3-Quinuclidinol as a nucleophilic catalyst for the cyanation of 2-chloropyrimidines

3-Quinuclidinol serves as an effective nucleophilic catalyst for the preparation of 2-cyanopyrimidines by cyanation of 2-chloropyrimidines with potassium cyanide in good yields.     

Less reactive ketones as electrophiles and acrylamides as activated alkenes in intramolecular Baylis–Hillman reaction: facile synthesis of functionalized γ-lactam frameworks

Less reactive ketones and acrylamides have been successfully employed as electrophiles and activated alkenes, respectively, in intramolecular Baylis–Hillman reaction, thus providing a facile protocol for obtaining functionalized α-methylene-γ-lactam derivatives.     

DABCO-Catalyzed Multicomponent Reaction for Synthesis of Benzo[a]carbazoles

DABCO (1,4-diazabicyclo[2.2.2]octane) catalyzed a multicomponent reaction using the starting precursor 2,3,4,9-tetrahydro-1H-carbazol-1-one, malononitrile, and aromatic/heteroaromatic aldehyde.     

DABCO-promoted three-component reaction between amines, dialkyl acetylenedicarboxylates, and glyoxal

A simple and efficient three-component protocol for the synthesis of highly substituted pyrroles has been developed by using amines, DEAD/DMAD, and glyoxal, with the formation of products in good to excellent yields.     

Conformation Analysis and Thermodynamics of Binding Behavior of DABCO to p/p type Dimeric Porphyrin Hosts

Covalently linked metalloporphyrin dimers have attracted considerably interest among chemists as models for metalloenzymes, which derive from their remarkable electron, energy transfer and special conformation properties1,2. Metalloporphyrins with large cavities have been designed and assembled with the idea of creating multisite complexing hosts incorporating functionalized subunits for binding organic substrates and transition metals so as to mimic metalloenzymes, as well as supermolecular ph…     

DABCO promoted one-pot synthesis of dihydropyrano(c)chromene and pyrano[2,3-d]pyrimidine derivatives and their biological activities

A simple and efficient one-pot synthesis of heteroaryl substititued dihydropyrano(c)chromenes and pyrano[2,3-d]pyrimidines has been developed via initial Knoevenagel, subsequent Micheal and final heterocyclization reactions of heteroaryl aldehyde, malononitrile and barbituric acid/ dimedone. 1,4-Diazabicyclo [2.2.2] octane (DABCO) has been used as a catalyst. Short reaction time, environment friendly procedure and excellent yields are the main advantages of this procedure. All synthesized compounds have shown good antimicrobial activity against different microbial stains.     

DABCO as a mild and efficient catalytic system for the synthesis of highly substituted imidazoles via multi-component condensation strategy

A simple and efficient protocol for the synthesis of highly substituted imidazoles is developed through the condensation of 1,2-dicarbonyl compound, aldehyde, and ammonium acetate or amine via multi-component condensation strategy. The present method gives good to excellent yields of substituted imidazoles.     

DABCO‐functionalized polysulfones as anion‐exchange membranes for fuel cell applications: Effect of crosslinking

A series of DABCO‐functionalized polysulfones were synthesized and characterized. The effect that crosslinking has on the membrane properties containing different degrees of functionalization was evaluated. These polymers showed good thermal stability below the fuel cell operation temperature, T < 100 °C, reflected by the T_OD, T_FD, and thermal durability. The water uptake increased as the percentage of DABCO groups increased and the crosslinked membranes showed lower capacity to absorb water than the non‐crosslinked ones favoring thus the dimensional stability of the first ones. Membranes in the chloride form containing low degree of functionalization exhibited the highest tensile strength values. The ionic conductivity of non‐crosslinked membranes varied as a function of the functionalization degree until a value of around 100% achieving a maximum value at 86%. However, the crosslinked ones showed satisfactory ionic conductivities for values higher than 100%. The behavior of these polymeric materials in alkaline solutions revealed a great alkaline stability necessary to be used as solid electrolytes in fuel cells. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1326–1336     

水杨酸功能化聚苯乙烯的制备及其与铕(Ⅲ)离子配合物荧光特性研究

以氯甲基聚苯乙烯(CMPS)为出发物质,通过两步改性反应,相转移催化的酯化反应(乙醛酸钠为反应试剂)与均相的Schiff碱反应,制备了侧链键合水杨酸(ASA)配基的聚苯乙烯ASAPS,并使之与Eu(Ⅲ)离子配位螯合,制备了高分子-稀土配合物ASAPS-Eu(Ⅲ).重点研究了相转移催化的酯化反应,也初步考察了配合物ASAPS-Eu(Ⅲ)的发光性能.研究结果表明,在季铵盐相转移催化剂作用下,溶解于有机溶剂中的CMPS可有效地与水相中的乙醛酸钠发生酯化反应,形成醛基(AL)化改性的聚苯乙烯ALPS.相转移催化剂的结构与溶剂的极性对相转移催化反应有显著的影响;配合物ASAPS-Eu(Ⅲ)具有Eu(Ⅲ)的特征荧光发射,并产生显著的Antenna效应.     

DABCO-catalyzed formation of 4-methoxy-1,3-dioxolan-2-ones and their synthetic applications in the aromatic electrophilic substitution

DABCO is a very effective catalyst in the formation of 4-methoxy-1,3-dioxolan-2-ones 10 from the corresponding α-carbonatoaldehydes 8 intermediates. The Friedel-Crafts reaction pathway of the cyclic carbonate 10 is dependent on the electron density of the aromatic nucleophiles.