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The efficient conversion of aryl halides to phenols under mild reaction conditions remains a grand challenge. Here we demonstrate that a facile and efficient hydroxylation reaction of aryl halides with...

The proximity of different active sites in multicatalytic systems is crucial in influencing the catalytic reactions, that is, to occur or to be accelerated. Here, we reported a heterogeneous metallaphotocatalyst prepared by embedding Ni(II) species in a photosensitive covalent organic framework (COF). A concerted triad catalytic behavior executed by electrons, holes, and Ni species triggered a dramatic catalytic enhancement in the activation of aryl chlorides with water to phenols. It demonstrated a 50-fold increment in its activity when compared to the homogeneous analogy, for example, Ni(BPDA)Br 2 . Also, it was able to efficiently activate a variety of aryl chlorides to the corresponding phenols with moderate to high yields. Interestingly, it was effective even for base-sensitive substituents or chlorobenzene bearing NH or NH 2 groups. On the basis of the detailed experiments, the proximity of the photoactive COF and Ni(II) sites facilitates rapid electron transfer to produce Ni(I) active sites for the oxidative addition. Meanwhile, the photogenerated holes oxidized water to the hydroxyl radical, which then attacked Ni(III) intermediates to complete the catalytic cycle.

A novel oral drug delivery system, TPGS modified docetaxel proniosomes (DTX-TPGS-PNs), was designed to enhance the oral bioavailability and antitumor efficiency of the poorly water-soluble drug docetaxel. DTX-TPGS-PN niosomes were 93 ± 6.5 nm in size, −18.53 ± 1.65 mV in zeta potential and exhibited spherical morphology, with an encapsulation efficiency of 97.31 ± 0.60%. The system showed sustained release in both simulated gastric and intestinal fluid. The results of caco-2 monolayer, everted gut sac model and improved single-pass intestinal perfusion model transport studies showed that DTX-TPGS-PN niosomes could significantly improve the absorption of DTX. The pharmacokinetics study suggested the absolute bioavailability of DTX-TPGS-PN niosomes were 7.3 times that of DTX solution. In addition, a higher antitumor efficacy than DTX solution was demonstrated in MCF-7 and MDA-MB-231 cells in vitro and in MCF-7 tumor-bearing mice model in vivo. Our results demonstrated DTX-TPGS-PN is promising in enhancing the bioavailability and efficiency of poorly water-soluble drug DTX, and the potential of proniosomes as stable precursors for oral drug delivery.

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