17448-96-3Relevant academic research and scientific papers
High Pressure Mediated Diels-Alder Reaction of Furan with Dialkyl (Acetoxymethylene)malonate
Sera, Akira,Ohara, Meguru,Kubo, Toshiaki,Itoh, Kuniaki,Yamada, Hiroaki,et al.
, p. 5460 - 5464 (1988)
The Diels-Alder reaction of furan with dialkyl (acetoxymethylene)malonates 1 did not proceed even in the presence of Lewis acid catalysts under conventional conditions.However, the reaction under high pressure (1.1 GPa) gave the expected cycloadducts, dialkyl 3-acetoxy-7-oxabicyclohept-5-ene-2,2-dicarboxylates 2.The bis-, tris-, and tetrakisadducts 3-6 were also produced in some amounts.Similar high-pressure reactions in the presence of zinc iodide as a catalyst yielded dialkyl 2-furfurylidenemalonate 8, and none of the adducts were obtained.
Exploration of the Role of Double Schiff Bases as Catalytic Intermediates in the Knoevenagel Reaction of Furanic Aldehydes: Mechanistic Considerations
Van Schijndel, Jack,Canalle, Luiz Alberto,Molendijk, Dennis,Meuldijk, Jan
, p. 1983 - 1988 (2018)
This paper presents mechanistic considerations on an efficient, green, and solvent-free Knoevenagel procedure for the chemical transformation of furanic aldehydes into their corresponding α,β-unsaturated compounds. In the proposed mechanism furanic aldehydes react with ammonia, released from ammonium salts, to form a catalytically active double Schiff base. The catalytic intermediates involved in the condensation step are characterized.
α,β-Unsaturated esters from the tri-n-butylarsine-promoted reaction of bromomalonic esters with aldehydes
Shen, Yanchang,Yang, Baozhen
, p. 45 - 50 (1989)
A convenient synthesis of α,β-unsaturated esters (in 68-96percent yields) from the reaction of a bromomalonic ester with aldehydes promoted by tri-n-butylarsine is descriebed.A mechanism involving halophilic attack of tri-n-butylarsine leading to the formation of a salt followed by reaction with carbonyl compounds is proposed.This methodology provides a convenient route to α,β-unsaturated esters and represents an alternative to the Knoevenagel reaction.
One-pot synthesis of furfural derivatives from pentoses using solid acid and base catalysts
Shirotori, Mahiro,Nishimura, Shun,Ebitani, Kohki
, p. 971 - 978 (2014)
One-pot synthesis of (2-furanylmethylene)malononitrile, a Knoevenagel product of furfural with malononitrile, from xylose efficiently proceeded by combined use of acid Amberlyst-15 and acid-base Cr/hydrotalcites in 44% yield. Structural characterization was carried out using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy, and nitrogen adsorption measurements. The Lewis acidic properties of the highly active Cr/HT were investigated using the Meerwein-Ponndorf-Verley (MPV) reaction. It was confirmed that the prepared Cr/HT possessed the Lewis acid Cr2O 3 on the HT surface. Thus, combined use of the dispersed Lewis acid Cr2O3 and the Bronsted base HT facilitated the isomerization step of aldose into ketose and strongly promoted activity for the synthesis of furfural derivatives from aldoses through isomerization, dehydration and Knoevenagel condensation reactions in a one-pot manner. This journal is the Partner Organisations 2014.
Divergent Rearrangements of Vinylcyclopropane into Skipped Diene and Cyclopentene: Mechanism, Scope, and Limitations
Delbrassinne, Arnaud,Richald, Maximilien,Janssens, Julien,Robiette, Rapha?l
supporting information, p. 2862 - 2868 (2021/06/11)
Vinylcyclopropanes are versatile intermediates in organic synthesis which undergo various rearrangements. We report a new rearrangement of vinylcyclopropane into skipped diene. A detailed mechanistic study revealed that this transformation involves regioselective ring-opening of the cyclopropane ring followed by 1,2-migration of one of the cyclopropane substituents. Interestingly, our investigations showed that skipped diene is the kinetic product of the process but formation of a more stable cyclopentene is also accessible. The fundamental understanding of the processes involved enabled the development of divergent methodologies allowing to obtain cyclopentene or skipped diene from vinylcyclopropane in a selective and controlled manner.
Johnson-Corey-Chaykovsky fluorocyclopropanation of double activated alkenes: Scope and limitations
Kazia, Armands,Melngaile, Renate,Mishnev, Anatoly,Veliks, Janis
supporting information, p. 1384 - 1388 (2020/03/03)
Johnson-Corey-Chaykovsky fluorocyclopropanation of double activated alkenes utilizing S-monofluoromethyl-S-phenyl-2,3,4,5-tetramethylphenylsulfonium tetrafluoroborate is an efficient approach to obtain a range of monofluorocyclopropane derivatives. So far, fluoromethylsulfonium salts have displayed the broadest scope for direct fluoromethylene transfer. In contrast to more commonly used fluorohalomethanes or freon derivatives, diarylfluoromethylsulfonium salts are bench stable, easy-to use reagents useful for the direct transfer of a fluoromethylene group to alkenes giving access to the challenging products-fluorocyclopropane derivatives. Interplay between the reactivity of the starting materials and stability of the fluorocyclopropanes formed determines the outcome of the process.
Metal free biomimetic deaminative direct C-C coupling of unprotected primary amines with active methylene compounds
Ghosh, Santanu,Jana, Chandan K.
supporting information, p. 10153 - 10157 (2019/12/26)
An unprecedented direct C-C coupling reaction of unprotected primary amines with active methylene compounds is reported. The reaction involves a biomimetic deamination of amines which was achieved under conditions free of metallic reagents and strong oxidizing agents. A wide range of primary amines was reacted with different active methylene compounds to provide structurally diverse trisubstituted alkenes and dihydropyridines. A kinetic study revealed an activation barrier of 10.1 kcal mol-1 for the conversion of a key intermediate of the reaction.
Unnatural α-amino ethyl esters from diethyl malonate or ethyl β-bromo-α-hydroxyiminocarboxylate
Coutant, Eloi P.,Hervin, Vincent,Gagnot, Glwadys,Ford, Candice,Baatallah, Racha,Janin, Yves L.
supporting information, p. 2853 - 2860 (2018/11/26)
We have explored here the scope of the age-old diethyl malonate-based accesses to α-amino esters involving Knoevenagel condensations of diethyl malonate on aldehydes, reductions of the resulting alkylidenemalonates, the preparation of the corresponding α-hydroxyimino esters and their final reduction. This synthetic pathway turned out to be general although some unexpected limitations were encountered. The synthetic modifications of some of the intermediates - using Suzuki-Miyaura coupling or cycloadditions - before undertaking the oximation step - provided accesses to further α-amino esters. Moreover, other pathways to α-hydroxyimino esters were explored including an attempt to improve the cycloadditions between ethyl β-bromo-α-hydroxyiminocarboxylate and various alkylfuranes.
Knoevenagel condensation of diethylmalonate with aldehydes catalyzed by immobilized bovine serum albumin (BSA)
Ramesh, Perla,Shalini, Basetty,Fadnavis, Nitin W.
, p. 7368 - 7373 (2014/02/14)
Knoevenagel condensation between aldehydes and diethylmalonate is catalyzed efficiently by bovine serum albumin (BSA) immobilized covalently on an epoxy-functionalized polymeric support, Immobead IB-350. The reaction is carried out conveniently at room temperature in DMSO in which aliphatic, heterocyclic and aromatic aldehydes react efficiently. After extraction with heptane and treatment with Candida antarctica lipase CAL B, the products are obtained in >95% purity and 85-89% yield. The solvent DMSO, unreacted diethylmalonate and immobilized BSA were easily recovered. Immobilized BSA and recovered DMSO were recycled 5 times without any appreciable loss in yield.
Design and synthesis of 6-oxo-1,4,5,6-tetrahydropyrimidine-5-carboxylate derivatives as neuraminidase inhibitors
Lou, Jun,Yang, Xiaoyan,Rao, Zhigang,Qi, Wenwen,Li, Jinhui,Wang, Haiyu,Li, Yuxi,Li, Jinping,Wang, Zhiming,Hu, Xianming,Liu, Peng,Hong, Xuechuan
, p. 466 - 473 (2014/07/21)
A series of 6-oxo-1,4,5,6-tetrahydropyrimidine-5-carboxylate derivatives were prepared to evaluate their ability of inhibiting neuraminidase (NA) of influenza A virus. All the compounds were synthesized in good yields starting from aldehyde by using a suitable synthetic strategy, which showed moderate inhibitory activity against influenza A NA. Compound 6g exhibited the strongest inhibitory activity against influenza virus A NA (IC50 = 17.64 μM), which indicated pyrimidine ring could be used as a core structure to design novel influenza NA inhibitors.
