- Quantum mechanical predictions of the stereoselectivities of proline-catalyzed asymmetric intermolecular aldol reactions
-
Quantum mechanical calculations were employed to predict the ratio of four stereoisomeric products expected from two complex reactions involving the aldol reactions of cyclohexanone with benzaldehyde or with isobutyraldehyde catalyzed by (S)-proline. Expe
- Bahmanyar,Houk,Martin, Harry J.,List, Benjamin
-
-
Read Online
- Indium trichloride catalysed Mukaiyama aldol reaction in water
-
In the presence of a catalytic amount of indium(III) chloride (InCl3) (20 mol%), aldehydes react smoothly with ketone trimethylsilyl enol ethers in water to afford the corresponding aldol adducts in good yields.
- Loh, Teck-Peng,Pei, Jian,Cao, Guo-Qiang
-
-
Read Online
- Solvent-effects tuning the catalytic reactivity of prolinamides in asymmetric aldol reactions
-
Novel prolinamides were prepared and applied as organocatalysts in the asymmetric aldol reaction. Stable imidazolidinones were formed between prolinamides and aromatic aldehydes in organic solvents. It was found that aqueous conditions can significantly suppress the formation of the unwanted imidazolidinone intermediate and improve the catalytic activity of the prolinamides. As a consequence, high chemical yields (up to 99%) and good diastereoselectivity (up to >20:1 dr) and enantioselectivity (up to 95% ee) were achieved in 2-Me-THF or brine. This strategy could serve as a general solution to enhance the performance of prolinamides as organocatalysts.
- Huang, Xiang-Rong,Liu, Qi,Wang, Jing,Xiao, Jun-An,Yang, Hua
-
-
Read Online
- Indium-trichloride catalyzed Mukaiyama-aldol reaction in water: Solubility, aggregation and internal pressure effect
-
Studies on the effects of water and the binding characteristic of InCl3, in the Mukaiyama-aldol reaction with an in depth mechanistic probe on the probable internal pressure and aggregation effects exerted in this media.
- Loh, Teck-Peng,Pei, Jian,Koh, Kevin Siong-Ve,Cao, Guo-Qiang,Li, Xu-Ran
-
-
Read Online
- Diastereoselective sulfur ylide promoted aldol/epoxidation
-
A mixture of cyclohexanone or 4-methylcyclohexanone and an aromatic aldehyde is treated with dimethylsulfoxonium methylide to effect a tandem aldol/epoxidation reaction. The resulting product contains three or four new stereocenters but only one of the po
- Hansen, Jeffrey A.,Smith, Colin R.,Linder, Ryan J.,Huffman, John C.
-
-
Read Online
- Preparation of Enolates from α-Haloketones with n-BuLi, PhMgBr, or Et2Zn via Halogen-Metal Exchange Reaction
-
Metal-halogen exchange of α-iodoketones was performed upon treatment with n-BuLi, PhMgBr, Et2Zn or Me3Al in ether at 0 deg C to give the corresponding metal enolates which reacted with aldehydes to provide the aldol type products in good yields.
- Aoki, Yoshitaka,Oshima, Koichiro,Utimoto, Kiitiro
-
-
Read Online
- ERYTHRO SELECTIVE ALDOL REACTION OF α-TRICHLOROSTANNYL KETONES
-
The aldol reaction of α-stannyl ketones with aromatic and aliphatic aldehydes is highly (up to 95percent) erythro selective.
- Nakamura, Eiichi,Kuwajima, Isao
-
-
Read Online
- New Crossed Aldol Reaction. Reaction of Enamines with Aldehydes Activated by Lewis Acids
-
Enamines react with aldehydes in the presence of Lewis acids such as BF3*OEt2 to give the corresponding crossed aldol products in good yields.Reaction of dienamines with aldehydes gives the corresponding β, γ-unsaturated α-(1-hydroxyalkyl) carbonyl compou
- Takazawa, Osamu,Kogami, Kunio,Hayashi, Kazuo
-
-
Read Online
- Stereochemistry of aldols: Configuration and conformation of aldols derived from cycloalkanones and aldehydes
-
The structures of cycloalkanone-based threo and erythro aldols were investigated by systematic introduction of stereo-determining factors. The combination of single-crystal X-ray analysis and cryoscopic measurement and solution NMR and IR studies elucidat
- Kitamura,Nakano,Miki,Okada,Noyori
-
-
Read Online
- Lewis acid promoted ene-like reactions of enol ethers with aldehydes
-
Use of organoaluminum reagents induces ene-like reactions of enol silyl ethers with aldehydes, and enols having bulky silyl groups selectively afforded syn adducts.
- Shoda,Nakamura,Tanino,Kuwajima
-
-
Read Online
- Enantiopure cis- and trans-2-(2-Aminocyclohexyl)phenols: Effective Preparation, Solid-State Characterization, and Application in Asymmetric Organocatalysis
-
Effective synthesis of cis- and trans-2-(2-methoxyphenyl)cyclohexylamine as well as their multigram-scale optical resolution by diastereomeric salt formation with dibenzoyl tartaric acid have been described. Assignment of absolute configurations to the enantiomers has been made by X-ray crystallography. Starting from the resolved precursor, diverse aminoalkylphenols (AAPs) having primary, secondary, and tertiary amine group as well as a quaternary ammonium phenol have been prepared as potential bifunctional organocatalysts based on the cyclohexane backbone. We furthermore report herein that AAPs carrying a primary amine and a phenolic hydroxyl group can catalyze the direct aldol reaction with high activity and setereoselectivity, and thus up to 97 % yield, 90:10 syn/anti diastereomeric ratio, and 80 % enantiomeric excess can be achieved.
- Tezeren, Mustafa A.,Ye?il, Tolga A.,Zorlu, Yunus,Tilki, Tahir,Ertürk, Erkan
-
-
Read Online
- A solid-supported organocatalyst for continuous-flow enantioselective aldol reactions
-
Asymmetric aldol reactions catalyzed by a novel polystyrene-immobilized proline derivative occur in short reaction times with excellent diastereo- and enantioselectivity. The catalyst can be recovered by simple filtration and shows very high reusability.
- Ayats, Carles,Henseler, Andrea H.,Pericás, Miquel A.
-
-
Read Online
- Repeated Use of the Catalyst in Ln(OTf)3-Catalyzed Aldol and Allylation Reactions
-
The lanthanoide trifluoromethanesulfonate (lanthanoid triflate)-catalyzed aldol reactions of silyl enol ethers with aldehydes and allylation reactions of tetraallyltin with aldehydes proceeded smoothly in a water-ethanol-toluene system.The reactions proce
- Kobayashi, Shu,Hachiya, Iwao,Yamanoi, Yoshinori
-
-
Read Online
- Acid-base catalyses by dimeric disilicoicosatungstates and divacant γ-Keggin-type silicodecatungstate parent: Reactivity of the polyoxometalate compounds controlled by step-by-step protonation of lacunary W{double bond, long}O sites
-
The catalytic properties of disilicoicosatungstates, [{γ-SiW10O32(H2O)2}2(μ-O)2]4- (2) and [H(γ-SiW10O32)2(μ-O)4]7- (3), and their parent divacant γ-Keggin type silicodecatungstate, [γ-SiW10O34(H2O)2]4- (1), toward C-C bond formation reactions have been investigated. The disilicoicosatungstate 2 with aquo ligands exhibits the acidic nature and catalyzes the Mukaiyama-aldol condensation and carbonyl-ene reaction, while 1 and 3 are rather basic and catalyze the Knoevenagel condensation. Therefore, the acid-base properties of a series of lacunary γ-Keggin silicotungstate derivatives 1-3 are clearly different, and the catalyses of 1-3 depend on the molecular structures while 1-3 are composed of a common [SiW10O32] fragment.
- Yoshida, Akihiro,Hikichi, Shiro,Mizuno, Noritaka
-
-
Read Online
- Reinvestigation of the Diastereoselectivity of Kinetic Aldol Condensation of Cyclohexanone Lithium Enolate with Benzaldehyde
-
Aldol condensation of cyclohexanone lithium enolate with benzaldehyde has been shown to give a considerably higher stereoselectivity at low temperature than that reported previously.
- Hirama, Masahiro,Noda, Takeshi,Takeishi, Shoichi,Ito, Sho
-
-
Read Online
- DIASTEREOSELECTIVE ALDOL CONDENSATIONS OF TIN ENOLATES WITH ALDEHYDES
-
The reaction of tin enolates of cyclohexanone or propiophenone with benzaldehyde at -78 deg C gives predominately the threo aldol diastereomer.
- Shenvi, Sharada,Stille, J. K.
-
-
Read Online
- Environmentally benign diastereoselective synthesis of granatane and tropane aldol derivatives
-
Direct aldol reactions of tropinone and granatanone (pseudopelletierine) with aromatic aldehydes were promoted by the presence of water. The anti-syn-diastereoselectivity depended on the amount of water used or on the possibility of product precipitation
- Nodzewska, Aneta,Bokina, Agnieszka,Romanowska, Katarzyna,Lazny, Ryszard
-
-
Read Online
- Polystyrene-supported hydroxyproline: An insoluble, recyclable organocatalyst for the asymmetric aldol reaction in water
-
4-Hhydroxyproline has been anchored to a polystyrene resin through click chemistry, and the resulting catalyst has been successfully applied to the direct aldol reaction in water. The high hydrophobicity of the resin and the presence of water are key to e
- Font, Daniel,Jimeno, Ciril,Pericas, Miquel A.
-
-
Read Online
- Hydrophobically directed aldol reactions: Polystyrene-supported L-proline as a recyclable catalyst for direct asymmetric aldol reactions in the presence of water
-
A simple synthetic methodology for the preparation of a polystyrene-supported L-proline material is reported, and this material has been used as catalyst in direct asymmetric aldol reactions between several ketones and arylaldehydes to furnish aldol produ
- Gruttadauria, Michelangelo,Giacalone, Francesco,Marculescu, Adriana Mossuto,Lo Meo, Paolo,Riela, Serena,Noto, Renato
-
-
Read Online
- Enantioselective direct aldol reaction "on water" promoted by chiral organic catalysts
-
Figure presented 1,1′-Binaphthyl-2,2′-diamine-based (S)-prolinamides in the presence of stearic acid were able to promote the direct aldol condensation of cyclohexanone and other ketones with different aldehydes in the presence of a massive amount of wate
- Guizzetti, Stefania,Benaglia, Maurizio,Raimondi, Laura,Celentano, Giuseppe
-
-
Read Online
- ON THE STEREOCHEMISRY OF THE ALDOL-ADDITION
-
NOE-experiments and STO-3G calculations suggest that E-enol borates exist in an U-conformation 7a, whereas the Z-enol borates should prefer the extended conformation 8b.These observations have been linked to the stereoselectivity of the aldol addition.The
- Hoffmann, Reinhard W.,Ditrich, Klaus,Froech, Sybille
-
-
Read Online
- Aluminium Triiodide Mediated Reductive Dehalogenation of α-Halocarbonyl Compounds and Trapping of the Aluminium Enolate Intermediate via Aldol Reaction
-
Aluminium triiodide has been conveniently used for reductive dehalogenation and aldol condensation of α-halocarbonyl compounds via aluminium enolate.
- Borah, Harsha N.,Boruah, Romesh C.,Sandhu, Jagir S.
-
-
Read Online
- Chiral lithium amides on solid support: Synthesis and applications in enantioselective deprotonation of cyclic ketones
-
Several chiral amines attached to polymer support (Merrifield resin or a soluble analog) are described. Lithium amides, generated from these amines by treatment with BuLi, react with C(S)-symmetrical ketones to give the corresponding enolates enantioselec
- Majewski, Marek,Ulaczyk, Agnieszka,Wang, Fan
-
-
Read Online
- Water-Promoted Organic Reactions: Aldol Reaction under Neutral Conditions
-
The trimethylsilyl enol ether of cyclohexanone adds to benzaldehyde in aqueous solution at room temperature and atmospheric pressure without a catalyst to give good yields of condensation products with a selectivity that is the reverse in comparison with
- Andre, Lubineau
-
-
Read Online
- Efficient Mukaiyama aldol reaction in water with TiO4 tetrahedra on a hydrophobic mesoporous silica surface
-
A new heterogeneous catalyst, hydrophobic TiO4-deposited mesoporous silica, has been designed for the efficient Mukaiyama-aldol condensation, a water-participating Lewis acid-catalyzed reaction between a hydrophobic carbonyl compound and silyl
- Shintaku, Hiroshi,Nakajima, Kiyotaka,Kitano, Masaaki,Hara, Michikazu
-
-
Read Online
- Highly diastereo- and enantioselective direct aldol reactions promoted by water-compatible organocatalysts bearing central and axial chiral elements
-
Two novel bifunctional primary amine catalysts 1 (RA,S,S) and 2 (RA,R,R), which bear both central and axial chiral elements, have been developed to promote highly diastereoselective and enantioselective aldol reactions of arylaldehyd
- Peng, Fang-Zhi,Shao, Zhi-Hui,Pu, Xue-Wei,Zhang, Hong-Bin
-
-
Read Online
- Combined Use of Diphenyltin Sulfide or Lawesson's Reagent and Silver Perchlorate as Effective Catalyst Systems in Aldol Reaction
-
Catalytic aldol reactions of several aldehydes with trimethylsilyl enol ethers are effectively performed by combined use of diphenyltin sulfide (Ph2Sn=S) and silver perchlorate (AgClO4) or Lawesson's reagent (2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphos
- Mukaiyama, Teruaki,Saito, Katsuyuki,Kitagawa, Hideo,Shimomura, Naoyuki
-
-
Read Online
- A chemo-enzymatic oxidation/aldol sequential process directly converts arylbenzyl alcohols and cyclohexanol into chiral β-hydroxy carbonyls
-
The development of a combination enzyme and organocatalyst for aqueous sequential organic transformation has great significance, in that it is not only environmentally friendly but also overcomes only a single methodological drawback, either in the chemical or biological process. Herein, through the utilization of the bulky steric hindrance of chiral proline derivatives, an integrated laccase and proline as a chemo-enzymatic co-catalyst system is developed. It enables an efficient oxidation/aldol enantioselective sequential reaction to be accomplished, overcoming the mutual deactivation issue. As we present in this study, this one-pot organic transformation, an initial laccase-mediated oxidation of arylbenzyl alcohols and cyclohexanol to form aldehydes and cyclohexanone, followed by a subsequent proline derivative-catalyzed aldol condensation of the in situ generated intermediates, provides various 1,2-diastereoisomeric chiral β-hydroxy ketones with acceptable yields and high enantio-/diastereoselectivities.
- Cheng, Qipeng,Li, Hongyu,Liu, Guohua,Su, Yu,Tan, Chunxia,Wang, Chengyi,Wang, Yu,Xiao, Rui
-
supporting information
p. 7773 - 7779
(2021/10/12)
-
- 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)
-
- Organocatalytic asymmetric aldol reaction using protonated chiral 1,2-diamines
-
Organic-catalyzed stereoselective reactions have gained attention because they avoid the problems associated with metal catalysts, but existing catalysts based on proline have limitations. Therefore, (R,R)-(+)-1,2-diphenylethylenediamine (DPEN) was select
- Shim, Jae Ho,Kim, Min-Joon,Lee, Ji Yeon,Kim, Kyoung Hoon,Ha, Deok-Chan
-
supporting information
(2020/08/14)
-
- Photocontrolled Cobalt Catalysis for Selective Hydroboration of α,β-Unsaturated Ketones
-
Selectivity between 1,2 and 1,4 addition of a nucleophile to an α,β-unsaturated carbonyl compound has classically been modified by the addition of stoichiometric additives to the substrate or reagent to increase their “hard” or “soft” character. Here, we demonstrate a conceptually distinct approach that instead relies on controlling the coordination sphere of a catalyst with visible light. In this way, we bias the reaction down two divergent pathways, giving contrasting products in the catalytic hydroboration of α,β-unsaturated ketones. This includes direct access to previously elusive cyclic enolborates, via 1,4-selective hydroboration, providing a straightforward and stereoselective route to rare syn-aldol products in one-pot. DFT calculations and mechanistic experiments confirm two different mechanisms are operative, underpinning this unusual photocontrolled selectivity switch.
- Beltran, Frédéric,Bergamaschi, Enrico,Funes-Ardoiz, Ignacio,Teskey, Christopher J.
-
supporting information
p. 21176 - 21182
(2020/09/17)
-
- Self-assembled Polydiacetylene Nanoribbons for Semi-heterogeneous and Enantioselective Organocatalysis of Aldol Reactions in Water
-
We report the synthesis, characterization, and supra-molecular assembly of novel diacetylene amphiphilic units bearing a chiral proline-derived head group. In water, these amphiphiles self-assemble into twisted ribbons that are photo-polymerized to afford
- Hoang, Minh-Duc,Kumar, Ramar Arun,Buisson, David A.,Ling, Wai Li,Gravel, Edmond,Doris, Eric
-
p. 1156 - 1160
(2020/01/02)
-
- Palladium-Containing and Metal-Free Supported Dendrons As Catalysts in Multistep Conversion of Oxygenates to Fuels
-
This article reports a three-step process: 1) the hydrogenation of phenol, 2) aldol condensation between the cyclohexanone produced in reaction 1 and an aldehyde, and 3) hydrogenation of the aldol reaction product. This is achieved using palladium contain
- Lou, Yueyun,Shantz, Daniel F.
-
p. 1328 - 1336
(2019/02/07)
-
- 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)
-
- Proline-Glycine Dipeptidic Derivatives of Chiral Phosphoramides as Organocatalysts for the Enantiodivergent Aldol Reaction of Aryl Aldehydes and Isatins with Cyclohexanone in the Presence of Water
-
The synthesis of several novel organocatalysts derived from (R)- and (S)-proline-glycine dipeptides and incorporating a chiral phosphoramide fragment was accomplished. These chiral compounds catalyze the enantioselective aldol addition reaction of cyclohe
- Cruz-Hernández, Carlos,Hernández-González, Perla E.,Juaristi, Eusebio
-
p. 3445 - 3459
(2018/06/08)
-
- Monofunctional primary amine: A new class of organocatalyst for asymmetric Aldol reaction
-
A new class of organocatalysts involving a primary amine as the only functional group is developed for catalytic asymmetric aldol reaction of cyclohexanone/cyclopentanone with various aryl aldehydes in the presence of benzoic acid as an additive at ?10su
- Vanlaldinpuia, Khiangte,Bora, Porag,Bez, Ghanashyam
-
p. 301 - 312
(2017/03/23)
-
- Synthesis, characterization and reactivity of (dithiolato)indium complexes
-
We have synthesized indium complexes incorporating tetradentate dithiolate ligands. The 1:1 reaction of InX3 (X?=?OAc, NO3) and the corresponding dithiol or dithiolate yielded the compounds [(SOOS)In(py)(NO3)] (1), [(SNNS)In(OAc)] (2), [In(μ-SNNS)2(μ-OMe)In][NO3] (3), [(SNNSPr)In(OAc)] (4), [(NNS2)In(OAc)] (5) and [(NNS2)In(NO3)] (6) [H2(SOOS)?=?2,2′-(ethylenedioxy)diethanethiol; H2(SNNS)?=?N,N′-dimethyl-N,N′-bis(2-mercaptoethyl)ethylenediamine; H2(SNNSPr)?=?N,N′-diethyl-N,N′-bis(2-mercaptoethyl)propanediamine; H2(NNS2)?=?N,N-diethyl-N′,N′-bis(2-mercaptoethyl)ethanediamine]. The solid-state structures of 1, 2 and 4–6 are mononuclear and show a tetradentate SOOS/SNNS/NNS2 ligand and a distorted octahedral (1) or trigonal bipyramidal (2, 4–6) coordination geometry at indium. Compound 3 is dinuclear, with the indium centres bridged by a -OMe oxygen atom and a thiolate sulfur atom of chelating tetradentate ligands, respectively. InX3 (X?=?Cl, NO3) were found to be useful Lewis acid catalysts for the aldol reaction of benzaldehyde and 1-(trimethylsiloxy)cyclohexene under ambient conditions, while compounds 1–6 show moderate activity as catalysts for the esterification of stearic acid and transesterification of methyl stearate and glyceryl trioctanoate.
- Anderson, Timothy S.,Briand, Glen G.,Brüning, Ralf,Decken, Andreas,Margeson, Matthew J.,Pickard, Heidi M.,Trevors, Eric E.
-
p. 101 - 108
(2017/07/24)
-
- Temperature-controlled Mukaiyama aldol reaction of cyclododecanone (CDD) with aromatic aldehydes promoted by TMSCl: Via the (TMS)3Si intermediate generated in situ
-
An alternative method with temperature dependency for obtaining direct chemo-, regio- and diastereoselective monobenzylidene and β-hydroxy carbonyl derivatives has been developed. In the present work, an attempt has been made to synthesize a precursor con
- Sathesh, Venkatesan,Sathiyanarayanan, Kulathu I.
-
p. 3833 - 3842
(2016/05/09)
-
- 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)
-
- Multifunctional heterocyclic scaffolds for hybrid Lewis acid/Lewis base catalysis of carbon–carbon bond formation
-
Several new classes of hybrid catalysts have been synthesized by tethering heterocyclic metal (Lewis acid) chelating scaffolds to several different amines capable of facilitating enamine catalysis. Oxazole, thiazole, and imidazole-based chiral precatalyst
- Wiedenhoeft, Dennis,Benoit, Adam R.,Wu, Yibiao,Porter, Jacob D.,Meyle, Elisia,Yeung, Teresa H.W.,Huff, Raechel,Lindeman, Sergey V.,Dockendorff, Chris
-
p. 3905 - 3916
(2016/07/06)
-
- Catalytic composition comprising proline derivative and isothiouronium salt and method of manufacturing the same
-
The present invention relates to a catalyst composition comprising proline derivatives and isothiouronium salts and a preparation method thereof and, more specifically, to a catalyst composition exhibiting improved stereoselectivity by hydrogen bonding of
- -
-
Paragraph 0076; 0097-0100
(2016/11/02)
-
- Pyrrolidine-diaminomethylenemalononitrile organocatalyst for solvent-free asymmetric direct aldol reactions
-
Pyrrolidine-diaminomethylenemalononitrile (pyrrolidine-DMM) organocatalyst has been an efficient reaction medium to promote asymmetric direct aldol reactions to afford the corresponding addition products in high yields with up to 99% ee under solvent-free
- Nakashima, Kosuke,Hirashima, Shin-Ichi,Akutsu, Hiroshi,Koseki, Yuji,Tada, Norihiro,Itoh, Akichika,Miura, Tsuyoshi
-
p. 558 - 561
(2015/02/19)
-
- Enantioselective direct aldol reactions promoted by phosphine oxide aziridinyl phosphonate organocatalysts
-
A series of phosphine oxide based chiral Lewis bases were screened as organocatalysts for silicon tetrachloride mediated direct asymmetric aldol reactions between cyclohexanone and various aromatic aldehydes. One of the phosphine oxide-aziridinyl phosphon
- Dogan, ?zdemir,Tan, Duygu
-
p. 1348 - 1353
(2015/11/25)
-
- Tetrahedral boronates as basic catalysts in the aldol reaction
-
β-Hydroxyketones are versatile building blocks in organic synthesis, which can be conveniently synthesized from ketones and aldehydes by aldol reactions. Unfortunately, these reactions often suffer from dehydration of the initially formed β-hydroxyketones
- Müller, Tobias,Djanashvili, Kristina,Peters, Joop A.,Arends, Isabel W.C.E.,Hanefeld, Ulf
-
p. 587 - 595
(2016/02/12)
-
- Intramolecular hydrogen bonding guides a cationic amphiphilic organocatalyst to highly stereoselective aldol reactions in water
-
A novel amphiphilic guanidine organocatalyst, efficient for asymmetric aldol reactions of ketones in water at neutral pH, is disclosed. The reaction presented a clear substrate dependence depicting a free energy linear correlation with ee. Intramolecular
- Valdivielso, ngel M.,Catot, Alba,Alfonso, Ignacio,Jimeno, Ciril
-
p. 62331 - 62335
(2015/08/06)
-
- The lithiation reactivity and selectivity of differentially branched alkyldiphenylphosphine oxides - A simple and versatile approach to ortho-functionalized arylphosphine oxides
-
Alkyldiphenylphosphine oxides typically undergo α-deprotonation with alkyllithium reagents. Here, the lithiation of differentially branched alkyldiphenylphosphine oxides was investigated and a diverse, but predictable reactivity was found. γ-Branched deri
- Mahamulkar, Shraddha G.,Císa?ová, Ivana,Jahn, Ullrich
-
supporting information
p. 793 - 799
(2015/03/18)
-
- Synthesis of sulphur-modified bifunctional hydrotalcites and study of their surface characteristics by inverse gas chromatography
-
In this study, various sulphur-modified hydrotalcite catalysts were prepared, and the influence of calcination temperature on their acid-base properties was investigated. Structural characterization of the catalysts was studied using X-ray powder diffraction, scanning electron microscopy, N2 physisorption, elemental analysis and Fourier transform infrared spectroscopy. The structural characterization indicated that the layer structure of all catalysts was retained but the specific surface areas were enlarged. Inverse gas chromatography was carried out to quantitatively determine the catalysts' acid-base properties by calculating the thermodynamic parameters, including dispersive surface free energy, adsorption free energy, adsorption enthalpy, and acid-base interaction constants. The results showed that the strength and content of acidic and alkaline sites were enhanced with increasing calcination temperature. Moreover, several typical aldol condensation reactions were selected to study the catalytic activity of the developed catalysts. The results showed that the sulphur-modified hydrotalcite catalysts possess high activity and good regenerability for typical aldol condensation reactions.
- Ren, Xiaoqian,Hu, Xi,Zhang, Feng,Wang, Junge,Liang, Jinhua,Wu, Wenliang,Jiang, Min,Wang, Jun
-
p. 4813 - 4820
(2015/10/05)
-
- Asymmetric aldol reaction catalyzed by a chiral phosphine-silver complex
-
A catalytic asymmetric aldol reaction of alkenyl trihaloacetates or a γ,δ-unsaturated δ-lactone with aldehydes or an α-keto ester was achieved by using a 2,2′-bis(diphenylphosphino)-1,1′- binaphthyl·silver trifluoromethanesulfonate complex as the chiral p
- Yanagisawa, Akira,Miyake, Ryoji,Yoshida, Kazuhiro
-
p. 4248 - 4253
(2014/07/21)
-
- Mukaiyama aldol reactions catalyzed by a trimeric organo aluminum(III) alkoxide
-
Mukaiyama aldol reactions of enol ethers with a variety of aldehydes and ketones are efficiently catalyzed at 0-25 °C by the sterically bulky trimeric organo aluminum(III) alkoxide 1 synthesized via the reaction of 3 equiv of AlMe3 with tripodal tris(2-hydroxy-3-tert-butyl-5-methylphenyl) methane and the elimination of 3 equiv of methane. Comparisons of its catalytic properties with the less sterically hindered analogue 2, the more sterically hindered analogue 3, a monomeric aluminum near-analogue 4, and a dimeric alumatrane 5 revealed that 1 possesses superior activity.
- Kim, So Han,Yoon, Sungwoo,Kim, Youngjo,Verkade, John G.
-
p. 1193 - 1206
(2014/09/30)
-
- Gelatin protein-mediated direct Aldol reaction
-
Gelatin protein was found to catalyze the aldol reaction between cyclohexanone and different aromatic aldehydes under mild reaction conditions. The aldol additions carried out in DMSO at 37 yielded the addition products with moderate diastereoselectivitie
- Kühbeck, Dennis,Bachl, Jürgen,Sch?n, Eva-Maria,Gotor-Fernández, Vicente,Díaz Díaz, David
-
p. 574 - 580
(2014/05/06)
-
- Enantiopure azetidine-2-carboxamides as organocatalysts for direct asymmetric aldol reactions in aqueous and organic media
-
A family of enantiopure azetidine-2-caboxamides was asymmetrically synthesized, and was examined as organocatalyst in direct aldol reactions. A well chosen chiral azetidine-2-caboxamide was found to smoothly catalyze the direct aldol reaction of various benzaldehydes with acetone in brine, and β-hydroxy ketones were produced with enantiomeric excess up to 96%. The reaction of benzaldehydes with cyclic ketones also led to the formation of anti-products in diastereomeric ratio up to 99:1 and enantiomeric excess up to 99%.
- Song, Xixi,Liu, Ai-Xiang,Liu, Shan-Shan,Gao, Wen-Chao,Wang, Min-Can,Chang, Junbiao
-
p. 1464 - 1470
(2014/02/14)
-
- Catalytic microwave-promoted direct aldol condensation using resin-bound secondary amine
-
A series of polystyrene-supported imino group-bearing catalysts were prepared. A highly efficient combination of recyclable catalysts and microwave irradiation was developed as a green protocol for the direct aldol reaction. Notably, microwaves greatly shorten the reaction times to only 20 min and improve the yield significantly. Catalyst loading was reduced as well. Different aromatic aldehydes as aldol donors were subjected to our catalyst system and afforded the corresponding products in satisfactory yields. Additionally, the polymer-supported catalysts could be recovered by simple filtration and were reusable for at least four times without significant loss of reactivity. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the following free supplemental resource(s): Full experimental and spectral details.]
- Liao, Fu Xu,Wang, Yu Guang,Zhu, Qing
-
supporting information
p. 161 - 169
(2013/12/04)
-
- Gallium(III) triflate catalyzed diastereoselective mukaiyama aldol reaction by using low catalyst loadings
-
A mild method for the diastereoselective Mukaiyama aldol reaction is reported. By using a low loading of the gallium(III) triflate catalyst (down to 0.01 mol-%), the transformation proceeds efficiently to afford the corresponding β-hydroxy ketones in yields up to 92a€‰%. To the best of our knowledge, this is the first report of a metal triflate acting as a safe, bench-stable, and slow-releasing source of triflic acid for the Mukaiyama aldol reaction. A diastereoselective Mukaiyama aldol reaction was performed under mild conditions with a low loading of the gallium(III) triflate catalyst (down to 0.01 mol-%). The transformation proceeded efficiently to afford the corresponding β-hydroxy ketones in yields up to 92a€‰%. Copyright
- Plancq, Baptiste,Justafort, Lyse Carole,Lafantaisie, Mathieu,Ollevier, Thierry
-
supporting information
p. 6525 - 6529
(2013/11/06)
-
- Study of asymmetric aldol and Mannich reactions catalyzed by proline-thiourea host-guest complexes in nonpolar solvents
-
A proline-thiourea host-guest complex has been described as a good catalyst for asymmetric reactions such as aldol and Mannich reactions. High stereoselectivities were obtained under optimal conditions. Thiourea was observed to have an important effect on the reactivity and selectivity, even in an unconventional nonpolar reaction medium and without the need to utilize low temperatures. This proline-thiourea host-guest system has the ability to participate in a hydrogen bonding network.
- Demir, Ayhan Sitki,Basceken, Sinan
-
p. 515 - 525
(2013/06/26)
-
- Pyrrolidine catalyzed diastereoselective direct aldol reaction in water: A green approach
-
The pyrrolidine catalyzed direct diastereoselective aldol reaction of different cyclic ketones and aromatic aldehydes has been performed in water. The aldol products are formed in high yield (up to 91%) and diastereoselectivity (up to >99:1 (anti:syn)) in
- Singh, Sarbjit,Chimni, Swapandeep Singh
-
p. 1202 - 1209
(2013/10/08)
-
- Novel sulfonylpolystyrene-supported prolinamides as catalysts for enantioselective aldol reaction in water
-
Five novel prolinamides derived from 1,n-diamines supported on commercially available sulfonylpolystyrene have been synthesized and successfully applied in diastereo- and enantioselective aldol reaction in water or, in one case, neat conditions. Excellent
- Pedrosa, Rafael,Andrés, José M.,Gamarra, Ana,Manzano, Rubén,Pérez-López, César
-
p. 10811 - 10819
(2014/01/06)
-
- Dried chitosan-gels as organocatalysts for the production of biomass-derived platform chemicals
-
Aldol condensations between sugar-derived dehydrated aldehydes (e.g. furfural) and acetone have been proposed as a route to provide useful biomass-derived chemicals. In the quest of sustainable catalytic ways for such aldol condensations, this paper assesses the use of dried chitosan-gels as naturally-immobilized, readily available and non-hazardous amino-based organocatalysts. At room temperature chitosan dried gels are not suitable catalysts for the desired reaction. However, at higher temperatures (>90 °C) reaction proceeds efficiently either in solvent-free systems (with addition of catalytic amounts of water) or in water. The set-up of closed reactor set-ups (thermoshakers or microwave reactions) proved highly beneficial for the reaction outcome. Furthermore, chitosan dried gels were successfully re-used for a number of cycles. An efficient catalyst drying method (either lyophilization or scCO2 drying) was crucial to achieve virtually full conversions in 4 h. After pertinent further process optimization, dried chitosan-gels may become very useful catalysts for their use in biomass-based reactions in biorefineries.
- Kayser, Henning,Müller, Christoph R.,García-González, Carlos A.,Smirnova, Irina,Leitner, Walter,Domínguez De María, Pablo
-
p. 180 - 186
(2013/02/23)
-
- Organocatalysis with cysteine derivatives: Recoverable and cheap chiral catalyst for direct aldol reactions
-
Highly enantioselective, recoverable and cheap cysteine derivatives have been developed with improved solubility properties in common, nonpolar organic solvents. The reactions were catalyzed using 5 mol% 1e, and the aldol products could be obtained with up to 99:1 syn/anti ratio and >99% ee. The catalyst could be easily recovered and reused, with only a slight decrease of enantioselectivity observed for five cycles. Catalyst 1e can be efficiently used in large-scale reactions with enantioselectivity being maintained at the same level, which offers great possibility for application in industry. Springer Science+Business Media B.V. 2011.
- Li, Shi,Fu, Xiangkai,Wu, Chuanlong
-
scheme or table
p. 195 - 205
(2012/05/20)
-
- Study of the lanthanide-catalyzed, aqueous, asymmetric Mukaiyama aldol reaction
-
The development of efficient methods for the asymmetric Mukaiyama aldol reaction in aqueous solution has received great attention. We have developed a new series of chiral lanthanide-containing complexes that produce Mukaiyama aldol products with outstanding enantioselectivities. In this paper, we describe an optimized ligand synthesis, trends in stereoselectivity that result from changing lanthanide ions, and an exploration of substrate scope that includes aromatic and aliphatic aldehydes and silyl enol ethers derived from aromatic and aliphatic ketones.
- Mei, Yujiang,Averill, Derek J.,Allen, Matthew J.
-
scheme or table
p. 5624 - 5632
(2012/09/05)
-
- Simple and inexpensive threonine-based organocatalysts as highly active and recoverable catalysts for large-scale asymmetric direct stoichiometric aldol reactions on water
-
Nine O-acylated threonines were screened as catalysts at loadings of 0.5-5 mol % for the direct asymmetric stoichiometric aldol reaction on water by using variable amounts of water. These threonine-based organocatalyst were simple, inexpensive, highly act
- Wu, Chuanlong,Long, Xiaoqin,Li, Shi,Fu, Xiangkai
-
experimental part
p. 315 - 328
(2012/07/14)
-
- Copolymer-supported heterogeneous organocatalyst for asymmetric aldol addition in aqueous medium
-
In the current study, a convenient and simple way is presented to synthesize a novel type of supported heterogeneous organocatalyst in 21-81% yield by the copolymerization of 9-amino-9-deoxy-epi-cinchonine organocatalyst with acrylonitrile using AIBN as r
- Zhou, Jinqing,Wan, Jinwei,Ma, Xuebing,Wang, Wei
-
experimental part
p. 4179 - 4185
(2012/07/14)
-
- Preparation and confinement effect of a heterogeneous 9-amino-9-deoxy-epi- cinchonidine organocatalyst for asymmetric aldol addition in aqueous medium
-
A series of novel porous zirconium phosphonate-supported 9-amino-9-deoxy-epi-cinchonidines of general formulae Zr(OH) 4-2x(O3PR)x·nH2O and Zr(HPO4)2-x(O3PR)x·nH 2
- Wang, Wei,Ma, Xuebing,Wan, Jingwei,Cao, Jun,Tang, Qian
-
experimental part
p. 5715 - 5726
(2012/05/20)
-
- Construction of quaternary carbon centers by a base-catalyzed enantioselective aldol reaction and related reactions of trimethoxysilyl enol ethers
-
The aldol reactions of trimethoxysilyl enol ethers catalyzed by lithium binaphtholate were found to be powerful tools for the construction of quaternary asymmetric carbon centers. The stereoselectivities were greatly affected by the presence of water. Trimethoxysilyl enol ether derived from a cyclic ketone, such as cyclohexanone, was used as a substrate to obtain the anti-adduct preferentially under anhydrous conditions; by contrast, the syn-adduct was preferentially obtained under aqueous conditions with high stereoselectivity. The aldol-Tishchenko reaction of a trimethoxysilyl enol ether derived from acyclic ketones proceeded to give monoacyl 1,3-diol derivatives in high enantioselectivities.
- Ichibakase, Tomonori,Kaneko, Tetsuya,Orito, Yuya,Kotani, Shunsuke,Nakajima, Makoto
-
experimental part
p. 4210 - 4224
(2012/07/14)
-
- Design, synthesis and use of novel 3,3-disubstituted 2,2-bipyridine-based chiral ligands: Asymmetric catalysis in direct aldol reactions
-
A wide range of chiral ligands based on the 2,2-bipyridine scaffold were designed and synthesized. In complexation with metal Lewis acids, the reactivity and stereoselectivity of the prepared chiral ligands were examined in asymmetric catalytic direct ald
- Zhao, Hong-Wu,Li, Hai-Long,Yue, Yuan-Yuan,Qin, Xiao,Sheng, Zhi-Hui,Cui, Jin,Su, Shi,Song, Xiu-Qing,Yan, Hong,Zhong, Ru-Gang
-
supporting information; experimental part
p. 1990 - 1994
(2012/09/25)
-
- TBD/Al2O3: A novel catalytic system for dynamic intermolecular aldol reactions that exhibit complex system behaviour
-
The heterogeneous system TBD/Al2O3 is an efficient catalyst for the intermolecular aldol reaction between ketones and aromatic aldehydes. This system operates with low catalysts loading (10%), in water or organic solvents, and with s
- Martinez-Castaneda, Angel,Rodriguez-Solla, Humberto,Concellon, Carmen,Del Amo, Vicente
-
experimental part
p. 1976 - 1981
(2012/04/23)
-
- Simple ionic liquid supported C2-symmetric bisprolinamides as recoverable organocatalysts for the asymmetric aldol reaction in the presence of water
-
C2-Symmetric (S)-prolinamides modified with ionic groups and bearing achiral diamine units were synthesized. Their potency as reusable organocatalysts for asymmetric aldol reactions of cycloalkanones or methyl ketones with aromatic (heteroaroma
- Kochetkov, Sergei V.,Kucherenko, Alexandr S.,Kryshtal, Galina V.,Zhdankina, Galina M.,Zlotin, Sergei G.
-
supporting information
p. 7129 - 7134
(2013/02/22)
-
- Barium carboxylate metal-organic framework - Synthesis, x-ray crystal structure, photoluminescence and catalytic study
-
A new 3D alkaline earth metal-organic framework (MOF), [Ba(Hdcp)H 2O]n (1) (H3dcp = 3,5-pyrazoledicarboxylic acid), has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction ana
- Maity, Tanmoy,Saha, Debraj,Das, Soma,Koner, Subratanath
-
p. 4914 - 4920
(2013/01/15)
-
- Heterogeneous catalysis over a barium carboxylate framework compound: Synthesis, X-ray crystal structure and aldol condensation reaction
-
A new three-dimensional alkaline-earth metal-organic framework (MOF) compound, [Ba(pdc)]n (1) (H2pdc = pyridine-2,5- dicarboxylate), has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffracti
- Saha, Debraj,Maity, Tanmoy,Sen, Rupam,Koner, Subratanath
-
experimental part
p. 63 - 70
(2012/09/07)
-
- Porous magnesium carboxylate framework: Synthesis, X-ray crystal structure, gas adsorption property and heterogeneous catalytic aldol condensation reaction
-
A new three-dimensional alkaline-earth metal-organic framework (MOF) compound, [Mg(Pdc)(H2O)]n (1) (H2Pdc = pyridine-2,5-dicarboxylic acid), has been synthesized and structurally characterized by single crystal X-ray diffr
- Saha, Debraj,Sen, Rupam,Maity, Tanmoy,Koner, Subratanath
-
experimental part
p. 7399 - 7408
(2012/07/31)
-
- The enzymatic asymmetric aldol reaction using acidic protease from Aspergillus usamii
-
AUAP (acidic protease from Aspergillus usamii) could catalyze the direct aldol reactions between aromatic aldehydes and cyclic ketones in acetonitrile (MeCN) in the presence of water. The enantioselectivities of up to 88% ee and diastereoselectivities of
- Xie, Bang-Hua,Li, Wei,Liu, Yan,Li, Hai-Hong,Guan, Zhi,He, Yan-Hong
-
supporting information; experimental part
p. 3160 - 3164
(2012/06/01)
-
- Chiral picolylamines for Michael and aldol reactions: Probing substrate boundaries
-
Here we report on inroads concerning increased substrate breadth via the picolylamine organocatalyst template, a vicinal chiral diamine based on a pyridine-primary amine motif. The addition of cyclohexanone to β-nitrostyrene has many catalyst solutions, b
- Nugent, Thomas C.,Bibi, Ahtaram,Sadiq, Abdul,Shoaib, Mohammad,Umar, M. Naveed,Tehrani, Foad N.
-
supporting information
p. 9287 - 9294,8
(2012/12/12)
-
- Chiral picolylamines for Michael and aldol reactions: Probing substrate boundaries
-
Here we report on inroads concerning increased substrate breadth via the picolylamine organocatalyst template, a vicinal chiral diamine based on a pyridine-primary amine motif. The addition of cyclohexanone to β-nitrostyrene has many catalyst solutions, b
- Nugent, Thomas C.,Bibi, Ahtaram,Sadiq, Abdul,Shoaib, Mohammad,Umar, M. Naveed,Tehrani, Foad N.
-
supporting information
p. 9287 - 9294
(2013/01/15)
-