【作者】 王楠；

【导师】 潘玲；

【作者基本信息】 东北师范大学 ， 有机化学， 2025， 硕士

【摘要】 呋喃及其衍生物作为一类重要的有机化合物,广泛存在于天然产物、药物和生物活性分子中。呋喃化合物的合成方式多样,近年来酸碱催化、过渡金属催化的[3+2]环合反应逐渐成为合成呋喃化合物的重要方法,但依然存在官能团耐受性较差、过渡金属催化剂成本昂贵等问题。因此,在绿色温和的条件下从廉价易得原料出发高效合成呋喃化合物仍是非常引人关注的研究课题。二硫缩烯酮及其类似物作为独特的极化烯烃,具有廉价易得、反应位点多样等优点,适用于发展多样的多组分串联反应,被广泛应用于各种碳、杂环化合物的合成中。近年来,本课题组通过可见光催化实现了以二硫缩烯酮作为自由基受体的丰富的串联反应。在温和的反应条件下,无需过渡金属和酸碱添加剂即可构建多种重要的有机化合物。因此,本文围绕呋喃化合物的合成,在可见光催化下研究了以二硫缩烯酮为双原子组分的[3+2]环合反应。1)研究了由二硫缩烯酮与1,3-环己二酮合成多取代呋喃的[3+2]环合反应。通过反应条件的优化发现,在可见光催化下,以曙红Y为光催化剂,以过硫酸铵为自由基引发助剂,可以良好至优异的产率获得多样的呋喃化合物。通过自由基捕获、荧光淬灭等机理验证实验提出了可能的反应机理。该反应室温下即可进行,具有良好的官能团耐受性。不仅可以应用于医药中间体的修饰,还可在日光照射条件下实现克级合成,具有较好的实用性。2)通过二硫缩烯酮与4-羟基香豆素的[3+2]环合反应,以可见光激发4-羟基香豆素,无需使用额外光催化剂即可以较高产率合成呋喃并香豆素化合物。本论文将可见光催化与二硫缩烯酮的独特反应性相结合,具有反应条件绿色温和、反应物廉价易得、底物适用范围宽泛等优点,为多取代呋喃化合物的合成提供了新颖、绿色的合成策略。更多还原

【Abstract】 Furan and its derivatives represent an important class of organic compounds widely present in natural products,pharmaceuticals,and bioactive molecules.Although various synthetic approaches for furan compounds have been developed,including acid/base-catalyzed and transition-metal-catalyzed[3+2]cycloaddition reactions in recent years,current methods still face challenges such as limited functional group tolerance and high costs associated with transition metal catalysts.Consequently,developing efficient strategies for synthesizing furan derivatives from readily available starting materials under green and mild conditions remains an attractive research objective.Ketene dithioacetals and their analogues,as unique polarized alkenes,have emerged as versatile building blocks due to their availability,structural diversity,and multiple reactive sites.These characteristics make them particularly suitable to diverse multicomponent tandem reactions for the synthesis of various carbo/heterocyclic compounds.Building upon our group’s previous studies in visible-light-mediated tandem reactions using ketene dithioacetals as radical acceptors under transition-metal-free conditions,this dissertation focuses on developing[3+2]cyclization strategies employing ketene dithioacetals as dual-atom synthons for the synthesis of poly-substituted furans under photocatalysis.The main research contents include:1.Visible-light-mediated[3+2]cyclizations between ketene dithioacetals and1,3-cyclohexanediones was developed for constructing multi-substituted furans.After careful optimization,the reactions employing Eosin Y as the photocatalyst and ammonium persulfate as the radical initiator achieved good to excellent yields under ambient conditions.Mechanistic investigations involving radical trapping experiments and fluorescence quenching studies revealed a plausible reaction pathway.These reactions showed broad functional group compatibility and practical utility through successful gram-scale synthesis under natural sunlight and modification of pharmaceutical intermediates.2.Photocatalyst-free strategy for synthesizing furan-fused pyranones has been developed via visible-light excitation of 4-hydroxycoumarin and its following[3+2]cyclization with ketene dithioacetals.This approach could proceed without additional photocatalysts while maintain high reaction efficiency.This thesis integrates the unique reactivity of ketene dithioacetals with visible-light photocatalysis,offering a novel and sustainable synthetic strategy for poly-substituted furans.This strategy features environmentally benign conditions,cost-effective reactants,and broad substrates applicability,providing valuable insights for green synthetic chemistry.更多还原