56072-25-4Relevant academic research and scientific papers
Dendritic HMPA as a promoter for the mukaiyama aldol and allylation reaction
Mummy, Florian,Haag, Rainer
, p. 2672 - 2676 (2012)
We synthesized a hexamethylphosphoramide (HMPA) analogue that was immobilized on hyperbranched polyglycerol (hPG) via a covalent approach. This polymeric analogue (hPG-HMPA) can potentially replace carcinogenic HMPA as a Lewis base additive in many reactions involving trichlorosilyl substrates. We investigated immobilized HMPA in the Mukaiyama aldol and allylation reactions. In most cases, yields and selectivities of supported and nonsupported HMPA were similar. Moreover, in the allylation reaction a positive dendritic effect could be observed, and the loading of HMPA could be lowered with hPG-HMPA to catalytic quantities (0.5 mol%). These results demonstrate that the use of HMPA can be avoided by hPG-HMPA without loss in terms of yield or selectivity. Georg Thieme Verlag KG Stuttgart · New York.
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.
Natural eutectogels: Sustainable catalytic systems for C-C bond formation reactions
D'Anna, Francesca,Meli, Alessandro,Ramón, Diego J.,Rizzo, Carla,Saavedra, Beatriz
supporting information, p. 6555 - 6565 (2021/09/10)
Natural eutectogels were prepared by combining the properties of amino acids with the ones of deep eutectic solvents. The soft materials obtained were fully characterised by determining the gel-sol transition temperatures and analysing the mechanical and
Homochiral bifunctional L-prolinamide- and L-bis-prolinamide-catalyzed asymmetric aldol reactions performed in wet solvent-free conditions
Anaya de Parrodi, Cecilia,Domínguez-Huerta, Alejandra,Hernández Pérez, Julio M.,Huelgas, Gabriela,Rojas Cabrera, Haydee,Sabala, Rocío,Somanathan, Ratnasamy,de la Higuera Macías, Maximiliano
supporting information, p. 22 - 36 (2020/12/04)
In this study, the novel bifunctional homochiral thiourea-L-prolinamides 1–4, tertiary amino-L-prolinamide 5, and bis-L-prolinamides 6 and 7 were prepared from enantiomerically pure (11R,12R)-11,12-diamino-9,10-dihydro-9,10-ethanoanthracene 8 and (11S,12S
Proline-Histidine Dipeptide: A Suitable Template for Generating Ion-Tagged Organocatalysts for the Asymmetric Aldol Reaction
Inani, Heena,Singh, Avtar,Bhati, Meeta,Kumari, Kiran,Kucherenko, Alexander S.,Zlotin, Sergei G.,Easwar, Srinivasan
, p. 2702 - 2712 (2021/06/02)
Proline-histidine dipeptide laid the foundation for the construction of three new ion-tagged organocatalysts, utilising the imidazole moiety of histidine for generating the quaternary species. A brief comparative investigation of the catalysts in the enam
New small γ-turn type: N -primary amino terminal tripeptide organocatalyst for solvent-free asymmetric aldol reaction of various ketones with aldehydes
Begum, Zubeda,Kwon, Eunsang,Nakano, Hiroto,Okuyama, Yuko,Seki, Chigusa,Takeshita, Mitsuhiro,Thiyagarajan, Rajkumar,Tokiwa, Michio,Tokiwa, Suguru,Uwai, Koji
, p. 38925 - 38932 (2021/12/20)
New small γ-turn type N-primary amino terminal tripeptides were synthesized and their functionality as an organocatalyst was examined in the asymmetric aldol reaction of various ketones with different aromatic aldehydes under solvent-free neat conditions to afford the desired chiral anti-aldol products in good to excellent chemical yields, diastereoselectivities and enantioselectivities (up to 99%, up to syn?:?anti/13?:?87 dr, up to 99% ee). This journal is
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
Design and preparation of a novel prolinamide-based organocatalyst for the solvent-free asymmetric aldol reaction
Martins, Rafaela de S.,Pereira, Mathias P.,de Castro, Pedro P.,Bombonato, Fernanda I.
, (2019/12/24)
The preparation of four novel organocatalysts as highly diastereo and enantioselective catalysts for the solvent-free asymmetric aldol reaction was described. These organocatalysts were synthesized in eight steps applying simple and commercially available starting materials. The best results were obtained for the proline-derived catalyst, providing access to the desired adducts in up to 95% yield, 1:19 syn/anti and 98% e.e. Moreover, even sterically bulky aldehydes and substituted cyclohexanones were well tolerated. DFT calculations and control experiments indicated that several hydrogen bonding interactions between the aldehyde and the enamine intermediate are responsible for the stereoselective chiral induction process and that the trifluoroacetate counter-anion is crucial for the attainment of higher stereoselectivities.
A recyclable and highly stereoselective multi-fluorous proline catalyst for asymmetric aldol reactions
Gotoh, Machiko,Ishihara, Kazuki,Ishihara, Kotaro,Kobayashi, Yuki,Matsugi, Masato,Obayashi, Riho,Shioiri, Takayuki,Watanabe, Yuki
, (2020/02/13)
A recyclable fluorous proline catalyst with high stereoselectivity that functions as a catalyst for asymmetric aldol reactions is described. Its high stereoselectivity and facile recovery are achieved by employing a multi-fluorous tag attachment strategy. Although a gradual decrease was observed with respect to the catalytic activity, the catalyst can be separated from the reaction mixture by adsorption onto FluoroFlash and can be reused in that form for a maximum of five times while maintaining a high stereoselectivity.2019 Elsevier Ltd. All rights reserved.
