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Hangzhou, China

Shen C.,Hangzhou Normal University | Shen C.,Zhejiang Shuren University | Zhang P.,Hangzhou Normal University | Sun Q.,National University of Singapore | And 5 more authors.
Chemical Society Reviews

The development of mild and general methods for C-S bond formation has received significant attention because the C-S bond is indispensable in many important biological and pharmaceutical compounds. Early examples for the synthesis of C-S bonds are generally limited to the condensation reaction between a metal thiolate and an organic halide. Recent chemical approaches for C-S bond formation, based upon direct C-H bond functionalization and decarboxylative reactions, not only provide new insights into the mechanistic understanding of C-S coupling reactions but also allow the synthesis of sulfur-containing compounds from more effective synthetic routes with high atom economy. This review intends to explore recent advances in C-S bond formation via C-H functionalization and decarboxylation, and the growing opportunities they present to the construction of complex chemical scaffolds for applications encompassing natural product synthesis, synthetic methodology development, and functional materials as well as nanotechnology. © The Royal Society of Chemistry 2015. Source

Shen C.,Zhejiang Shuren University | Shen C.,Hangzhou Normal University | Xu J.,Hangzhou Normal University | Yu W.,Hangzhou Normal University | Zhang P.,Hangzhou Normal University
Green Chemistry

Aryl sulfones were synthesized using a highly active and easily recoverable heterogeneous Cu catalyst which was prepared by simply stirring an aqueous suspension of chitosan in water with copper salts. The chitosan@copper catalyst catalyzed the coupling reactions of aryl halides with sodium sulfinates to readily give the corresponding sulfones in good to excellent yields. The highly active catalyst can be reused many times without losing its catalytic activity. In addition, by using this protocol, the marketed drug zolimidine (antiulcer) could be synthesized easily. This journal is © the Partner Organisations 2014. Source

Xu D.,Zhejiang Shuren University | Li C.,Zhejiang University | Wen Y.,Zhejiang University | Liu W.,Zhejiang University
Environmental Pollution

The use of earthworms as a sublethal endpoint has significantly contributed to the ecological risk assessment of contaminated soils. Few studies have focused on the potential toxicity of PFOS to earthworms in the soil. In this work, artificial soils were tested, and contact filter paper studies were used. The results showed that earthworm growth was generally inhibited. The antioxidant activities of the enzymes superoxide dismutase, peroxidase, catalase and glutathione peroxidase were initially activated and then inhibited. Reduced glutathione content was observed, and malondialdehyde content was elevated over the duration of the exposure. These results suggested that PFOS induced oxidative stress in earthworms. In addition, the values of olive tail moment, tail DNA% and tail length using SCGE showed similar frequency distributions and increased with increases in the PFOS concentration. These results suggest that all concentrations of PFOS cause DNA damage. © 2012 Elsevier Ltd. All rights reserved. Source

Zhou Z.-S.,Zhejiang Shuren University | He X.-H.,Zhejiang Institute of Geology
Tetrahedron Letters

A novel and convenient catalytic method for phosphoryloxylactonization of pentenoic acids is available: the cyclization of 4-pentenoic acids with phosphates using iodobenzene as a recyclable catalyst in combination with m-chloroperbenzoic acid as the terminal oxidant was easily carried out in CF3CH2OH at room temperature, giving phosphoryloxylactons in good yields, some of them had two diastereoisomers. © 2010 Elsevier Ltd. All rights reserved. Source

Hu F.,Zhejiang Shuren University
Journal of Sensors

For the problem of easily losing track target when obstacles appear in intelligent robot target tracking, this paper proposes a target tracking algorithm integrating reduced dimension optimal Kalman filtering algorithm based on phase-path volume integral with Camshift algorithm. After analyzing the defects of Camshift algorithm, compare the performance with the SIFT algorithm and Mean Shift algorithm, and Kalman filtering algorithm is used for fusion optimization aiming at the defects. Then aiming at the increasing amount of calculation in integrated algorithm, reduce dimension with the phase-path volume integral instead of the Gaussian integral in Kalman algorithm and reduce the number of sampling points in the filtering process without influencing the operational precision of the original algorithm. Finally set the target centroid position from the Camshift algorithm iteration as the observation value of the improved Kalman filtering algorithm to fix predictive value; thus to make optimal estimation of target centroid position and keep the target tracking so that the robot can understand the environmental scene and react in time correctly according to the changes. The experiments show that the improved algorithm proposed in this paper shows good performance in target tracking with obstructions and reduces the computational complexity of the algorithm through the dimension reduction. © 2016 Fengjun Hu. Source

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