Shengchen Lv,Peng Wang,Donghui Liu,Xueke Liu,Zhiqiang Zhou,Peng Wang
To set up effective analysis method is important for environmental monitoring. In this work, the 4-aminophenol functionalized nitrogen and sulfur co-doped carbon quantum dots (AP-NSCDs) were synthesized based on the functionalization of NSCDs obtained by one-step hydrothermal method and used as a new fluorescent sensor for the determination of nitroalkene pesticide and medicine, such as nitenpyram, nizatidine and ranitidine. Nitroalkenes could quench the fluorescence of the functionalized carbon dots due to the fluorescence resonance energy transfer (FRET) principle. The sensor showed high sensitivity, selectivity, and stability, with a wide linear range of 0.05 ∼ 10 mg/L and a low detection limit of 0.02 mg/L. This sensor was successfully employed to detect nitenpyram in rice, orange and cabbage, and to determine nizatidine and ranitidine in serum, urine and river water as well. The developed method was rapid and sensitive, and had potential for monitoring the nitroalkene compounds in the environment and food.
Yan-Qiu Deng,Zhen-Wei Zhang,Ya-Hui Feng,Albert S.C. Chan,Gui Lu
An effective asymmetric synthesis of optically active 1,3-dinitro compounds via the direct Michael addition of nitroalkanes onto nitroalkenes has been described. In the presence of readily modified cinchona alkaloid derivatives, nitroethane reacted well with a variety of aromatic and heterocyclic aromatic nitroalkenes to afford products with good diastereoselectivities (dr up to 72/28) and enantioselectivities (ee up to 94%). The catalyst loading can be decreased to 2 mol % without compromising the asymmetric induction or the reaction rate.
Tao Li,Weilin Wang,Songmeng Wang,Lingyan Liu,Weixing Chang,Jing Li
An amphiphilic block copolymer PNIPAM 53 - b -(PS 30 - co -P4AMS 10 ) was facilely prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization. The immobilization of ( S )-α,α-diphenylprolinol trimethylsilyl ether onto the block copolymers was then performed through using copper-catalyzed alkyne-azide cycloaddition (CuAAC), and the generating amphiphilic diblock copolymer supported chiral catalyst PNIPAM 53 - b -(PS 30 - co -P4AMS 10 )/proTMS was self-assembled into micelles with regular diameters about 50 nm in aqueous solution. The micellar catalyst was further used for the asymmetric Michael reaction between propanal and trans -β-nitrostyrene in water. Using only 1 mol% micellar catalyst, the corresponding Michael addition products could be obtained in good yields and high enantioselectivities as well as good diastereoselectivities. In addition, this micellar catalyst could be reused at least for four times. Moreover, the micellar catalyst could be applied for the asymmetric addition reaction of 4-chlorocinnamyl aldehyde and nitromethane, and thus constructing the baclofen pharmaceutical intermediate.
Junnan He,Nan Zheng,Ming Li,YuBin Zheng,Wangze Song
Multicomponent polymerization has emerged as a promising strategy to develop functional polymers with versatile structures. In this work, a Cu-catalyzed four-component polymerization was developed using diynes, sulfonyl azides, nucleophiles, and a variety of electrophiles including alkyl glyoxylates, nitroalkenes, and Morita–Baylis–Hillman adducts to successfully synthesize a library of α-functionalized poly(N-sulfonylimidates)s with a wide substrate scope and high molecular weights (up to 20 000 g mol−1) in high yields (up to 86%). Such α-functionalized poly(N-sulfonylimidates)s could be further post-modified or utilized for the design of multi-functional and biodegradable polymers.
危险品化学品经营许可证（带存储）