877032-07-0Relevant articles and documents
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
Recyclable Helical Poly(phenyl isocyanide)-Supported l-Proline Catalyst for Direct Asymmetric Aldol Reaction in Brine
Li, Chonglong,Wang, Jihai,Ding, Huiyun
, p. 1180 - 1190 (2020/09/07)
Abstract: A novel helical poly(phenyl isocyanide) bearing Boc protected l-proline pendants (poly-1m) was designed and synthesized. Removed the protecting Boc groups on the l-proline pendants led to the formation of helical polymer poly-2m, which showed high optical activity owing to the preferred right-handed helix of polyisocyanide main chain. Optically active helical poly-2m showed excellent catalytic ability on asymmetric aldol reaction. Helical polymer catalysts exhibited enhanced stereoselectivity in aldol reaction compared to small molecule l-proline. Under the optimized aldol reaction condition, the enantiomeric excess (ee) and diastereomeric ratio (dr) values of the aldol reaction product were respectively up to 90% and > 20/1. Moreover, the helical polyisocyanide catalyst Poly-2m can be easily recovered and reused in the aldol reaction for at least five cycles with maintained its activity and stereoselectivity. Graphic Abstract: Enantioselective aldol reaction catalyzed by poly-2m.[Figure not available: see fulltext.]
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.
“Ship-in-a-Bottle” Strategy for Immobilization of 9-Amino(9-deoxy)epi-Cinchona Alkaloid into Molecularly Imprinted Solid Acid: Acetal Hydrolysis/Asymmetric Aldol Tandem Reaction
Wei, Shuai,Zhang, Jianing,Li, Shan,Ma, Xuebing
, p. 627 - 636 (2020/12/09)
Direct immobilization of versatile 9-amino(9-deoxy)epi-cinchona alkaloids without molecule modification to achieve heterogeneous organocatalysis is of interest in the low-cost production of optically active compounds. In this paper, an exquisite “ship-in-a-bottle” strategy for direct and simple immobilization of 9-amino-(9-deoxy)epi-quinine (QNNH2) into hollow polystyrene nano-bowl with imprinted free space around ?SO3H was developed via acid-base reaction and radical polymerization. The heterogeneous organocatalyst with 0.44 mmol g?1 of QNNH2 and 0.48 mmol g?1 of residual ?SO3H possessed fast mass transfer due to the characteristic architectural features, such as thin shell thickness, free space around catalytic site, and hollow interior. In heterogeneous acetal hydrolysis/asymmetric aldol tandem reaction, good to excellent catalytic performances (90–95 % yields, anti/syn=88/12–96/4, and 97–99 % ee anti) for acetals bearing electron-withdrawing substituents (R=o, m, p-NO2, Cl) were achieved. The “ship-in-a-bottle” QNNH2 displayed good stability and reusability with excellent catalytic performances in the reuses.
Direct Asymmetric Aldol Reaction in Continuous Flow Using Gel-Bound Organocatalysts
Schmiegel, Carsten J.,Baier, Rene,Kuckling, Dirk
, p. 2578 - 2586 (2021/06/28)
Continuous flow catalysis using a microfluidic reactor with gel-bound proline organocatalysts is an attractive approach in organic synthesis due to interesting advantages such as the permanent production of catalyst-free products and the easy product isol
Pro-phe derivatives as organocatalysts in asymmetric aldol reaction
Aydogan, Feray,Karaoglu, Merve,Yolacan, Cigdem
supporting information, p. 233 - 239 (2021/03/19)
The aldol reaction which is the most important one among the C-C bond forming reactions, is widely used by synthetic organic chemists to obtain β-hydroxycarbonyl compounds which are important starting components for biologically active compounds in optica
L-proline/cholesterol and diosgenin based thiourea cooperative system for the direct asymmetric aldol reaction in the presence of water
Eymur, Serkan,Ta?ci, Enis,Uyanik, Arzu,Yilmaz, Mustafa
, p. 1278 - 1284 (2020/11/20)
A series of cholesterol and based hydrophobic urea and thiourea compounds were synthesized and successfully used as a cocatalyst for L-proline catalyzed aldol reactions in the presence of water. The anticonfigured products were obtained with good yields (up to 94%), high diastereoselectivities (up to 95:5), and high enantiomeric excesses (up to 93% ee). The successful results for catalytic efficiency of L-proline in the presence of water reveal the importance of the hydrophobic nature of cholesterol and diosgenin parts of thiourea on the reactivity and selectivity in the presence of water.
Chiral proline sulfonamide bifunctional catalyst and preparation method and application thereof
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Paragraph 0097-0100, (2020/08/17)
The invention discloses a novel chiral sulfonamide bifunctional catalyst and a preparation method and application thereof. The catalyst comprises a compound A or a compound B. The molecular structureof the compound A is shown as a formula (I) which is des
