688802-13-3Relevant academic research and scientific papers
Synthesis of a new chiral organocatalyst derived from (S)-proline containing a 1,2,4-triazolyl moiety and its application in the asymmetric aldol reaction. Importance of one molecule of water generated in situ
Sánchez-Antonio, Omar,Juaristi, Eusebio
, (2019)
A simple and efficient preparation of a novel chiral derivative of (S)-proline containing a 1,2,4-triazolyl moiety is described. The high-yielding synthetic protocol includes the use of microwave irradiation to afford new chiral pyrrolidine derivatives in
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
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.
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.
New prolinamides with isosteviol skeleton as efficient organocatalysts for the direct asymmetric aldol reaction
Liu, Yu-Xia,Ma, Zhi-Wei,Li, Yan-Xun,Tao, Jing-Chao
, p. 307 - 313 (2018/04/20)
Abstract: In this work, two new prolinamides with isosteviol skeleton were synthesized and used as chiral catalysts for the asymmetric aldol reaction. Solvent effects, catalyst loading, substrate scope and the influence of water on the reaction were inves
Combining prolinamides with 2-pyrrolidinone: Novel organocatalysts for the asymmetric aldol reaction
Vlasserou, Ismini,Sfetsa, Maria,Gerokonstantis, Dimitrios-Triantafyllos,Kokotos, Christoforos G.,Moutevelis-Minakakis, Panagiota
, p. 2338 - 2349 (2018/04/06)
Peptides and especially prolinamides have been identified as excellent organocatalysts for the aldol reaction. The combination of prolinamides with derivatives bearing the 2-pyrrolidinone scaffold, deriving from pyroglutamic acid, led to the identification of novel organocatalysts for the intermolecular asymmetric aldol reaction. The new hybrids were tested both in organic and aqueous media. Among the compounds tested, 22 afforded the best results in petroleum ether, while 25 afforded the products in brine in high yields and selectivities. Then, various ketones and aldehydes were utilized and the products of the aldol reaction were obtained in high yields (up to 100%) with excellent diastereo- (up to 97:3 dr) and enantioselectivities (up to 99% ee).
Proline dipeptides containing fluorine moieties as oganocatalysts for the asymmetric aldol reaction
Ahmetlli, Ardiol,Spiliopoulou, Nikoleta,Magi-Oikonomopoulou, Angeliki,Gerokonstantis, Dimitrios-Triantaffylos,Moutevelis-Minakakis, Panagiota,Kokotos, Christoforos G.
, p. 5987 - 5995 (2018/09/21)
A series of dipeptide analogues consisting of proline, phenylalanine and aniline- or phenol-fluorine derivatives were synthesized. Their catalytic ability was evaluated in the intermolecular asymmetric aldol reaction, both in organic and aqueous media. Aniline-fluorine derivatives proved to be superior and the best results were obtained, when 2-CF3 aniline was employed. A diverse substrate scope consisting of both aromatic and aliphatic aldehydes, as well as different ketones was demonstrated, where aromatic aldehydes afforded products in high yields (up to 100%) with excellent diastereo- (up to 95:5) and enantioselectivities (up to 97%), whereas the aliphatic aldehydes afforded also excellent selectivities, but relatively low yield. A simple addition of fluorine to a dipeptide analogue affords organocatalysts with new interesting properties that can catalyze the aldol reaction more efficiently.
L-proline derivatives based on a calix[4]arene scaffold as chiral organocatalysts for the direct asymmetric aldol reaction in water
Aktas, Mehmet,Uyanik, Arzu,Eymur, Serkan,Yilmaz, Mustafa
, p. 351 - 359 (2016/04/19)
A new series of water-compatible proline catalysts (4-6) derived from calixarene bearing a hydrophobic nature have been synthesised. It was found that the compound 4 was a highly efficient organocatalyst for aldol reactions occurred in the water. Under op
Polymerization of L-proline functionalized styrene and its catalytic performance as a supported organocatalyst for direct enantioselective aldol reaction
Guo, Guozhang,Wu, Yufeng,Zhao, Xiaowei,Wang, Jing,Zhang, Lei,Cui, Yuanchen
, p. 740 - 746 (2016/08/01)
As an alternative approach to the graft modification of polymers to fabricate polymer-supported chiral organocatalysts in a bottom-up fashion, L-prolinamide functionalized polymers were prepared by general solution homopolymerization or copolymerization of L-proline functionalized styrene monomer in the presence of 1,4-divinylbenzene as the crosslinking agent. The catalytic performance of the as-prepared heterogeneous catalysts towards the direct enantioselective aldol reaction of ketones with a series of aromatic aldehydes was explored. Our findings indicate that the as-prepared heterogeneous catalysts can afford relevant aldol addition products with good yields (up to 96%), high diastereoselectivities (up to 8:92 dr) and excellent enantiomeric excess (up to 96%); they also exhibit good recyclability, retaining high yield and rate as well as good selectivity after several cycles.
A comprehensive study on the effect of acid additives in 1( R),2( R)-Bis[(S)-prolinamido]cyclohexane catalyzed direct asymmetric aldol reactions in aqueous media
Bhowmick, Sudipto,Kunte, Sunita S.,Bhowmick, Kartick C.
, p. 84 - 92 (2015/01/30)
The catalytic efficacy of (1R,2 R)-bis[(S)-prolinamido]cyclohexane 1, prepared from the readily available natural amino acid L-proline has been studied for the direct asymmetric aldol reaction of cyclohexanone with substituted benzaldehydes at room temper
