly correlated with the choice of DES, differing in their hydrophobicity. The initial reaction velocity of the aldol addition was higher in the hydrophilic DES ChCl:Gly. However, this DES was limited by the solubility for the 4-NBA substrate. The 4-NBA containing DES exhibited the highest solubility for 4-NBA. However, the fastest reaction with a final yield of 1296.5 mM, which corresponds to 71% yield and 82% conversion after 32 h, was achieved in the co-solvent acetone, making this reaction solvent-less and improving the productivity up to 40.5 mM h?1 compared to reactions performed in DES.
- Milker,P?tzold,Bloh,Holtmann
-
-
- Efficient Direct Synthesis of Aziridine-Containing Chiral Tridentate Ligands by the Iminium-Mediated Self-Ring Opening Reaction of Enantiopure Aziridines and Salicylaldehydes
-
An efficient method for the direct synthesis of aziridine-containing chiral tridentate ligands was developed from enantiopure aziridines and salicylaldehydes. The method achieved the regiospecific cleavage of more substituted C?N bonds of aziridines through an iminium-mediated self-ring opening reaction of aziridines with up to 95% yield and complete inversion of configuration. The (S)-2-alkylaziridine-derived tridentate ligands displayed excellent activity and stereoselectivity in the zinc trifluoromethanesulfonate-catalyzed asymmetric aldol reactions of acetone and aromatic aldehydes. (Figure presented.).
- Chen, Xingpeng,Lin, Chao,Du, Hongguang,Xu, Jiaxi
-
p. 1647 - 1661
(2019/02/27)
-
- Preparation and characterization of magnetic graphene nanocomposite containing Cu(proline)2 as catalyst for asymmetric aldol reactions
-
A new catalyst has been prepared via immobilization of Cu(proline)2 complex onto the surface of magnetic graphene. The fabricated nanocatalyst was characterized by Fourier-transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD) analysis, vibrating-sample magnetometry (VSM), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), inductively coupled plasma (ICP) techniques, and elemental analysis. Its catalytic performance was investigated in the aldol reaction using a mild and ecofriendly procedure. The synthesized nanocomposite, which contains Cu(II) center as Lewis acid, was found to be an efficient catalyst for asymmetric aldol reactions, affording corresponding aldol products in high yield and excellent enantiomeric excess (> 90?%). The examined catalyst was prepared from low-cost, easily available starting materials and can be readily isolated by magnetic decantation for recycling and reuse in consecutive reactions without significant loss of activity.
- Kooti,Kooshki,Nasiri
-
p. 2641 - 2656
(2019/02/14)
-
- Caged Proline in Photoinitiated Organocatalysis
-
Organocatalysis is an emerging field, in which small metal-free organic structures catalyze a diversity of reactions with a remarkable stereoselectivity. The ability to selectively switch on such pathways upon demand has proven to be a valuable tool in biological systems. Light as a trigger provides the ultimate spatial and temporal control of activation. However, there have been limited examples of phototriggered catalytic systems. Herein, we describe the synthesis and application of a caged proline system that can initiate organocatalysis upon irradiation. The caged proline was generated using the highly efficient 4-carboxy-5,7-dinitroindolinyl (CDNI) photocleavable protecting group in a four-step synthesis. Advantages of this system include water solubility, biocompatibility, high quantum yield for catalyst release, and responsiveness to two-photon excitation. We showed the light-triggered catalysis of a crossed aldol reaction, a Mannich reaction, and a self-aldol condensation reaction. We also demonstrated light-initiated catalysis, leading to the formation of a biocide in situ, which resulted in the growth inhibition of E. coli, with as little as 3 min of irradiation. This technique can be broadly applied to other systems, by which the formation of active forms of drugs can be catalytically assembled remotely via two-photon irradiation.
- Guruge, Charitha,Rfaish, Saad Y.,Byrd, Chanel,Yang, Shukun,Starrett, Anthony K.,Guisbert, Eric,Nesnas, Nasri
-
supporting information
p. 5236 - 5244
(2019/05/10)
-
- Chiral gating for size- And shape-selective asymmetric catalysis
-
A poor or mediocre stereoselectivity is a key roadblock for a chiral catalyst to find practical adoptions. We report a facile method to create a tunable chiral space near a chiral catalyst to augment its selectivity. The space was created rationally throu
- Li, Xiaowei,Zhao, Yan
-
supporting information
p. 13749 - 13752
(2019/08/26)
-
- Cascade Reaction by Chemo- and Biocatalytic Approaches to Obtain Chiral Hydroxy Ketones and anti 1,3-Diols
-
A chemo- and biocatalytic cascade approach was applied for the stereoselective synthesis of hydroxy ketones and the corresponding 1,3-diols. A new class of tridentate N,N,O ligands was used with copper(II) complexes for the asymmetric β-borylation of α,β-unsaturated compounds. The complex containing ligand L5 emerged as the best performer, and it gave the organoborane derivatives with good ee values. The corresponding keto–alcohol compounds were then bioreduced by yeasts. The biotransformation set up with Rhodotorula rubra allowed (R)-keto–alcohols and (S,S)-diols to be obtained with up to 99 % ee and up to 99 % de in favor of the anti enantiomers.
- Gandolfi, Raffaella,Facchetti, Giorgio,Christodoulou, Michael S.,Fusè, Marco,Meneghetti, Fiorella,Rimoldi, Isabella
-
p. 393 - 400
(2018/06/04)
-
- Applications of Selenonium Cations as Lewis Acids in Organocatalytic Reactions
-
The use of trisubstituted selenonium salts as organic Lewis acids in electrophilic halogenation and aldol-type reactions has been developed. The substrate scope is broad. The reaction conditions are mild and compatible with various functionalities. This study opens a new avenue for the development of nonmetallic Lewis acid catalysis.
- He, Xinxin,Wang, Xinyan,Tse, Ying-Lung (Steve),Ke, Zhihai,Yeung, Ying-Yeung
-
supporting information
p. 12869 - 12873
(2018/09/14)
-
- L-proline modulated zirconium metal organic frameworks: Simple chiral catalysts for the aldol addition reaction
-
Three L-proline modulated zirconium based MOFs denoted as UiO-66, Zr-NDC (NDC = 2,6-Naphthalenedicarboxylate) and UiO-67 were synthesized, characterized and explored as heterogeneous catalyst in diastereoselective aldol addition reactions between 4-nitrobenzaldehyde and linear/cyclic ketones. Upon L-proline modulation, chirality was introduced into these Zr-MOFs which were consequently explored as chiral catalysts for asymmetric reactions. A systematic study was conducted to look into the effect of the synthesis temperature on the modulation in each Zr-MOF. The modulated UiO-66 material synthesized at 120 °C exhibited full conversion and a good diastereoselectivity whereas the homogeneous L-proline catalyst showed only 61% conversion and a reversed diastereoselectivity. The catalyst exhibited no leaching of the catalytically active species and was reused for at least three additional cycles. The observed high catalytic activity is a result of the electron withdrawing nature of the Zr-node coordinated to L-proline.
- Feng, Xiao,Jena, Himanshu Sekhar,Leus, Karen,Wang, Guangbo,Ouwehand, Judith,Van Der Voort, Pascal
-
-
- Stereoselectivity of Proline/Cyclobutane Amino Acid-Containing Peptide Organocatalysts for Asymmetric Aldol Additions: A Rationale
-
Several α,β,α- or α,?,α-tripeptides, consisting of a central cyclobutane β- or ?-amino acid being flanked by two d- or l-proline residues, have been synthesized and tested as organocatalysts in asymmetric aldol additions. High yields and enantioselectivit
- Illa, Ona,Porcar-Tost, Oriol,Robledillo, Carme,Elvira, Carlos,Nolis, Pau,Reiser, Oliver,Branchadell, Vicen?,Ortu?o, Rosa M.
-
p. 350 - 363
(2018/02/19)
-
- A Mild Procedure for Enone Preparation Catalysed by Bovine Serum Albumin in a Green and Easily Available Medium
-
Abstract: A simple and mild procedure to obtain α,β-unsaturated ketones from acetone and a set of benzaldehydes is described. The approach applies bovine serum albumin (BSA) catalysis and water or ethanol, this mild reaction medium contrasting with the strong reaction conditions of the classic aldol condensation. Except for the assayed nitrobenzaldehydes, high enone yields (88–97%) were attained. In addition to its mildness, further advantages of this procedure are the use of a green catalyst exhibiting an efficient reuse and the use of eco-friendly and cheap solvents. In order to gain a deeper understanding of the involved catalytic mechanism, computational experiments on BSA structural analysis and molecular docking were carried out.
- Ardanaz, Sebastián M.,Velez Rueda, Ana J.,Parisi, Gustavo,Iribarren, Adolfo M.,Iglesias, Luis E.
-
p. 1750 - 1757
(2018/04/24)
-
- Stability, Kinetic, and Mechanistic Investigation of 1,8-Self-Immolative Cinnamyl Ether Spacers for Controlled Release of Phenols and Generation of Resonance and Inductively Stabilized Methides
-
Three cinnamyl ether spacers (non-methyl, α-methyl, and γ-methyl) for caging of phenols have been synthesized and are physiologically stable. When triggered, the γ-methyl spacer releases phenols (pKa 7.8 and 9.8) with a t1/2 a 7.8) with a t1/2 = 27 and 54 min. For the γ-methyl spacer, the results suggest the presence of a resonance and inductively stabilized aza-cinnamyl methide.
- Matikonda, Siddharth S.,Fairhall, Jessica M.,Tyndall, Joel D. A.,Hook, Sarah,Gamble, Allan B.
-
supporting information
p. 528 - 531
(2017/02/10)
-
- An amphiphilic and photoswitchable organocatalyst for the aldol reaction based on a product-imprinted polymer
-
A series of amphiphilic molecularly imprinted polymers (MIP1, MIP2, MIP3, MIP4, MIP5, and MIP6) containing hydrophobic photoresponsive sites and hydrophilic catalytically active sites were fabricated using bifunctional monomers. These polymers were characterized by scanning electron microscopy, N2 adsorption–desorption analysis, Fourier Transform infrared spectroscopy, thermal gravimetric analysis, and ultraviolet–visible spectroscopy. The catalytic activity of the amphiphilic molecularly imprinted polymer was investigated towards the aldol reaction between p-nitroaldehyde and acetone (a molecular enlargement reaction) in a mixed solvent of DMSO and water at room temperature. The polymer catalyst MIP3 performs best, and displayed good conversions with low catalyst loading (5 mol% of L-hydroxyproline with respect to the aldehyde) and photoswitching properties (photo-regulated conversion difference of 20%). Compared with the corresponding non-imprinted polymer, a higher binding capacity, higher conversion, and better photoswitching properties were obtained when the molecularly imprinted polymer was used as the catalyst, illustrating the importance of the specific cavities in the molecularly imprinted polymer.
- Zheng, An-xun,Gong, Cheng-bin,Zhang, Wei-jing,Tang, Qian,Huang, Hai-rong,Chow, Cheuk-fai,Tang, Qian
-
p. 115 - 125
(2017/10/30)
-
- Towards a Series of Chiral Primary Amines Bearing α-Amino Acid and Benzo[d]imidazole Pendants, and Their Application in Asymmetric Aldol Reactions
-
A straightforward reaction path towards chiral primary amines bearing α-amino acid and benzo[d]imidazole pendants has been developed. Six starting essential α-amino acids were converted into the target chiral amines in a four-step synthesis. The prepared
- Mohite, Pravinkumar Hansraj,Drabina, Pavel,Bure?, Filip
-
p. 1613 - 1622
(2017/03/21)
-
- Stereospecific diaza-Cope rearrangement as an efficient tool for the synthesis of DPEDA pyridine analogs and related C2-symmetric organocatalysts
-
A simple and efficient synthesis of enantiomerically pure (1S,2S)-1,2-di(pyridin-2-yl)- and (1R,2R)-1,2-di(pyridin-4-yl)-ethane-1,2-diamines from commercial picolinaldehyde or isonicotinaldehyde and 2,2′-((1S,2S)-1,2-diaminoethane-1,2-diyl)diphenol (HPEN)
- Kucherenko,Kostenko,Gerasimchuk,Zlotin
-
p. 7028 - 7033
(2017/09/01)
-
- POSS-supported C2-symmetric bis-prolinamide and preparation method and application thereof
-
The invention relates to POSS-supported C2-symmetric bis-prolinamide. The structure of POSS-supported C2-symmetric bis-prolinamide is shown in the specification. Chiral prolinamide is supported on a POSS carrier to prepare a novel POSS-supported C2-symmet
- -
-
Paragraph 0016
(2016/11/28)
-
- β- and δ-amino acids (2,3- and 3,4-trans-CHA) as catalysts in Knoevenagel condensation and asymmetric aldol reactions
-
The efficacy of the β- and δ-amino acids (5S,6S)-6-amino-5-hydroxycyclohexa-1,3-dienecarboxylic acid (2,3-trans-CHA) and (3R,4R)-4-amino-3-hydroxycyclohexa-1,5-dienecarboxylic acid (3,4-trans-CHA) as catalysts in Knoevenagel condensation and aldol additio
- Al-Momani, Lo'Ay Ahmed,Lorbach, Volker,Detry, Jean,Geilenkirchen, Petra,Müller, Michael
-
p. 172 - 183
(2018/05/09)
-
- Traceless OH-Directed Wacker Oxidation-Elimination, an Alternative to Wittig Olefination/Aldol Condensation: One-Pot Synthesis of α,β-Unsaturated and Nonconjugated Ketones from Homoallyl Alcohols
-
A new method for one-pot synthesis of β-substituted and β,β-disubstituted α,β-unsaturated methyl ketones from homoallyl alcohols by sequential PdCl2/CrO3-promoted Wacker process followed by an acid-mediated dehydration reaction has been developed. Remarkably, internal homoallyl alcohols delivered regioselectively nonconjugated unsaturated carbonyl compounds under the same protocol. A new starting material-based synthesis of α,β-unsaturated and nonconjugated methyl ketones is demonstrated.
- Bethi, Venkati,Fernandes, Rodney A.
-
p. 8577 - 8584
(2016/09/28)
-
- One-pot bienzymatic cascade combining decarboxylative aldol reaction and kinetic resolution to synthesize chiral β-hydroxy ketone derivatives
-
A bienzymatic one-pot sequential cascade for the synthesis of (S)-β-hydroxy ketones and acylated (R)-β-hydroxy ketone derivatives was successfully developed. An immobilized lipase from Mucor miehei (MML) catalysed promiscuous decarboxylative aldol reaction and a lipase A or B from Candida antarctica (CAL-A or CAL-B) catalysed kinetic resolution of racemic β-hydroxy ketone were combined in this one-pot protocol, reducing the purification step between the two reactions. Twelve chiral β-hydroxy ketones and the same number of corresponding acylated derivatives were obtained with excellent ee values and high yields through this method, and the scaling up experiment also worked without apparent loss of reaction rate and stereoselectivity.
- Xu, Fan,Xu, Jian,Hu, Yujing,Lin, Xianfu,Wu, Qi
-
p. 76829 - 76837
(2016/08/30)
-
- Application of Deep Eutectic Solvents in Promiscuous Lipase-Catalysed Aldol Reactions
-
The application of deep eutectic solvents has been demonstrated for the first time in promiscuous lipase-catalysed aldol reactions. The model reaction between 4-nitrobenzaldehyde and acetone was examined in depth, with excellent compatibility being found between porcine pancreas lipase and choline chloride/glycerol mixtures for the formation of the aldol product in high yields. The system was compatible with a series of aromatic aldehydes and ketones including acetone, cyclopentanone and cyclohexanone. In some cases, the corresponding α,β-unsaturated carbonyl compounds were found as minor products. Control experiments demonstrate that the enzymatic preparation was also responsible for a collateral dehydration reaction once the aldol product is formed. Deep eutectic solvents are used for the first time in promiscuous lipase-catalysed aldol reactions. The reaction between substituted benzaldehydes and aliphatic ketones has excellent compatibility with porcine pancreas lipase (PPL) and choline chloride/glycerol mixtures and gives the aldol product in high yields. PPL was also responsible for a collateral dehydration reaction.
- González-Martínez, Daniel,Gotor, Vicente,Gotor-Fernández, Vicente
-
supporting information
p. 1513 - 1519
(2016/04/05)
-
- Catalyst-free aldol reaction in a water medium
-
Background: With growing interest in developing environmentally friendly reactions and atom-economic processes in recent years, the utilization of water as a solvent has attracted a great deal of attention. This is not only for its low-cost, safe and envi
- Yao, Weirong,Cui, Yanli,Wang, Peipei,Mao, Yangyi
-
p. 293 - 296
(2016/05/24)
-
- Binaphthyl-based chiral bifunctional organocatalysts for water mediated asymmetric List-Lerner-Barbas aldol reactions
-
Novel binaphthyl-based chiral bifunctional organocatalysts were designed, synthesized and successfully applied to the asymmetric List-Lerner-Barbas aldol reaction in the presence of water. These organocatalysts were found to be effective catalysts for the
- Ashokkumar, Veeramanoharan,Chithiraikumar, Chinnadurai,Siva, Ayyanar
-
p. 9021 - 9032
(2016/10/07)
-
- Enzyme from Daucus carota root catalyzed asymmetric cross aldol reaction
-
A novel enzyme was isolated from specific variety of Daucus carota root catalyzed asymmetric cross aldol reaction of aromatic aldehydes with acetone to afford cross aldol products with excellent yield (up to 95%) and enantioselectivity (up to 99%). A plau
- Acharya, Chiranjit,Mandal, Madhumita,Dutta, Trina,Ghosh, Anil Kumar,Jaisankar, Parasuraman
-
p. 4382 - 4385
(2016/09/13)
-
- Novel efficient bifunctional calixarene thiourea organocatalysts: synthesis and application in the direct enantioselective aldol reactions
-
Novel efficient bifunctional calixarene thiourea organocatalysts have been designed as efficient organocatalysts for direct asymmetric aldol reactions between acetone and aromatic aldehydes. The reactions generated the corresponding products in satisfactory isolated yields (up to 96%) and with excellent enantiomeric excesses (up to 99%) in the presence of catalyst (10 mol %).
- Genc, Hayriye Nevin,Sirit, Abdulkadir
-
p. 201 - 207
(2018/10/20)
-
- N-Pyrrolidine-based α/β-peptides incorporating ABOC, a constrained bicyclic β-amino acid, for asymmetric aldol reaction catalysis
-
A series of N-pyrrolidine-based α,β-peptide catalysts incorporating a constrained 2-aminobicyclo[2.2.2]octane carboxylic acid (ABOC) residue were synthesized and evaluated in the asymmetric aldol reaction from acetone and some p-substituted benzaldehydes. Their catalytic properties were shown to be highly dependent on the amino acid sequences and on the absolute configuration of the ABOC residue that played a determinant role. Among the peptides tested, the heterochiral tripeptide H-Pro-(R)-ABOC-Asp-OCH3 13, that adopts a turn conformation in the solid state, proved to be the most efficient catalyst affording β-hydroxy ketones in high yields and good enantioselectivities (up to 87%).
- Milbeo, Pierre,Maurent, Kelly,Moulat, Laure,Lebrun, Aurélien,Didierjean, Claude,Aubert, Emmanuel,Martinez, Jean,Calmès, Monique
-
p. 1706 - 1715
(2016/03/08)
-
- Highly modular dipeptide-like organocatalysts for direct asymmetric aldol reactions in brine
-
A novel series of dipeptide-like organocatalysts derived from proline, amino acids and primary amines have been prepared for direct asymmetric aldol reactions between various aromatic aldehydes and acetone to afford aldol products in good yields (up to 82%) and moderate enantioselectivities (up to 67% ee) with only 1 mol% of catalyst-loading in brine. Under the same conditions, the direct asymmetric aldol reactions of aromatic aldehydes and cyclohexanone give aldol products with high yields (up to 91%) and moderate to good enantioselectivities (up to 88% ee) and excellent diastereoselectivities (up to 99% dr). These organocatalysts are easily synthesized from commercially available materials in multi-gram scale with high modularity in their structural and stereogenic properties.
- Hu, Xiao-Mu,Zhang, Dong-Xu,Zhang, Sheng-Yong,Wang, Ping-An
-
p. 39557 - 39564
(2015/05/20)
-
- Zinc(II) mediated asymmetric aldol condensation catalyzed by chiral aziridine ligands
-
Exploration of chiral aziridine ethers and aziridine alcohols as ligands for the Zn(II) catalyzed enantioselective direct aldol condensations reaction is described. The reaction of acetone with NO2-substituted aromatic aldehydes in the presence
- Pieczonka, Adam M.,Jarzyński, Szymon,Wujkowska, Zuzanna,Les?niak, Stanis?aw,Rachwalski, Micha?
-
p. 6506 - 6507
(2015/11/16)
-
- Reaction-dependent heteroatom modification of acid-base catalytic cooperativity in aminosilica materials
-
The effects of heteroatom substitution on the cooperative catalytic activity of a series of bifunctional acid-base aminosilica catalysts are probed in aldol and nitroaldol condensations. Three M3+ (B, Al, and Ga) and three M4+ (Ti, Zr, and Ce) heteroatoms are incorporated into different samples of SBA-15 silica and then grafted with aminosilanes to produce bifunctional acid-base catalysts. The catalytic activity of each material is measured in the aldol condensation of 4-nitrobenzaldehyde with acetone at 50 °C and the nitroaldol condensation of 4-nitrobenzaldehyde with nitromethane at 40 °C and compared to the catalytic activity of a heteroatom-free aminosilica catalyst. The heteroatom substitutions produce catalysts with larger amounts of strong Lewis acid sites compared to the heteroatom-free aminosilica catalyst. We rationalize these results in the context of the physical (e.g. surface area, pore diameter, particle size) and chemical properties (e.g. total number and strength of acid sites) of each material and the proposed catalytic mechanisms of the two reactions. The increase in the number of strong Lewis acid sites of each heteroatom material decreased its activity in the aldol condensation, though four heteroatom substitutions (B, Al, Ga, and Ti) increased the catalytic activity of the aminosilica catalyst in the nitroaldol condensation. The results suggest that inclusion of a small amount of Lewis acid sites in aminosilica materials can increase the cooperative catalytic activity of the materials in the nitroaldol condensation. The results also suggest that inclusion of Lewis acid sites in aminosilica materials decreases the cooperative catalytic activity of the materials in the aldol condensation.
- Moschetta, Eric G.,Brunelli, Nicholas A.,Jones, Christopher W.
-
p. 429 - 439
(2015/10/05)
-
- Enantiopure Peptide-Functionalized Metal-Organic Frameworks
-
We present herein the first example of metal-organic frameworks postfunctionalized with peptides. Our microwave-assisted postsynthetic modification method yields enantiopure peptides anchored inside MOF cavities. Al-MIL-101-NH2, In-MIL-68-NHsu
- Bonnefoy, Jonathan,Legrand, Alexandre,Quadrelli, Elsje Alessandra,Canivet, Jér?me,Farrusseng, David
-
supporting information
p. 9409 - 9416
(2015/08/06)
-
- PH-Tuned modulation of 1d chain to 3d metal-organic framework: Synthesis, structure and their useful application in the heterogeneous claisen-Schmidt reaction
-
The role of pH in the formation of metal-organic frameworks (MOFs) has been studied on magnesium-based carboxylate framework systems [Mg(Pdc)(H2O)3]n (1) and [Mg(Pdc)(H2O)]n (2) (Pdc=pyridine-2,3-dica
- Sen, Rupam,Saha, Debraj,Koner, Subratanath,Mal, Dasarath,Brando, Paula,Lin, Zhi
-
p. 591 - 598
(2015/03/14)
-
- A photoswitchable organocatalyst based on a catalyst-imprinted polymer containing azobenzene
-
An l-proline-catalyzed aldol reaction was photo-controlled using an l-proline-imprinted polymer containing azobenzene. Upon UV irradiation, azobenzene chromophores underwent trans → cis isomerization, thereby releasing l-proline to catalyze the aldol reac
- Liu, Hua-Dong,Zheng, An-Xun,Gong, Cheng-Bin,Ma, Xue-Bing,Hon-Wah Lam, Michael,Chow, Cheuk-Fai,Tang, Qian
-
p. 62539 - 62542
(2015/08/06)
-
- Benzo[ d ]imidazole and aliphatic α-amino acid derived primary amines in asymmetric aldol reactions
-
Starting from essential α-amino acids, four new benzo[d]imidazole and alkyl-chain-substituted primary amines were synthesized. The reaction sequence involves activation of the Boc-amino acid carboxylic acid, reaction with o-phenylenediamine, and subsequen
- Mohite, Pravinkumar Hansraj,Drabina, Pavel,Bure?, Filip
-
p. 491 - 494
(2014/03/21)
-
- D-Aminoacylase-initiated cascade Aldol condensation/Robinson annulation for synthesis of substituted cyclohex-2-enones from simple aldehydes and acetone
-
As an important building block, developing efficient and green synthesis strategy of cyclohex-2-enones is of great importance. In this present work, a general approach to the mild synthesis of substituted cyclohex-2-enones derivatives starting fro m simple aldehydes and acetone have been achieved via D-aminoacylase-initiated Aldol condensation/Robinson annulation cascade reaction using imidazole as an additive in organic media. The influences of reaction conditions including solvents, enzyme concentration, additives type, molar ratio of enzyme to additive, and substrate scopes were systematically investigated. Furthermore, some experiments were designed to explore the catalytic roles of D-aminoacylase and imidazole in the multistep cascade process, and one possible mechanism was proposed.
- Xiang, Ziwei,Liang, Yiru,Chen, Xiang,Wu, Qi,Lin, Xianfu
-
p. 1929 - 1937
(2014/08/05)
-
- An erbium-based bifuctional heterogeneous catalyst: A cooperative route towards C-C bond formation
-
Heterogeneous bifuctional catalysts are multifunctional synthetic catalysts enabling efficient organic transformations by exploiting two opposite functionalities without mutual destruction. In this paper we report the first Er(III)-based metallorganic heterogeneous catalyst, synthesized by post-calcination MW- Assisted grafting and modification of the natural aminoacid L-cysteine. The natural acid-base distance between sites was maintained to assure the cooperation. The applicability of this new bifunctional heterogeneous catalyst to C-C bond formation and the supposed mechanisms of action are discussed as well.
- Oliverio, Manuela,Costanzo, Paola,Macario, Anastasia,De Luca, Giuseppina,Nardi, Monica,Procopio, Antonio
-
p. 10218 - 10229
(2014/08/05)
-
- Reduced graphene oxide supported piperazine in aminocatalysis
-
Reduced graphene oxide (rGO) has been used as a support for piperazine to provide a heterogeneous bifunctional organocatalyst (rGO-NH) that is able to efficiently promote vintage organic transformations such as Knoevenagel, Michael and aldol reactions. The obtained results suggest a significant role of the support in the course of these reactions. This journal is the Partner Organisations 2014.
- Rodrigo, Eduardo,García Alcubilla, Beatriz,Sainz, Raquel,Fierro, J. L. García,Ferritto, Rafael,Cid, M. Belén
-
supporting information
p. 6270 - 6273
(2014/06/09)
-
- Alkaline earth metal-based metal-organic framework: Hydrothermal synthesis, X-ray structure and heterogeneously catalyzed Claisen-Schmidt reaction
-
Two alkaline earth metal-based carboxylate systems, [Mg(HL)(H 2O)2]n (1) and [Ca(H2L) 2]n (2) (H3L = chelidamic acid) have been hydrothermally synthesized, and characterized by single-crystal X-ray diffraction, IR, elemental analysis, and thermo-gravimetric analysis. Compound 1 has a 2D structure incorporating two water molecules. The dehydrated species, 1a, generated from 1 by removal of the coordinated water, has been characterized by thermo-gravimetric analysis, IR, elemental analysis and variable temperature powder X-ray diffraction. Both 1 and its dehydrated species 1a catalyze the Claisen-Schmidt reaction under heterogeneous conditions, but 1a is a more effective catalyst under environmentally friendly conditions. The catalyst can readily be recovered and reused in successive cycles without detectable loss of activity. Compound 2 has a 3D structure and is thermally stable up to 540 °C, but is inactive catalytically. This journal is the Partner Organisations 2014.
- Saha, Debraj,Maity, Tanmoy,Koner, Subratanath
-
p. 13006 - 13017
(2014/08/18)
-
- Silanol-assisted aldol condensation on aminated silica: Understanding the arrangement of functional groups
-
Free silanol groups are known to promote the activity of aminated silica. In this work the effect of the silanol-to-amine ratio on the aldol condensation of 4-nitrobenzaldehyde and acetone is investigated in a range from 0 to 2.4. Irrespective of the amine density, identical, moderate turnover frequencies are obtained if the silica exclusively has amines on its surface. The turnover frequency increases with increasing silanol-to-amine ratio until an upper limit is reached at a silanol-to-amine ratio of 1.7. At this upper limit the turnover frequency is a factor 5 higher than the turnover frequencies obtained with the monofunctional amine-based catalysts. This increase is ascribed to hydrogen-bridge interactions between the silanols and the carbonyl moiety of the reactants that provoke a more easy interaction between the carbonyl moiety and the amine as required for the aldol condensation. The observation that higher values than one for the silanol-to-amine ratio are required is rationalized by computer simulations. It was found that amine groups were grafted on the silica surface in a clustered manner, originating from positive deviations from ideality in the synthesis mixture, that is, from clustering of the amine precursor in the liquid phase. Copyright
- Lauwaert, Jeroen,De Canck, Els,Esquivel, Dolores,Thybaut, Joris W.,Van Der Voort, Pascal,Marin, Guy B.
-
p. 255 - 264
(2014/01/23)
-
- Interfacial catalysis of aldol reactions by prolinamide surfactants in reverse micelles
-
L-Proline and their derivatives are among the most important class of organic catalysts. Three prolinamide surfactants were designed and synthesized. Although the surfactants carried identical catalytic groups, their headgroups contained different functio
- Arivalagan, Premkumar Rathinam,Zhao, Yan
-
p. 770 - 775
(2015/02/19)
-
- Investigation of proline amides and pyridinium salts as catalyst for direct aldol reactions in water
-
The catalytic potential of chiral proline amides and pyridinium salts in the aldol condensation in water was investigated. The aldol reactions of acetone with various aromatic aldehydes were carried out in water by using proline amide derivatives and pyri
- Ozkan, Asli,Mavis, Murat Emrah,Aydogan, Feray,Yolacan, Cigdem
-
p. 326 - 331
(2014/07/08)
-