Potassium tert-butoxide has been found to be a highly efficient catalyst for one-pot,three-component reaction of aryl aldehydes, acetophenones,and thiols via Claisen-Schmidt/Michael addition reactions for the synthesi...Potassium tert-butoxide has been found to be a highly efficient catalyst for one-pot,three-component reaction of aryl aldehydes, acetophenones,and thiols via Claisen-Schmidt/Michael addition reactions for the synthesis of thia-Michael adducts in high yields. The reactions are best carried out in tert-butyl alcohol at room temperature.展开更多
以乙腈作溶剂,苄基溴和二苯胺在叔丁醇钾的催化下,可以直接合成得到N,N-二苯基苄叔胺类化合物,产率60.2%~81.4%。产物经1 H NMR、13 C NMR和GC-MS确证。得出合成N,N-二苯基叔胺最优化条件为n（苄基溴）∶n（二苯胺）∶n（叔丁醇钾）=1.5...以乙腈作溶剂,苄基溴和二苯胺在叔丁醇钾的催化下,可以直接合成得到N,N-二苯基苄叔胺类化合物,产率60.2%~81.4%。产物经1 H NMR、13 C NMR和GC-MS确证。得出合成N,N-二苯基叔胺最优化条件为n（苄基溴）∶n（二苯胺）∶n（叔丁醇钾）=1.5∶1∶1,以乙腈为溶剂,室温下反应12h。该方法具有反应条件温和,操作简单,产率较高等优点。展开更多
A simple and efficient methodology for Markovnikov addition of azoles with vinyl acetate catalyzed by potassium tert-butoxide is described.N-heterocyclic compounds are synthesized from simple and commercially availabl...A simple and efficient methodology for Markovnikov addition of azoles with vinyl acetate catalyzed by potassium tert-butoxide is described.N-heterocyclic compounds are synthesized from simple and commercially available starting materials under mild conditions in high yields.展开更多
Coupling reactions between haloarenes and arenes(including heteroarenes)that are conducted without added transition metals but in the presence of KOtBu or NaOtBu,have been a topic of great interest since their discove...Coupling reactions between haloarenes and arenes(including heteroarenes)that are conducted without added transition metals but in the presence of KOtBu or NaOtBu,have been a topic of great interest since their discovery in 2008.Diverse organic structures act as additives that assist these reactions.These additives are converted into organic electron donors by the butoxide base and this leads to initiation of the coupling reactions,which proceed by radical chain mechanisms.This review provides an overview of the initiation stages of these reactions.展开更多
It still remains a concern to break through the bottlenecks of anionic polymerization of polar monomers, such as side reactions, low conver- sion and low temperature （-78 ℃）. In this work, potassium tert-butoxide ...It still remains a concern to break through the bottlenecks of anionic polymerization of polar monomers, such as side reactions, low conver- sion and low temperature （-78 ℃）. In this work, potassium tert-butoxide （t-BuOK） was chosen to initiate the anionic polymerization of 2-ethylhexyl methacrylate （EHMA） in tetrahydrofuran. The conversions were above 99% at 0 or 30 ℃, and above 95% at 60 ℃ without side reaction inhibitors. The high conversions implied t-BuOK could suppress the side reactions. A series of block copolymers of EHMA, n-hexyl methacrylate （HMA） and methyl methacrylate （MMA） were further synthesized at 0 ℃, and the conversions were all above 99%. The GPC and IH NMR results confirmed the successful synthesis of the block copolymers. The molecular size of monomer and the state of t-BuOK （free ion pairs or aggregates） remarkably affected the polymerization rates and the molecular structures of the products. The DMA results indicated that the glass transition temperatures of PEHMA or PHMA block and PMMA block were 20 ℃ and 60 ℃, respectively, which deviated from -2 ℃ and 105 ℃ of homopolymer, respectively, due to the partial com- patibility of the blocks. This work explored a route of the anionic polymerization of polar monomers at room temperature.展开更多
文摘Potassium tert-butoxide has been found to be a highly efficient catalyst for one-pot,three-component reaction of aryl aldehydes, acetophenones,and thiols via Claisen-Schmidt/Michael addition reactions for the synthesis of thia-Michael adducts in high yields. The reactions are best carried out in tert-butyl alcohol at room temperature.
文摘以乙腈作溶剂,苄基溴和二苯胺在叔丁醇钾的催化下,可以直接合成得到N,N-二苯基苄叔胺类化合物,产率60.2%~81.4%。产物经1 H NMR、13 C NMR和GC-MS确证。得出合成N,N-二苯基叔胺最优化条件为n（苄基溴）∶n（二苯胺）∶n（叔丁醇钾）=1.5∶1∶1,以乙腈为溶剂,室温下反应12h。该方法具有反应条件温和,操作简单,产率较高等优点。
文摘A simple and efficient methodology for Markovnikov addition of azoles with vinyl acetate catalyzed by potassium tert-butoxide is described.N-heterocyclic compounds are synthesized from simple and commercially available starting materials under mild conditions in high yields.
基金EPSRCGSKthe University of Strathclyde for funding(AJS)
文摘Coupling reactions between haloarenes and arenes(including heteroarenes)that are conducted without added transition metals but in the presence of KOtBu or NaOtBu,have been a topic of great interest since their discovery in 2008.Diverse organic structures act as additives that assist these reactions.These additives are converted into organic electron donors by the butoxide base and this leads to initiation of the coupling reactions,which proceed by radical chain mechanisms.This review provides an overview of the initiation stages of these reactions.
基金The authors are grateful for the financial support from the National Natural Science Foundation of China （Nos. 50933002, 51373052, 51573043）.
文摘It still remains a concern to break through the bottlenecks of anionic polymerization of polar monomers, such as side reactions, low conver- sion and low temperature （-78 ℃）. In this work, potassium tert-butoxide （t-BuOK） was chosen to initiate the anionic polymerization of 2-ethylhexyl methacrylate （EHMA） in tetrahydrofuran. The conversions were above 99% at 0 or 30 ℃, and above 95% at 60 ℃ without side reaction inhibitors. The high conversions implied t-BuOK could suppress the side reactions. A series of block copolymers of EHMA, n-hexyl methacrylate （HMA） and methyl methacrylate （MMA） were further synthesized at 0 ℃, and the conversions were all above 99%. The GPC and IH NMR results confirmed the successful synthesis of the block copolymers. The molecular size of monomer and the state of t-BuOK （free ion pairs or aggregates） remarkably affected the polymerization rates and the molecular structures of the products. The DMA results indicated that the glass transition temperatures of PEHMA or PHMA block and PMMA block were 20 ℃ and 60 ℃, respectively, which deviated from -2 ℃ and 105 ℃ of homopolymer, respectively, due to the partial com- patibility of the blocks. This work explored a route of the anionic polymerization of polar monomers at room temperature.
