过渡金属促进的二氟烷基化和一氟烷基化反应研究进展

Advances in Transition-Metal-Mediated Di-and Monofluoroalkylations

过渡金属参与的氟烷基化反应是当前有机氟化学研究的一个热点.在过去的五年里,由于新试剂新方法的发展,过渡金属促进的全氟烷基化反应取得了长足的发展.与全氟烷基化相比,二氟和一氟烷基化反应不但可以方便地向分子中引入一个或几个氟原子,还可以同时引入其它官能团,因此在合成的步骤经济性上具有比直接氟化更大的优势.尽管过渡金属促进的二氟和一氟烷基化反应是伴随着全氟烷基化反应而发展起来的,在反应形式上与后者有很多相似之处,但是二氟和一氟烷基化反应发展相对缓慢,仍然存在发展空间.在这篇综述里面,我们首次全面地总结了过渡金属促进的二氟和一氟烷基化反应在过去近三十年时间里的发展进程.全文包括五部分:第一部分是引言,从总体上介绍了二氟和一氟烷基化在氟化学中的地位;第二、三两部分着重把官能团化的二氟烷基化反应和一氟烷基化反应按照反应的种类(即:不饱和卤代烃的氟烷基化、不饱和体系碳-氢键氟烷基化、有机硼以及金属试剂的氟烷基化、不饱和碳-碳键的加成)进行了梳理;第四部分为了强调二氟和一氟甲基化在氟烷基化中的重要地位,将其单独介绍;最后一部分是总结和展望.

Transition-metal-mediated fluoroalkylation is a hot research topic in current organofluorine chemistry. In the past five years, due to the development of new perfluoroalkylation reagents and methodologies, significant progress has been made in the field of transition-metal-mediated perfluoroalkylation. Compared with perfluoroalkylation, di-and monofluoroalkylation can not only introduce fluorine atom(s) into a molecule, but also install a non-fluorinated moiety simultaneously; therefore, in organic synthesis, these reactions are of higher step economy than the direct fluorination reactions. Although analogous to transition-metal-mediated perfluoroalkylations, the di-and monofluoroalkylation have been relatively less developed; therefore, there are still many opportunities for their development. In this review, we have made a survey on transition-metal-mediated di-and monofluoroalkylation reactions that were published in the past nearly 30 years. To our knowledge, this is the first rather comprehensive review on this topic. This review is divided into five sections. The first section is the general introduction on di-and monofluoroalkylation. The second and third sections focus on the historical development of transition-metal-mediated di-and monofluoroalkylation with reagents that contain functional groups. These two sections are subdivided according to the reactions types, that is, fluoroalkylation of unsaturated organohalides, fluoroalkylation of the carbon-hydrogen bonds of unsaturated systems(arenes, alkenes, alkynes, and carbonyl compounds), fluoroalkylation of organoborane reagents and organometallic reagents, fluoroalkyl addition to unsaturated carbon-carbon bonds. The fourth section puts an emphasis on the transition-metal-promoted di-and monofluoromethylation reactions. The final section gives some perspectives on the future development of this chemistry.