7 research outputs found

    Pd-Catalyzed Regiodivergent Hydroesterification of Aryl Olefins with Phenyl Formate

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    An effective Pd-catalyzed regiodivergent hydroesterification of aryl olefins with phenyl formate is described. Either linear or branched phenyl arylpropanoates can be obtained in good yields with high regioselectivities by the judicious choice of ligand without the use of toxic CO gas

    Palladium-Catalyzed Highly Regio- and Enantioselective Hydroesterification of Aryl Olefins with Phenyl Formate

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    An effective Pd-catalyzed regio- and enantioselective hydroesterification of aryl olefins with phenyl formate is described. A variety of phenyl 2-arylpropanoates can be obtained in good yields with high b/l ratios and ee’s without using toxic CO gas

    Triphenylphosphine‑<i>m</i>‑sulfonate/Carbon Tetrabromide as an Efficient and Easily Recoverable Catalyst System for Friedel–Crafts Alkylation of Indoles with Carbonyl Compounds or Acetals

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    A solid complex, conveniently prepared from commercially available sodium triphenylphosphine-<i>m</i>-sulfonate (TPPMS) and carbon tetrabromide, can be used as an easily recoverable and reusable catalyst system for Friedel–Crafts alkylation of indoles with carbonyl compounds or acetals to produce bis­(indolyl)­alkane products (BIAs)

    An Effective Pd-Catalyzed Regioselective Hydroformylation of Olefins with Formic Acid

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    An effective palladium-catalyzed regioselective hydroformylation of olefins with formic acid is described. The ligand plays a crucial role in directing the reaction pathway. Linear aldehydes can be obtained in up to 93% yield with >20:1 regioselectivity using 1,3-bis­(diphenylphosphino)­propane (dppp) as the ligand. The reaction process is operationally simple and requires no syngas

    Imaging Tiny Hepatic Tumor Xenografts via Endoglin-Targeted Paramagnetic/Optical Nanoprobe

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    Surgery is the mainstay for treating hepatocellular carcinoma (HCC). However, it is a great challenge for surgeons to identify HCC in its early developmental stage. The diagnostic sensitivity for a tiny HCC with a diameter less than 1.0 cm is usually as low as 10–33% for computed tomography (CT) and 29–43% for magnetic resonance imaging (MRI). Although MRI is the preferred imaging modality for detecting HCC, with its unparalleled spatial resolution for soft tissue, the commercially available contrast agent, such as Gd<sup>3+</sup>-DTPA, cannot accurately define HCC because of its short circulation lifetime and lack of tumor-targeting specificity. Endoglin (CD105), a type I membrane glycoprotein, is highly expressed both in HCC cells and in the endothelial cells of neovasculature, which are abundant at the tumor periphery. In this work, a novel single-stranded DNA oligonucleotide-based aptamer was screened by systematic evolution of ligands in an exponential enrichment assay and showed a high binding affinity (<i>K</i><sub>D</sub> = 98 pmol/L) to endoglin. Conjugating the aptamers and imaging reporters on a G5 dendrimer created an HCC-targeting nanoprobe that allowed the successful visualization of orthotopic HCC xenografts with diameters as small as 1–4 mm. Significantly, the invasive tumor margin was clearly delineated, with a tumor to normal ratio of 2.7 by near-infrared (NIR) fluorescence imaging and 2.1 by <i>T</i><sub>1</sub>-weighted MRI. This multimodal nanoprobe holds promise not only for noninvasively defining tiny HCC by preoperative MRI but also for guiding tumor excision via intraoperative NIR fluorescence imaging, which will probably gain benefit for the patient’s therapeutic response and improve the survival rate
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