New Bicyclic Azalide Macrolides Obtained by Tandem Palladium Catalyzed Allylic Alkylation/Conjugated Addition Reaction

Unprecedented tandem allylic alkylation/intermolecular Michael addition was used in the preparation of novel bicyclic azalides. NMR spectroscopy was used not only to unambiguously determine and characterize the structures of these unexpected products of chemical reaction but also to investigate the effect the rigid bicyclic modification has on the conformation of the whole molecule. Thus, some of the macrolides prepared showed antibacterial activity in the range of well-known antibiotic drug azithromycin.

Investigation of microflow reactor diameter on condensation reactions in L-proline-immobilized polymer monoliths

The effect of monolith structure and monolith reactor inner diameter on residence time distribution (RTD), and the relationship between RTD and the catalytic efficiency of the asymmetric aldol addition reaction...

Ultrasound-assisted synthesis of β-enaminone derivatives via Tin(Ⅳ)-catalyzed addition reaction from β-dicarbonyl compounds with nitriles

An efficient and eco-friendly approach for the synthesis of β-enaminone derivatives is described, which is through the addition of nitriles with β-dicarbonyl compounds under ultrasound irradiation condition at room temperature. The scope and limitation of this strategy are also discussed. A variety of substituted amides can be obtained in moderate to good yields. We hope that this protocol for the efficient synthesis of β-enaminones will offer insights in further investigations.

Reaction Mechanism About Isomerization of Resin Acids and Synthesis of Acrylopimaric Acid Based on DFT Calculation

Acrylopimaric acid is considered one of the possible substitutes for petroleum-based polymeric monomers, which is an important industrial product. Resin acids were isomerized to form levopimaric acid(4), which reacted with acrylic acid to synthesize isomers of acrylopimaric acid. Density functional theory calculation was used to investigate the reaction mechanisms with seven reaction paths in five different solutions. The values of ΔG were sorted from highest to lowest by levopimaric acid(4), neoabietic acid(3), palustric acid(2), and bietic acid(1). From the perspective of dynamics, the energy barrier in the isomerization of palustric acid(2) to levopimaric acid(4) was the lowest, whereas the highest energy barrier was the isomerization of neoabietic acid(3) to levopimaric acid(4) in the same solution. The addition reaction of levopimaric acid(4) and acrylic acid(5) to acrylopimaric acid c(8) was the optimal reaction path dynamically. However, ΔG of acrylopimaric acid c(8) was higher than that of acrylopimaric acid d(9). In general, the rates of isomerization reactions for rosin resin acids and addition reaction for acrylopimaric acid in water were higher than those in other solvents. HOMO-LUMO and ESP were analyzed for 8 kinds of molecules. For acylpyimaric acid, the non-planar six-memed ring and the C-C double bonds were easily attacked by nucleophile, while the non-planar six-memed ring and the carboxyl group are easily reacted with electrophiles. The highest electrostatic potential of the eight molecules is located at H of the carboxyl group, while the highest electrostatic potential is located at C-O double bond of the carboxyl group.

Copper-Catalyzed Ring-Opening Reactions of Alkyl Aziridines with B2pin2: Experimental and Computational Studies

The possibility to form new C–B bonds with aziridines using diboron derivatives continues to be a particularly challenging field in view of the direct preparation of functionalized β-aminoboronates, which are important compounds in drug discovery, being a bioisostere of β-aminoacids. We now report experimental and computational data that allows the individuation of the structural requisites and of reaction conditions necessary to open alkyl aziridines using bis(pinacolate)diboron (B2pin2) in a regioselective nucleophilic addition reaction under copper catalysis.

Synthesis and Antimalarial Activity of 7-Chloro-4-(4-(2-(Oxo, Hydroxyl & Fluoro-2-1 (4-Phenyl)Ethyl)Piperazin-1-yl)Quinoline Derivatives

Since these days, microbes are resistant to the drugs available in the market, which has caused an alarming impact on society. 18 compounds in a series of 7-chloro-4-(piperazin-1-yl)quinoline derivatives were synthesized by nucleophilic addition reaction of piperazine with 4,7-dichloroquinoline followed by phenacyl bromides addition to heteroaryl piperazine and then reduction and fluorination. All 18 compounds were evaluated in vitro for their antimalarial activity against plasmodium falciparum strain. Although 12 compounds showed good activity, compound 3c was found to be more potent than standard drug Quinine having MIC 0.18 μg/ mL. On the other hand, 3d, 3e, 5a, and 5f were found to be equipotent (MIC 0.26 μg/ mL) to the standard drug.