The cross-dimerization of terminal alkynes is the most straightforward and attractive approach to differently substituted 1,3-enynes,which are vital structural motifs in natural products,biologically active compounds,...The cross-dimerization of terminal alkynes is the most straightforward and attractive approach to differently substituted 1,3-enynes,which are vital structural motifs in natural products,biologically active compounds,and organic functional materials,etc.However,due to the inherent issues of the stereo-,regio-,and chemoselectivity,the strategy is less explored and remains problematic in substrate scope,selectivity,and screening of catalytic system,etc.Herein,a specific cross-dimerization of terminal alkynes is developed under Pd/TMEDA catalysis,which produces a series of gem-1,3-enynes(58 examples)in totally moderate to high yields with outstanding functional group tolerance.A cyclopalladium compound might be the key imtermediate,which performs anti-addition-carbometallation,and leads to the exclusive cross-selectivity.The unprecedented features of the reaction,such as anti-addition-carbometallation,easy control of selectivity,wide range of the donor alkynes,and very simple catalytic conditions,allow it not only a facile and functionally diverse synthesis of 1,3-enynes,but also a substantial progress for the textbook reaction.展开更多
以Cu/Ni为主活性组分,γ-Al2O3球为载体,考察了Mn助剂对N,N-二甲基乙醇胺(DMEA)固定床连续催化胺化制备N,N,N',N'-四甲基乙二胺(TMEDA)催化剂性能的影响,并通过XRD、BET/BJH、H2-TPR、H2-TPD等对催化剂结构进行表征,结果表明,M...以Cu/Ni为主活性组分,γ-Al2O3球为载体,考察了Mn助剂对N,N-二甲基乙醇胺(DMEA)固定床连续催化胺化制备N,N,N',N'-四甲基乙二胺(TMEDA)催化剂性能的影响,并通过XRD、BET/BJH、H2-TPR、H2-TPD等对催化剂结构进行表征,结果表明,Mn能够抑制脱氢而促进加氢反应的发生,随着Mn含量的增加,选择性会提高,而活性相对会受到抑制,当n(Cu)∶n(Ni)∶n(Mn)=4∶1∶0.2时催化剂性能较佳。采用4Cu-1Ni-0.2Mn/γ-Al2O3球作为催化胺化催化剂,在反应温度为240℃,DMEA空速为0.15 h-1,胺醇摩尔比为1∶1,常压,氢速为30 m L/min时,DMEA转化率和TMEDA选择性分别达到92%和83%左右。展开更多
基金supported by the National Natural Science Foundation of China(21878072,21706058,22102062,21725602)the Hunan Provincial Natural Science Foundation of China(2020JJ2011)the China Postdoctoral Science Foundation(2019M662774).
文摘The cross-dimerization of terminal alkynes is the most straightforward and attractive approach to differently substituted 1,3-enynes,which are vital structural motifs in natural products,biologically active compounds,and organic functional materials,etc.However,due to the inherent issues of the stereo-,regio-,and chemoselectivity,the strategy is less explored and remains problematic in substrate scope,selectivity,and screening of catalytic system,etc.Herein,a specific cross-dimerization of terminal alkynes is developed under Pd/TMEDA catalysis,which produces a series of gem-1,3-enynes(58 examples)in totally moderate to high yields with outstanding functional group tolerance.A cyclopalladium compound might be the key imtermediate,which performs anti-addition-carbometallation,and leads to the exclusive cross-selectivity.The unprecedented features of the reaction,such as anti-addition-carbometallation,easy control of selectivity,wide range of the donor alkynes,and very simple catalytic conditions,allow it not only a facile and functionally diverse synthesis of 1,3-enynes,but also a substantial progress for the textbook reaction.
文摘以Cu/Ni为主活性组分,γ-Al2O3球为载体,考察了Mn助剂对N,N-二甲基乙醇胺(DMEA)固定床连续催化胺化制备N,N,N',N'-四甲基乙二胺(TMEDA)催化剂性能的影响,并通过XRD、BET/BJH、H2-TPR、H2-TPD等对催化剂结构进行表征,结果表明,Mn能够抑制脱氢而促进加氢反应的发生,随着Mn含量的增加,选择性会提高,而活性相对会受到抑制,当n(Cu)∶n(Ni)∶n(Mn)=4∶1∶0.2时催化剂性能较佳。采用4Cu-1Ni-0.2Mn/γ-Al2O3球作为催化胺化催化剂,在反应温度为240℃,DMEA空速为0.15 h-1,胺醇摩尔比为1∶1,常压,氢速为30 m L/min时,DMEA转化率和TMEDA选择性分别达到92%和83%左右。
