57270-84-5Relevant academic research and scientific papers
L-Proline based ionic liquid: A highly efficient and homogenous catalyst for synthesis of 5-benzylidene-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione and pyrano[2,3-d] pyrimidine diones under ultrasonic irradiation
Patil, Paresh G.,Satkar, Yuvraj,More, Dhananjay H.
, p. 3804 - 3819 (2020/09/01)
A catalytic, practical, efficient procedure for the synthesis of 5-benzylidene-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione and pyrano[2,3-d] pyrimidine diones at room temperature was developed using L-Proline nitrate ionic liquid under ultrasonic irradiation. The L-Proline nitrate is homogeneous and green catalyst easy to prepare by mixing L-Proline and nitric acid possess excellent catalytic activity under standard ultrasonic bath at room temperature for the synthesis of pyrimidine core. This adequate procedure offers some advantages like the use of green solvent H2O, environmentally green benign procedure, excellent yields, simple procedure, short reaction times, no need for column chromatographic separation and reusability of catalyst for five subsequent reaction.
One-Pot Knoevenagel and [4 + 2] Cycloaddition as a Platform for Calliviminones
Roy, Pritam,Anjum, S. Rehana,Ramachary, Dhevalapally B.
supporting information, p. 2897 - 2901 (2020/04/15)
Bioactive compounds featuring an unusual core of spiro[5.5]undecenes and calliviminones were synthesized in very good yield with good regio- and diastereoselectivities through a one-pot Knoevenagel and [4 + 2] cycloaddition from the readily available aldehydes, cyclic-1,3-diones, dienes, and a catalytic amount of (s)-proline.
Palladium-Catalyzed [5 + 2] Annulation of Vinylethylene Carbonates with Barbiturate-Derived Alkenes
Chen, Yuehua,Deng, Hao,Gao, Xing,Guo, Hongchao,Jiang, Feng,Wang, Wei,Wu, Yongjun,Zhu, Dongyu
supporting information, p. 7158 - 7163 (2020/10/02)
A palladium/XantPhos-catalyzed [5 + 2] annulation of VECs with electron-deficient alkenes having an isolated carbon-carbon double bond has been developed to afford spirobarbiturate-tetrahydrooxepines. This study provides an expedient assembly of biologically interesting spirobarbiturate-tetrahydrooxepines. The easy scalability and versatile transformability of the reaction products were also exhibited.
Synthesis of spirobarbiturate-pyrrolidinones: Via a domino aza-Michael/SN2 cyclization of barbiturate-derived alkenes with N-alkoxy α-haloamides
Wang, Chuan-Chuan,Zhou, Jing,Ma, Zhi-Wei,Chen, Xiao-Pei,Chen, Ya-Jing
supporting information, p. 9200 - 9208 (2019/11/05)
A highly efficient domino aza-MIRC (Michael Induced Ring Closure) reaction between barbiturate-derived alkenes and N-alkoxy α-haloamides has been achieved in moderate to excellent yields. This reaction proceeds smoothly under mild conditions via a domino aza-Michael addition/intramolecular SN2 sequence, providing a practical tool in the synthesis of bioactive molecules spirobarbiturate-3-pyrrolidinones.
Dynamic Covalent Metathesis in the C=C/C=N Exchange between Knoevenagel Compounds and Imines
Gu, Ruirui,Flidrova, Karolina,Lehn, Jean-Marie
supporting information, p. 5560 - 5568 (2018/05/01)
Fast and reversible dynamic covalent C=C/C=N exchange takes place without catalyst in nonpolar solvents between barbiturate-derived Knoevenagel (Kn) compounds and imines. A detailed study of the reaction indicates that it proceeds by an associative organo-metathesis mechanism involving the formation of a four-membered ring azetidine intermediate by addition of the imine C=N group to the C=C bond of the Kn compound. This intermediate could be generated cleanly and stabilized at low temperature by condensation of the o,p-dinitrophenyl Kn derivative with the cyclic imine 1-azacyclohexene. It was characterized by extensive NMR and mass spectrometric studies. The process described represents a genuine dynamic covalent organo-metathesis through a four-membered ring adduct as intermediate. It paves the way for the exploration of a wide set of dynamic systems involving (strongly) polarized C=C bonds and various imines, extending also into covalent dynamic polymers and polymolecular assemblies.
Efficient one-pot synthesis of some new pyrimido[5′,4′:5,6]pyrido[2,3-d]pyrimidines catalyzed by magnetically recyclable Fe3O4 nanoparticles
Fattahi,Davoodnia,Pordel
, p. 863 - 867 (2017/05/29)
The study is devoted to one-pot reaction of 1,3-dimethylbarbituric acid with aromatic aldehydes and ammonium acetate using Fe3O4 nanoparticles as efficient and magnetically recyclable catalysts. Aromatic aldehydes substituted with electron-withdrawing groups or none, reacted successfully with 1,3-dimethylbarbituric acid and ammonium acetate to give new pyrimido[5′,4′:5,6]pyrido[2,3-d]pyrimidine derivatives (can be also named as pyrido[2,3-d:6,5-d′]dipyrimidines) in high yields over relatively short reaction time. The Knoevenagel condensation products were isolated using aromatic aldehydes bearing electron-donating substituents. The catalyst could be efficiently used for four times without substantial reduction in its activity. The new products were characterized on the basis of FT-IR, 1H NMR and 13C NMR spectral data.
“On-water” catalyst-free, one-pot synthesis of quaternary centered and spiro-tetrahydrothiophene-barbiturate hybrids
Nagaraju, Sakkani,Sathish, Kota,Paplal, Banoth,Kashinath, Dhurke
supporting information, p. 2865 - 2871 (2017/06/27)
A green and efficient method have been developed for the synthesis of quaternary centered and spiro-barbiturate-tetrahydrothiophene hybrids via Knoevenagel condensation,1,4-thia-Michael and intramolecular Aldol reactions using “on water” concept under catalyst-free conditions. Systematic studies were carried out to find the role of the water and total reaction concentration (0.086?M) to promote the reaction in two steps (one-pot). The use of water as a reaction medium, catalyst-free conditions, broad substrate scope, one-pot approach for the creation of quaternary centered and spiro molecules are the advantages of this method.
Asymmetric Construction of Highly Functionalized Spirobarbiturate-Cyclopentenes through Chiral Phosphine-Catalyzed [3+2] Annulation of Morita–Baylis–Hillman Carbonates with Barbiturate-Derived Alkenes
Liu, Yang,Yang, Wenjun,Wu, Yang,Mao, Biming,Gao, Xing,Liu, Honglei,Sun, Zhanhu,Xiao, Yumei,Guo, Hongchao
supporting information, p. 2867 - 2872 (2016/09/16)
A multifunctional chiral phosphine-catalyzed enantioselective [3+2] annulation of Morita–Baylis–Hillman carbonates with barbiturate-derived alkenes has been achieved under mild conditions, providing a variety of chiral spirobarbiturate-cyclopentenes in moderate to excellent yields with moderate to excellent diastereo- and enantioselectivities. (Figure presented.).
Mechanism of hydride transfer reaction from β-substituted carbanions to a carbocation
Liu, Fengrui,Yan, Shengyi,Zhu, Xiaoqing
supporting information, p. 1125 - 1127 (2014/07/22)
Mechanism of hydride transfer reactions to form olefins is still a conundrum. Here, we propose an electron transfer (ET) followed by hydrogen atom transfer (HT) as the most likely mechanism for hydride transfer reactions from the hydride adducts of olefins (G-XH-) to a carbocation (T+) in acetonitrile. This is confirmed by the analysis of the energetics of each mechanistic step, estimated from ΔHH - (the hydride affinity) and redox potentials of the related species, and activation energetics calculated from rate constants of the hydride transfer from G-XH- to T+.
Determination of thermodynamic affinities of various polar olefins as hydride, hydrogen atom, and electron acceptors in acetonitrile
Cao, Ying,Zhang, Song-Chen,Zhang, Min,Shen, Guang-Bin,Zhu, Xiao-Qing
, p. 7154 - 7168 (2013/08/23)
A series of 69 polar olefins with various typical structures (X) were synthesized and the thermodynamic affinities (defined in terms of the molar enthalpy changes or the standard redox potentials in this work) of the polar olefins obtaining hydride anions, hydrogen atoms, and electrons, the thermodynamic affinities of the radical anions of the polar olefins (X ?-) obtaining protons and hydrogen atoms, and the thermodynamic affinities of the hydrogen adducts of the polar olefins (XH?) obtaining electrons in acetonitrile were determined using titration calorimetry and electrochemical methods. The pure Ci - 'C π-bond heterolytic and homolytic dissociation energies of the polar olefins (X) in acetonitrile and the pure Ci - 'C π-bond homolytic dissociation energies of the radical anions of the polar olefins (X?-) in acetonitrile were estimated. The remote substituent effects on the six thermodynamic affinities of the polar olefins and their related reaction intermediates were examined using the Hammett linear free-energy relationships; the results show that the Hammett linear free-energy relationships all hold in the six chemical and electrochemical processes. The information disclosed in this work could not only supply a gap of the chemical thermodynamics of olefins as one class of very important organic unsaturated compounds but also strongly promote the fast development of the chemistry and applications of olefins.
