4-酰基/氨基羰基/烷氧羰基取代汉斯酯参与的有机反应研究进展

Research Progress in Organic Reactions Involving 4-Acyl/Carbamoyl/Alkoxycarbonyl Substituted Hantzsch Esters

近年来,4-酰基、氨基羰基和烷氧羰基取代汉斯酯作为一种新型的自由基供体试剂,已成为当前热门的研究方向之一.该类化合物可以通过光化学、电化学或化学氧化等体系在温和条件下产生相应的酰基、氨基羰基或烷氧羰基自由基,从而发生一系列自由基加成/偶联反应.由于其所含二氢吡啶骨架具有还原性,该类自由基前体常表现出独特的反应活性,并且对于过渡金属催化、有机小分子催化的协同体系具有良好的兼容性.此外,该类反应条件通常具有环境友好、官能团适用性高以及生物兼容性良好等特点,在药物化学和化学生物学领域具有重要的研究价值.本综述将分别介绍酰基自由基、氨基羰基自由基和烷氧羰基自由基,重点探讨自由基产生体系、反应机理以及基于汉斯酯骨架的合成策略所具有的独特性和应用.

In recent years,4-acyl/carbamoyl/alkoxycarbonyl-substituted Hantzsch esters have been increasingly utilized as a new class of radical precursor reagents,emerging as one of major research topics for synthetic chemists.These compounds can generate the corresponding acyl,carbamoyl,and alkoxycarbonyl radicals under mild conditions through photochemical,electrochemical,or chemical oxidation systems,leading to a wide array of radical addition/coupling reactions.Due to the reducibility of their dihydropyridine skeleton,these radical precursors often exhibit unique reactivities and display good compatibility with transition metal-catalysis and organocatalysis systems.In addition,the reported reaction conditions typically feature for environmental friendliness,highly functional group-tolerance,and biocompatibility,which should have significant research value in the fields of medicinal chemistry and chemical biology.Herein,this review summarizes the research progress of acyl,carbamoyl and alkoxycarbonyl radicals,and focuses on radical generation system,mechanistic underpinnings,as well as the uniqueness and applications of the synthetic strategies with such Hantzsch esters.