24405-46-7Relevant academic research and scientific papers
Asymmetric Synthesis of Pentasubstituted Cyclohexanes through Diphenylprolinol Silyl Ether Mediated Domino Michael/Michael Reaction
Odoh, Amaechi Shedrack,Aidanp??, Louise,Umekubo, Nariyoshi,Matoba, Hiroaki,Mori, Naoki,Hayashi, Yujiro
supporting information, p. 6670 - 6673 (2021/12/31)
An asymmetric domino Michael/Michael reaction of α,β-unsaturated aldehydes 1 and α-acetyl-β-substituted-α,β-unsaturated esters 2 catalyzed by diphenylprolinol silyl ether was developed. This is a formal carbo [4+2] cycloaddition reaction affording penta-s
Highly efficient FeNP-embedded hybrid bifunctional reduced graphene oxide for Knoevenagel condensation with active methylene compounds
Patel, Dikin,Vithalani, Ravi,Modi, Chetan K.
, p. 2868 - 2881 (2020/03/03)
We have synthesized atypical highly active bifunctional FeNPs implanted on amino-modified reduced graphene oxide (FeNPs/Am@rGO) [where FeNPs = Fe nanoparticles; Am = Primary aromatic amine derivatives such as p-phenylenediamine (PPD) and/or aniline (AN)]
Cross-linked polystyrene-TiCl4 complex as a reusable Lewis acid catalyst for solvent-free Knoevenagel condensations of 1,3-dicarbonyl compounds with aldehydes
Rahmatpour, Ali,Goodarzi, Niloofar
, p. 24 - 31 (2019/03/08)
Cross-linked polystyrene copolymer beads with the average particle size in the range of (50–80 mesh size) were prepared by a new method, characterized and functionalized with titanium tetrachloride to afford the corresponding polystyrene?titanium tetrachloride complex in one step reaction and characterized by FT-IR, UV, TGA, DSC, XRD, SEM, BET. This polymer metal complex (PS/TiCl4) was used as a heterogeneous, recoverable, reusable Lewis acid for solvent-free Knoevenagel condensations of 1,3-diketones with aromatic aldehydes under green and mild conditions. The rate of reactions was found to decrease with an increasing percentage of crosslinking and the mesh size of the copolymer beads. This complex showed good stability and catalytic activity in the Knoevenagel reactions.
Enzyme Promiscuity as a Remedy for the Common Problems with Knoevenagel Condensation
Koszelewski, Dominik,Ostaszewski, Ryszard
, p. 10156 - 10164 (2019/07/09)
A new protocol based on lipase-catalyzed tandem reaction toward α,β-enones/enoesters is presented. For the synthesis of the desired products the tandem process based on enzyme-catalyzed hydrolysis and Knoevenagel reaction starting from enol acetates and aldehyde is developed. The relevant impact of the reaction conditions including organic solvent, enzyme type, and temperature on the course of the reaction was revealed. It was shown that controllable release of the active methylene compound from the corresponding enol carboxylate ensured by enzymatic reaction diminishes significantly the formation of the unwanted co-products. Furthermore, this protocol was extended by including a second tandem chemoenzymatic transformation engaging various aldehyde precursors. After a careful optimization of the reaction conditions, the target products were obtained with yields up to 86 % and with excellent E/Z-selectivity.
Facile construction of 4H-chromenes via Michael addition of phenols to benzylidene oxobutanoates and their successful conversion into pyranocoumarins
Priyanka,Sharma, Rajesh K.,Butcher, Ray J.,Katiyar, Diksha
supporting information, p. 2347 - 2351 (2018/05/24)
An efficient and simple approach for the synthesis of functionalized 4H-chromenes has been developed via acid catalyzed Michael addition of phenols to benzylidene oxobutanoates. Preliminary mechanistic studies were conducted, suggesting that intermediate
Bioreduction of α-Acetoxymethyl Enones: Proposal for an SN2′ Mechanism Catalyzed by Enereductase
Paula, Bruno R. S.,Zampieri, Davila,Rodrigues, J. Augusto R.,Moran, Paulo J. S.
, p. 3555 - 3571 (2016/11/25)
(Z)-3-Acetoxymethyl-4-R-3-buten-2-ones (R=aryl, alkyl) and (Z)-3-methyl-4-R-3-buten-2-ones (R=aryl) were synthesized and submitted to reduction by the yeast Saccharomyces cerevisiae producing the (R)- and (S)-4-R-3-methybutan-2-ones, respectively. This stereochemistry control strategy was applied in the syntheses of (R)- and (S)-Tropional with moderate to high enantiomeric excesses. Other (Z)-3-acyloxymethyl-4-phenyl-3-buten-2-ones showed similar behavior to the (Z)-3-acetoxymethyl counterpart, and the acylated Morita–Baylis–Hillman adduct 1-acetoxy-2-methylene-1-phenylbutan-3-one produced a mixture of products, with and without the acetoxy group, via three different reaction pathways. In addition to experiments employing whole cells, those in which isolated enereductases were used suggested that the main pathway through which the loss of the acetoxy group occurs during the biocatalytic cascade is an SN2′-type reaction, rather than formal hydrogen addition followed by acetic acid elimination. Finally, related ethyl enones were reduced enantioselectively by the yeast Candida albicans, producing both (R)- and (S)-reduction products, depending on the presence of the acetoxy group in the starting material. (Figure presented.).
Visible-light-promoted iminyl-radical formation from Acyl oximes: A unified approach to pyridines, quinolines, and phenanthridines
Jiang, Heng,An, Xiaode,Tong, Kun,Zheng, Tianyi,Zhang, Yan,Yu, Shouyun
supporting information, p. 4055 - 4059 (2015/03/30)
A unified strategy involving visible-light-induced iminyl-radical formation has been established for the construction of pyridines, quinolines, and phenanthridines from acyl oximes. With fac-[Ir(ppy)3] as a photoredox catalyst, the acyl oximes were converted by 1 e- reduction into iminyl radical intermediates, which then underwent intramolecular homolytic aromatic substitution (HAS) to give the N-containing arenes. These reactions proceeded with a broad range of substrates at room temperature in high yield. This strategy of visible-light-induced iminyl-radical formation was successfully applied to a five-step concise synthesis of benzo[c]phenanthridine alkaloids.
Raman spectroscopy as a tool for monitoring mesoscale continuous-flow organic synthesis: Equipment interface and assessment in four medicinally-relevant reactions
Hamlin, Trevor A.,Leadbeater, Nicholas E.
supporting information, p. 1843 - 1852 (2013/10/22)
An apparatus is reported for real-time Raman monitoring of reactions performed using continuous-flow processing. Its capability is assessed by studying four reactions, all involving formation of products bearing α,β-unsaturated carbonyl moieties; synthesi
Design, synthesis and computational validation of novel benzimidazole/indole-based PPARα and PPAR? partial agonists
Verma, Raman K.,Ghosh, Prithwish,Kumar, Vijay,Wadhwa, Lalit K.
, p. 1555 - 1571 (2014/04/03)
The design and synthesis of benzimidazolyl and indolyl linked α-alkoxy phenylpropanoic acid derivatives and the β-keto ester analogues in an effort to develop novel peroxisome proliferator activated receptors ligands expected to exhibit PPARα and PPAR? pa
Design and synthesis of 4-alkyl-2-amino(acetamino)-6-aryl-1,3-thiazine derivatives as influenza neuraminidase inhibitors
Li, Wan,Xia, Lin,Hu, Aixi,Liu, Ailin,Peng, Junmei,Tan, Weiqing
, p. 635 - 644 (2013/09/24)
With a convenient and economical method, two series of 1,3-thiazine derivatives 1 and 2 were synthesized, and their neuraminidase (NA) inhibitory activities were evaluated. The pharmacological results showed that most of the compounds have potent NA inhibitory activity. Especially, 1g exhibited the best activity against influenza virus A (H1N1) NA (IC50 = 29.06 μg/mL), and its crystal structure was determined by single-crystal X-ray diffraction. The preliminary biological assay indicated that 1,3-thiazine could be used as a core structure to design novel influenza NA inhibitors. Two series of novel 1,3-thiazine analogs were synthesized and their neuraminidase (NA) inhibitory activities were evaluated. Most of the compounds have potent NA inhibitory activity. Compound 1g exhibited the best activity against influenza virus A (H1N1) NA with an IC50 of 29.06 μg/mL, and its crystal structure was determined by single-crystal X-ray diffraction.
