Stereoselective Michael addition and Michael-aldol tandem reaction of diorganyl diselenides and disulfides with conjugated alkynones mediated by samarium diiodide were studied. The reaction temperature was critical fo...Stereoselective Michael addition and Michael-aldol tandem reaction of diorganyl diselenides and disulfides with conjugated alkynones mediated by samarium diiodide were studied. The reaction temperature was critical for the stereoselectivity. -Organylselenoalkenones or -organylthioalkenones and ?-organylselenoallylic alcohols or ?-organylthioallylic alcohols were prepared in good yields.展开更多
Under N\-2 atmosphere and at room temperature, the reaction of diaryl diselenid（1\^0 mmol） with terminal alkynes（2\^2 mmol） catalyzed by cesium hydroxy gave exclusively （Z）-1,2-bis（arylseleno）-1-alkenes, but u...Under N\-2 atmosphere and at room temperature, the reaction of diaryl diselenid（1\^0 mmol） with terminal alkynes（2\^2 mmol） catalyzed by cesium hydroxy gave exclusively （Z）-1,2-bis（arylseleno）-1-alkenes, but under air and at -100 ℃, the reaction gave alkyne selenides in 83%95% yields based on the selenium atoms. The method for the preparation of alkyne selenides has advantages of available starting materials and simple procedures. The reaction mechanism was proposed.展开更多
Hydrogels crosslinked by dynamic covalent bonds can effectively mimic the viscoelastic properties of native extracellular matrix and have been widely explored for 3D cell culture.Disulfide is one of the most common dy...Hydrogels crosslinked by dynamic covalent bonds can effectively mimic the viscoelastic properties of native extracellular matrix and have been widely explored for 3D cell culture.Disulfide is one of the most common dynamic bonds in biological systems whose formation and cleavage are catalyzed by a set of dedicated enzymes.However,in vitro formation of disulfide bonds is a slow process and requires harsh catalysts.Therefore,it is difficult to use disulfide crosslinked hydrogels for cell culture.n this work,we show that disulfide bonds can be formed by thiol-diselenide(Dise)exchange under blue light llumination.This reaction is fast,reversible,and biocompatible.Moreover,residual diselenide in the hydrogel network can also accelerate thiol-disulfide exchange reactions leading to faster cell release from the hydrogels upon the addition of thiol-containing agents.We anticipate that disulfide crosslinked hydrogels catalyzed by diselenide can find broad biomedical applications,such as cell culture,celldelivery,and drug-controlled release.展开更多
在铁粉存在下,以商用N,N-二甲基甲酰胺(DMF)作溶剂,90℃、氮气保护下,二芳基二硒醚与α-溴代羰基化合物反应,得到一系列α-芳硒基羰基化合物.考察了温度、时间、溶剂及铁粉用量对反应的影响,其中,温度对反应的影响最为明显.α-溴代羰基...在铁粉存在下,以商用N,N-二甲基甲酰胺(DMF)作溶剂,90℃、氮气保护下,二芳基二硒醚与α-溴代羰基化合物反应,得到一系列α-芳硒基羰基化合物.考察了温度、时间、溶剂及铁粉用量对反应的影响,其中,温度对反应的影响最为明显.α-溴代羰基化合物中羰基上取代基对反应有很大影响,取代基为苯基时,转化率较甲基或烷氧基时低.反应机理可能是铁插入Se—Se键中形成亲核性Se Fe Se,随后与亲电底物α-溴代羰基化合物发生亲核取代.本方法使用铁粉促进断裂Se—Se键具有原料安全无毒、廉价易得、实验操作简便等优点.展开更多
基金the National Natural Science Foundation of China (No. 20072033) and the Specialized Research Fund for the Doctoral Program of Higher Education of China.
文摘Stereoselective Michael addition and Michael-aldol tandem reaction of diorganyl diselenides and disulfides with conjugated alkynones mediated by samarium diiodide were studied. The reaction temperature was critical for the stereoselectivity. -Organylselenoalkenones or -organylthioalkenones and ?-organylselenoallylic alcohols or ?-organylthioallylic alcohols were prepared in good yields.
文摘Under N\-2 atmosphere and at room temperature, the reaction of diaryl diselenid（1\^0 mmol） with terminal alkynes（2\^2 mmol） catalyzed by cesium hydroxy gave exclusively （Z）-1,2-bis（arylseleno）-1-alkenes, but under air and at -100 ℃, the reaction gave alkyne selenides in 83%95% yields based on the selenium atoms. The method for the preparation of alkyne selenides has advantages of available starting materials and simple procedures. The reaction mechanism was proposed.
基金This work is funded by the National Key R&D Program of China(Grant No.2020YFA0908100)the National Natural Science Foundation of China(Nos.11934008,11974174 and 12002149)the Research Project of Jinan Microecological Biomedicine Shandong Laboratory。
文摘Hydrogels crosslinked by dynamic covalent bonds can effectively mimic the viscoelastic properties of native extracellular matrix and have been widely explored for 3D cell culture.Disulfide is one of the most common dynamic bonds in biological systems whose formation and cleavage are catalyzed by a set of dedicated enzymes.However,in vitro formation of disulfide bonds is a slow process and requires harsh catalysts.Therefore,it is difficult to use disulfide crosslinked hydrogels for cell culture.n this work,we show that disulfide bonds can be formed by thiol-diselenide(Dise)exchange under blue light llumination.This reaction is fast,reversible,and biocompatible.Moreover,residual diselenide in the hydrogel network can also accelerate thiol-disulfide exchange reactions leading to faster cell release from the hydrogels upon the addition of thiol-containing agents.We anticipate that disulfide crosslinked hydrogels catalyzed by diselenide can find broad biomedical applications,such as cell culture,celldelivery,and drug-controlled release.
文摘在铁粉存在下,以商用N,N-二甲基甲酰胺(DMF)作溶剂,90℃、氮气保护下,二芳基二硒醚与α-溴代羰基化合物反应,得到一系列α-芳硒基羰基化合物.考察了温度、时间、溶剂及铁粉用量对反应的影响,其中,温度对反应的影响最为明显.α-溴代羰基化合物中羰基上取代基对反应有很大影响,取代基为苯基时,转化率较甲基或烷氧基时低.反应机理可能是铁插入Se—Se键中形成亲核性Se Fe Se,随后与亲电底物α-溴代羰基化合物发生亲核取代.本方法使用铁粉促进断裂Se—Se键具有原料安全无毒、廉价易得、实验操作简便等优点.
