Browsing by Author "Wang, Mian"

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    Copper-catalyzed diastereoselective aerobic intramolecular dehydrogenative coupling of hydrazones via sp3 C–H functionalization
    (Royal Society of Chemistry, 2015) Wu, Xuesong; Wang, Mian; Zhang, Guangwu; Zhao, Yan; Wang, Jianyi; Ge, Haibo; Department of Chemistry & Chemical Biology, School of Science
    Transition metal-catalyzed cross dehydrogenative coupling is an important tool for functionalization of the α Csp3–H bond of amines. Among this reaction category, copper-catalyzed selective C–C bond formation under atmospheric O2 is of considerable research interest and significant progress has been achieved in recent years. In comparison, development of the intramolecular version of this transformation is still in its infancy. Furthermore, diastereoselective cyclization with this transformation has not been achieved. Here, we describe the highly diastereoselective intramolecular dehydrogenative cyclization of N,N-disubstituted hydrazones by a copper-catalyzed sp3 C–H bond functionalization process. The reaction protocol utilizes O2 as the oxidant and shows great functional group compatibility. Computational studies suggest that a 5-center/6-electron disrotatory cyclization mechanism is probably involved in the process for controlling the diastereoselectivity. This work represents the first example of a copper-catalyzed, direct intramolecular diastereoselective coupling reaction via an iminium ion intermediate. Additionally, it provides an environmentally friendly and atom efficient approach to access substituted pyrazolines, an important structural unit in many biologically active compounds.
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    Dual hepatocyte-targeting fluorescent probe with high sensitivity to tumorous pH: Precise detection of hepatocellular carcinoma cells
    (Elsevier, 2019-04) Zhang, Yamin; Li, Zhenjie; Ge, Haibo; Zhu, Xueyan; Zhao, Zhuang; Qi, Zhong-quan; Wang, Mian; Wang, Jianyi; Chemistry and Chemical Biology, School of Science
    A new dual hepatocyte-targeting fluorescent probe HPL-1, which can precisely distinguish tumorous pH from physiological pH, was developed. The OFF-ON switch of HPL-1 can be triggered via pH-induced structural change of the lactam group of the rhodamine moiety from closed-ring to open-ring. Our results showed that the phosphate group of HPL-1 is beneficial to its accumulation in liver cells, and combination of the phosphate and galactose units could synergistically increase the hepatocyte-targeting capacity. HPL-1 could selectively distinguish hepatoma cells from other tissue cells, and precisely distinguish cancerous liver cells from normal liver cells. Compared with other reported probes, HPL-1 not only enable a simple and convenient detection method, but also has good hepatocyte-targeting capacity and precise recognition capacity of tumors under weak acid micro-environment, which opens new avenues for precise diagnosis and treatment of hepatocellular carcinoma.