氨基酸作为瞬态导向基在碳氢键活化反应中的研究进展

Research Progress of Amino Acids as Transient Directing Groups in C-H Bond Activation Reactions

近年来,基于瞬态导向策略的碳氢键活化获得了极大关注,与传统的碳氢键活化反应相比,瞬态导向基团辅助碳氢键活化无需额外进行导向基的预安装和后期去除步骤,大大提高了反应的原子和步骤经济性.在目前发现的瞬态导向基中,氨基酸作为导向基进行碳氢活化获得了重大成果.氨基酸具有廉价易得、来源广泛及结构丰富多样的优点,通过使用α或β-氨基酸进行导向控制碳氢活化反应的位点选择性,并且可利用氨基酸的固有手性诱导反应的立体选择性.综述了近年来以氨基酸为瞬态导向基、过渡金属催化的碳氢键活化研究进展,按照不同氨基酸导向基所进行的各类底物的C—H官能团化反应进行分类,并对该领域目前的局限和未来发展进行了总结和展望.

In recent years,the transient directing group(TDG)-based strategy of C—H activation has attracted significant attention.Compared with the typical C—H activation reactions,TDG-assisted C—H activation does not require external pre-installation and post-removal steps of directing groups,which significantly improve the atom and step economy.Amino acid-based TDGs for C—H activation have achieved significant successes among the known TDGs.Amino acids have the advantages including low cost,widely existing and diverse structures.The site selectivity of C—H activation can be controlled by usingα-orβ-amino acids.By using the inherent chirality of amino acids,the stereo-selectivity of reactions can be realized.The research progress of transition-metal-catalyzed C—H bond activation and functionalization with amino acids as TDGs in recent years is summarized,which is classified according to the type of amino acids for C—H activation reactions of various substrates.Finally,the limitations of previous works and perspectives on this cutting-edge area are also described.