以六硝基联卞(HNBB)为原料,4-羟基-2,2,6,6-四甲基哌啶-N-氧自由基(4-OH-TEMPO)和氯化亚铁(FeCl2)为催化剂,在二甲亚砜(DMSO)中通过氧气氧化HNBB脱氢制备了六硝基茋(HNS),收率为81%。确定了最佳反应条件:溶剂为DMSO,催化剂组合及其比例...以六硝基联卞(HNBB)为原料,4-羟基-2,2,6,6-四甲基哌啶-N-氧自由基(4-OH-TEMPO)和氯化亚铁(FeCl2)为催化剂,在二甲亚砜(DMSO)中通过氧气氧化HNBB脱氢制备了六硝基茋(HNS),收率为81%。确定了最佳反应条件:溶剂为DMSO,催化剂组合及其比例为n(4-OH-TEMPO)∶n(FeCl2)=4∶6时,在55℃下以25 m L·h-1的速率通入氧气反应8 h。推测了可能的反应机理:亚铁离子结合氧气直接氧化底物HNBB脱氢得到HNS,4-OH-TEMPO在这个过程中起到一个促进FeCl2循环加速氧化脱氢的助催化作用。展开更多
Transition-metal-catalyzed cross-coupling reactions as very efficient and atom-economical approaches have been widely used to build up complex heterocyclic compounds.However,modification of 2-oxyl benzimidazole skelet...Transition-metal-catalyzed cross-coupling reactions as very efficient and atom-economical approaches have been widely used to build up complex heterocyclic compounds.However,modification of 2-oxyl benzimidazole skeleton using maleimide compounds via C–H activation has remained unprecedented.Herein,we developed a rhodium(III)-catalyzed[5+1]cascade spiroannulation to construct diversified novel benzimidazole-incorporated spirosuccinimide derivatives from 2-oxyl benzimidazoles and maleimides.展开更多
文摘以六硝基联卞(HNBB)为原料,4-羟基-2,2,6,6-四甲基哌啶-N-氧自由基(4-OH-TEMPO)和氯化亚铁(FeCl2)为催化剂,在二甲亚砜(DMSO)中通过氧气氧化HNBB脱氢制备了六硝基茋(HNS),收率为81%。确定了最佳反应条件:溶剂为DMSO,催化剂组合及其比例为n(4-OH-TEMPO)∶n(FeCl2)=4∶6时,在55℃下以25 m L·h-1的速率通入氧气反应8 h。推测了可能的反应机理:亚铁离子结合氧气直接氧化底物HNBB脱氢得到HNS,4-OH-TEMPO在这个过程中起到一个促进FeCl2循环加速氧化脱氢的助催化作用。
基金We are grateful for the financial support from 111 Project(No.B18035)and“the Fundamental Research Funds for the Central Universities”.
文摘Transition-metal-catalyzed cross-coupling reactions as very efficient and atom-economical approaches have been widely used to build up complex heterocyclic compounds.However,modification of 2-oxyl benzimidazole skeleton using maleimide compounds via C–H activation has remained unprecedented.Herein,we developed a rhodium(III)-catalyzed[5+1]cascade spiroannulation to construct diversified novel benzimidazole-incorporated spirosuccinimide derivatives from 2-oxyl benzimidazoles and maleimides.