42052-56-2Relevant articles and documents
Biomass waste-derived recyclable heterogeneous catalyst for aqueous aldol reaction and depolymerization of PET waste
Khiangte, Vanlalngaihawma,Laldinpuii, Z. T.,Lalhmangaihzuala, Samson,Lalmuanpuia, Chhakchhuak,Pachuau, Zodinpuia,Vanlaldinpuia, Khiangte
, p. 19542 - 19552 (2021/11/09)
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.
A chemo-enzymatic oxidation/aldol sequential process directly converts arylbenzyl alcohols and cyclohexanol into chiral β-hydroxy carbonyls
Cheng, Qipeng,Li, Hongyu,Liu, Guohua,Su, Yu,Tan, Chunxia,Wang, Chengyi,Wang, Yu,Xiao, Rui
supporting information, p. 7773 - 7779 (2021/10/12)
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.
Self-assembled Polydiacetylene Nanoribbons for Semi-heterogeneous and Enantioselective Organocatalysis of Aldol Reactions in Water
Hoang, Minh-Duc,Kumar, Ramar Arun,Buisson, David A.,Ling, Wai Li,Gravel, Edmond,Doris, Eric
, p. 1156 - 1160 (2020/01/02)
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
Organocatalytic asymmetric aldol reaction using protonated chiral 1,2-diamines
Shim, Jae Ho,Kim, Min-Joon,Lee, Ji Yeon,Kim, Kyoung Hoon,Ha, Deok-Chan
supporting information, (2020/08/14)
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
Palladium-Containing and Metal-Free Supported Dendrons As Catalysts in Multistep Conversion of Oxygenates to Fuels
Lou, Yueyun,Shantz, Daniel F.
, p. 1328 - 1336 (2019/02/07)
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
Multifunctional phosphoramide-(S)-prolinamide derivatives as efficient organocatalysts in asymmetric aldol and Michael reactions
Cruz-Hernández, Carlos,Landeros, José M.,Juaristi, Eusebio
supporting information, p. 5455 - 5465 (2019/04/05)
The synthesis and evaluation of three novel chiral organocatalysts derived from (S)-proline and containing a bis-amidophosphoryl amine fragment are reported. The structure and conformation of the new compounds were determined by NMR spectroscopy and X-ray crystallographic analysis. The present study represents an effort directed to enhance the performance of (S)-proline-derived organocatalysts in asymmetric aldol and Michael reactions by means of increased steric interactions arising from the incorporation of naphthyl moieties in the catalysts. In the event, the stereoselectivity achieved with naphthyl substituents turned out to be rather similar to that obtained with phenyl analogs. Nevertheless, the new organocatalysts exhibited rather good enantio- and diastereoselectivities in aldol reactions with various isatins and aryl carbaldehydes, affording products with up to 94?:?6 diastereomeric ratios and enantiomeric ratios as high as 95?:?5. Furthermore, products obtained from Michael addition reactions exhibited up to 96?:?4 diastereomeric ratios and enantiomeric ratios as high as 98?:?2.
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
Cruz-Hernández, Carlos,Hernández-González, Perla E.,Juaristi, Eusebio
, p. 3445 - 3459 (2018/06/08)
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
Enantiopure cis- and trans-2-(2-Aminocyclohexyl)phenols: Effective Preparation, Solid-State Characterization, and Application in Asymmetric Organocatalysis
Tezeren, Mustafa A.,Ye?il, Tolga A.,Zorlu, Yunus,Tilki, Tahir,Ertürk, Erkan
, p. 7017 - 7032 (2018/12/13)
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.
Highly efficient organocatalysts for the asymmetric aldol reaction
Jacoby,Vontobel,Bach,Schneider
, p. 7416 - 7421 (2018/05/04)
A new class of bifunctional organocatalysts containing both thiazolidine/pyrrolidine and imidazole cycles was prepared via a readily available synthetic route. The highly efficient five step methodology did not require intermediary purification and provid
Monofunctional primary amine: A new class of organocatalyst for asymmetric Aldol reaction
Vanlaldinpuia, Khiangte,Bora, Porag,Bez, Ghanashyam
, p. 301 - 312 (2017/03/23)
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
