苯并异吡喃氧鎓是一类活泼化学中间体，其四氟硼酸盐（ICTBs）却是在空气环境下稳定的固体。自本研究组2009年制备首例ICTB盐并加以结构验证之后，发现其是一类具有多面性质特点的串联反应介导物质，具有深入研究和开发的巨大价值。本项目拟在本组最近3年相关研究工作的基础上，进一步研究ICTBs盐与多种化学物质之间的未知串联反应，探讨其反应规律和机理；根据对机理的理解设计新的串联反应一步快速构建特殊多环骨架，并探索这些串联化学反应在重要天然产物及其类似物合成中的应用。本项目通过化学新反应、目标导向的反应设计、机理研究以及复杂结构化合物合成等多个方面对ICTBs的性质和应用进行全面研究，力争形成一些具有理论价值和实际应用价值的成果。

Isochromenyliums are a type of reactive intermediates, and our recent research found that their tetrafluoroborates (ICTBs) are air- and moisture-stable solids. ICTBs have been found to exhibit diverse and flexible reaction behaviors in performing various cascade process since our first preparation and characterizations in 2009. Further study of such ICTBs-mediated mild and efficient cascade reactions, and exploration of their mechanisms and applications will be of high value in organic chemistry. Based on our previous findings, we plan to further explore unknown reactions of ICTBs with potential substrates, discuss their mechanisms, and attempt their application to the synthesis of bioactive natural prodcuts and their druggable analogues. The project is expected to find several novel cascade ICTBs-based transformations, and establish useful methodologies for one-step efficient synthesis of podophyllotoxin analogues for medicinal research.