5381-93-1Relevant academic research and scientific papers
Combination of a Metal-N-Heterocyclic-Carbene Catalyst and a Chiral Aminocatalyst within a Covalent Organic Framework: A Powerful Cooperative Approach for Relay Asymmetric Catalysis
Li, Yue,Wang, Jin-Mei,Kan, Jing-Lan,Li, Fei,Dong, Ying,Dong, Yu-Bin
, p. 2455 - 2462 (2022/01/31)
Incorporation of metal catalysis and organocatalysis has emerged as a promising way for developing new and valuable organic reactions. This catalytic strategy would potentially enable unprecedented transformations not possible by the existing metal cataly
Chiral Bipyridine Ligand with Flexible Molecular Recognition Site: Development and Application to Copper-Catalyzed Asymmetric Borylation of α,β-Unsaturated Ketones
Tsutsumi, Ryosuke,Taguchi, Rika,Yamanaka, Masahiro
, (2021/10/20)
A novel chiral bipyridine ligand bearing a flexible side chain with a molecular recognition site enables precise stereocontrol through the cooperative action of metal center and hydrogen bonds. This new chiral ligand was applied to the copper-catalyzed as
Defect-Engineered Chiral Metal-Organic Frameworks for Efficient Asymmetric Aldol Reaction
Chen, Zijuan,Yan, Xiaodan,Li, Meiyan,Wang, Shuhua,Chen, Chao
supporting information, p. 4362 - 4365 (2021/05/04)
By employment of a mixed truncated chiral ligand synthetic strategy, a defect-engineered chiral metal-organic framework with hierarchical micro/mesoporous structure was prepared, and it exhibited efficient heterogeneous catalytic activity and enantioselectivity for asymmetric aldol reaction.
Near-infrared laser–assisted CuS@mSiO2@L-proline catalyzed asymmetric aldol reaction
Hu, Enyan,Li, Guohua,Xu, Longjun,Zhang, Xiaorui
, (2021/06/22)
Mesoporous silica-coated copper sulfide nanosheet-loaded L-proline catalysts were prepared to catalyze the hydroxyl aldol condensation reaction using 808-nm laser assistance. The catalysts were characterized by X-ray powder diffraction, scanning electron
Chiral imidazolium prolinate salts as efficient synzymatic organocatalysts for the asymmetric aldol reaction
Altava, Belén,Burguete, Maria Isabel,García-Verdugo, Eduardo,Luis, Santiago V.,Porcar, Raúl
supporting information, (2021/07/26)
Chiral imidazolium L-prolinate salts, providing a complex network of supramolecular interaction in a chiral environment, have been studied as synzymatic catalytic systems. They are demonstrated to be green and efficient chiral organocatalysts for direct asymmetric aldol reactions at room temperature. The corresponding aldol products were obtained with moderate to good enantioselectivities. The influence of the presence of chirality in both the imidazolium cation and the prolinate anion on the transfer of chirality from the organocatalyst to the aldol product has been studied. Moreover, interesting match/mismatch situations have been observed regarding configuration of chirality of the two components through the analysis of results for organocatalysts derived from both enantiomers of prolinate (R/S) and the trans/cis isomers for the chiral fragment of the cation. This is associated with differences in the corresponding reaction rates but also to the different tendencies for the formation of aggregates, as evidenced by nonlinear effects studies (NLE). Excellent activities, selectivities, and enantioselectivities could be achieved by an appropriate selection of the structural elements at the cation and anion.
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
Highly enantioselective immobilized prolinamide-catalyzed aldol reactions in continuous-flow systems: effect of water on the catalyst lifetime and application in the synthesis of a chiral fenpentadiol analogue
Yue, Caizhen,Yamashita, Yasuhiro,Kobayashi, Shū
supporting information, p. 1989 - 1994 (2021/03/26)
Catalytic enantioselective aldol reactions of trifluoroacetophenones with ketones under continuous-flow conditions have been developed for the first time by using polystyrene-supported prolinamides. The robustness of the flow system was demonstrated by the continuous synthesis of a variety of trifluoromethyl carbinols in high yields with high enantioselectivities. The unusually long lifetimes (>195 h) of this flow process were achieved by facilitating H2O-promoted hydrolysis of iminium intermediates on the polymer. Mechanistic study revealed a racemization phenomenon and an inherent reversible property of the aldol reactions in a conventional batch system, both of which were suppressed under continuous-flow conditions. The synthetic utility of this flow process was further demonstrated by the formal continuous-flow synthesis of a chiral fenpentadiol analogue.
TIPS-Diazoacetone Aldol Addition: Mechanistic Aspects and Contribution to the Synthesis
Gavelle, Sigrid,Abid, Imen,Biletskyi, Bohdan,Henrion, Sylvain,Hémon-Ribaud, Annie,Lhoste, Jér?me,Martel, Arnaud,Dujardin, Gilles,Gaulon-Nourry, Catherine
, p. 4917 - 4931 (2021/04/12)
Aldol addition of α-triisopropylsilyl-α-diazoacetone (TIPS-diazoacetone), promoted by excess lithium diisopropylamide (LDA), was developed and applied to the synthesis of original C-TIPS diazoaldols, C-TIPS diazoketols, and a related Mannich-type product. An unprecedented mechanistic pathway has been proposed, involving a lithiated triazene intermediate resulting from the nucleophilic addition of LDA on the diazo moiety, supported by experimental results and DFT calculations.
Highly tunable selectivity to benzaldehyde over Pd/ZrO2 catalysts in Oppenauer oxidation of benzyl alcohol using acetone as H-acceptor
Akinnawo, Christianah Aarinola,Maheso, Dimakatso Jeannett,Bingwa, Ndzondelelo,Meijboom, Reinout
, (2021/02/12)
The development of novel bifunctional catalysts with high selectivity is the key to achieving the goals of sustainable chemical synthesis. Here, we report the synthesis of mesoporous zirconia and transition metal-doped zirconia by inverse micelle approach. Also, meso-zirconia supported Pd nanocatalysts via the deposition-precipitation method. Highly crystalline Pd/ZrO2 nanoparticles were formed, as evidenced in the pXRD and TEM analyses. The acid-base quantification was investigated using TPD-NH3 and TPD-CO2. Interestingly, the integration of the intrinsic chemical properties of the multi-component catalyst is significant in tailoring the catalytic activities. Interactions between the adsorbates and the moderate acid-base pair sites rather than a single dominating acid or base site mediate the higher selectivity for the aldehyde product. The 100 % chemoselectivity to benzaldehyde is ascribed to the strong synergy between Pd-Zr, which generated the moderate acid-base property. The Pd/ZrO2 is reusable, with selectivity retained after ten cycles.
Cellulosic CuI Nanoparticles as a Heterogeneous, Recyclable Catalyst for the Borylation of α,β-Unsaturated Acceptors in Aqueous Media
Zhou, Lijie,Han, Biao,Zhang, Yaoyao,Li, Bojie,Wang, Liansheng,Wang, Jianying,Wang, Xianbao,Zhu, Lei
, p. 3220 - 3229 (2021/03/06)
Abstract: We have demonstrated that cellulosic CuI nanoparticles could perform as an efficient heterogeneous catalyst for the synthesis of useful organoboron compounds. Desired β-borylation products were all obtained in good to excellent yields under mild
