基于硫族元素化学的烯丙位碳氢键烷基化反应

本项目的研究目标，是通过发展新的硫元素、硒元素的化学，来实现对烯丙位碳氢键的烷基化，包括不对称的烯丙位碳氢键烷基化反应。近年来，过渡金属催化的碳氢键官能化反应受到了学术界和工业界的极大关注，很多新颖的合成方法得以被开发和应用。但基于主族元素化学的碳氢键官能化反应相对而言就比较少见，还有待更深入的基础研究。我们希望能够实现一类新型的基于硫族元素化学的烯丙位碳氢键烷基化反应：通过烯烃底物与亚砜、亚硒砜等试剂分别在适当条件下发生类似烯反应的过程，以及随后在碱性或中性条件下生成的硫叶立德、硒叶立德的[2,3]重排反应，就可以得到相应的烯丙位碳氢键烷基化的产物，并以其为原料合成一系列的衍生物。我们还特别希望考查一系列手性试剂或手性催化剂的策略，探索实现高对映选择性的不对称烯丙位碳氢键烷基化的可能性。

The target of this proposal is to realize allylic C-H alkylation reactions through the development of some new sulfur or selenium chemistry, including the corresponding asymmetric versions. Recently, transition-metal catalyzed C-H functionalization reactions have attracted great attention in both academic and industrial laboratories, thus many novel synthetic methods have been developed and applied. However, C-H functionalization reactions based on the chemistry of main-group elements are still relatively rare, and we need to do more fundamental research work in this field. We hope to realized a new type of allylic C-H alkylation reactions based on chalcogen chemistry: from the respective ene-type reaction between olefin substrates and sulfoxide or selenoxide reagents under suitable conditions, and subsequent [2,3] rearrangement of resulting sulfur ylides or selenium ylides under either basic or neutral conditions, we should be able to obtain corresponding allylic C-H alkylation products, and then use these products to synthesize series of derivatives. We are especially interested in using some chiral reagent or chiral catalyst strategies to explore the possibility of achieving highly enantioselective allylic C-H alkylation.