Organic Nanoparticles Based on D-A-D Small Molecule: Self-Assembly, Photophysical Properties, and Synergistic Photodynamic/Photothermal Effects

Cancer is one of the major diseases threatening human health. Traditional cancer treatments have notable side-effects as they can damage the immune system. Recently, phototherapy, as a potential strategy for clinical cancer therapy, has received wide attention due to its minimal invasiveness and high efficiency. Herein, a small organic molecule (PTA) with a D-A-D structure was prepared via a Sonogashira coupling reaction between the electron-withdrawing dibromo-perylenediimide and electron-donating 4-ethynyl-N,N-diphenylaniline. The amphiphilic organic molecule was then transformed into nanoparticles (PTA-NPs) through the self-assembling method. Upon laser irradiation at 635 nm, PTA-NPs displayed a high photothermal conversion efficiency (PCE = 43%) together with efficient reactive oxygen species (ROS) generation. The fluorescence images also indicated the production of ROS in cancer cells with PTA-NPs. In addition, the biocompatibility and photocytotoxicity of PTA-NPs were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and live/dead cell co-staining test. Therefore, the as-prepared organic nanomaterials were demonstrated as promising nanomaterials for cancer phototherapy in the clinic.

Microwave-assisted, Copper-free Sonogashira Coupling between Aryl Halides and Terminal Alkynes Using Recyclable Ionic Liquid and Catalyst.

: An efficient method for the Sonogashira coupling reaction between aryl halides and terminal alkynes has been developed. The reaction was performed in ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) under microwave irradiation. High yields of products were obtained in very short reaction time. Moreover, the medium and catalyst could be recovered and reused three times without considerable decrease in reaction yields.

Functionalized Homologues and Positional Isomers of Rabbit 15-Lipoxygenase RS75091 Inhibitor

Background: RS75091 is a cinnamic acid derivative that has been used for the crystallization of the rabbit ALOX15-inhibitor complex. The atomic coordinates of the resolved ALOX15-inhibitor complex were later used to define the binding sites of other mammalian lipoxygenase orthologs, for which no direct structural data with ligand has been reported so far. Introduction: The putative binding pocket of the human ALOX5 was reconstructed on the basis of its structural alignment with rabbit ALOX15-RS75091 inhibitor. However, considering the possible conformational changes the enzyme may undergo in solution, it remains unclear whether the existing models adequately mirror the architecture of the ALOX5 active site. Methods: In this study, we prepared a series of RS75091 derivatives using a Sonogashira coupling reaction of regioisomeric bromocinnamates with protected acetylenic alcohols and tested their inhibitory properties on rabbit ALOX15 Results: A bulky pentafluorophenyl moiety linked to either ortho- or metha-ethynylcinnamates via aliphatic spacer does not significantly impair the inhibitory properties of RS75091. Conclusion: Hydroxylated 2- and 3-alkynylcinnamates may be suitable candidates for incorporation of an aromatic linker group like tetrafluorophenylazides for photoaffinity labeling assays.

Simple synthesis of poly (1,4-bis(dodecyloxy)-2,5-diethynylbenzene)/Pd composites with catalytic activity in Sonogashira coupling reaction

Palladium on the polymeric materials (Pd@polymer) as a catalyst is now very promising due to its great prospect for catalytic application. Such material in the form of composites is found to be stable and can be applied as catalyst in organic synthesis like Sonogashira coupling reaction. In the present work, Pd containing conjugated poly-ynes composites (Poly (1,4-bis(dodecyloxy)-2,5-diethynylbenzene) (Poly-DEB)/Pd) were synthesized by varying the addition of Pd in the range of equivalent weight of 8:4, 8:2 and 8:1, maintaining the fixed amount of 1,4-bis(dodecyloxy)-2,5-diethynylbenzene (DEB) through chemical oxidative polymerization technique. Both FTIR and UV-visible spectroscopy confirmed the interactions between DEB and Pd in the composites. The DSC data revealed the improved melting temperature as well as the crystallinity of the composites than the DEB. The PL spectra showed its florescence property. The catalytic capability of the Poly-DEB/Pd composites were examined using the Sonogashira coupling reactions, which demonstrated good yields. The suggested synthetic protocol is very facile, reproducible and beneficial for the fabrication of diverse mono and bimetallic composites with conjugated polymers. The present study also demonstrates the new example of Poly-DEB/Pd composites catalyzed Sonogashira coupling reaction. These composites have a possibility to develop as a commercial reagent in various organic synthesis subjects to its application prospects.

Synthesis of Multibromo-Substituted Quinolines by NBS-Mediated Cascade Electrophilic Bromination/Cyclization of N-(3-Phenylprop-2-ynyl)anilines

A new and convenient protocol is presented here for the synthesis of 3,6,8-tribromoquinolines via cascade cyclization of N-(3-phenylprop-2-ynyl)anilines employing N-bromosuccinimide as an electrophile. The metal-free process is carried out under mild conditions and is compatible with a variety of substituents. The Sonogashira coupling reaction regioselectively occurs at position C-6 of the obtained products.

Palladium Catalyzed Synthesis of Phenylquinoxaline-Alkyne Derivatives via Sonogashira Cross Coupling Reaction

Transition metals mediated cross coupling methodologies provide an extremely powerful versatile pathway in organic syntheses undoubtedly, a facile route for syntheses and derivatization of biologically important heterocycles from easily available precursors. Sonogashira coupling reaction, a leading method to Csp-Csp2 bond formation is one of the most important and rapid pathways to couple aryl/vinyl halides with terminal alkynes. Current research study deals with the synthesis of alkyne substituted quinoxaline derivatives. The quinoxalines class of aromatic heterocycles exhibits a wide variety of important biological potencies. Palladium catalyzed cross coupling process provided an effective synthetic practice for the synthesis of alkyne derivatives of quinoxaline. Vareity of terminal alkynes were coupled with 2-(4-bromophenyl)quinoxaline under optimized conditions for Sonogashira reaction, affording alkyne substituted quinoxaline derivatives in high yields. The optimized reaction conditions for coupling of range of terminal alkyne with quinoxaline basic core render this process significant for designing of medicinally interesting precursors.