过渡金属铬调控光催化环化反应研究进展

如何运用更加经济、环境友好的方式制备具有生物/药理活性的化合物是有机合成、生物医药领域的重要问题。近年来发展的过渡金属催化光氧化还原反应为解决上述问题提供了契机。其中,相对于传统的钌/铱络合物催化剂,新型第一周期过渡金属铬催化剂在该领域的开发及应用备受关注。烯/炔的2+N]环化反应是过渡金属光敏试剂催化的一个经典反应类型,通常表现出高化学、区域及立体选择性,而且产物是很多药物分子的基本结构单元,本文围绕铬调控光催化2+N]环化反应以及机理研究进行综述,并对其中有待进一步研究的方向进行展望,希望为铬调控光催化环化反应的深入理解以及新型光氧化还原催化剂在该类反应中的发展提供启发。

Review on Photocatalyzed Cycloaddition Reaction with Chromium Catalysts

The preparation of biologically/pharmacologically active compounds via economical and environmentally friendly strategies have received increasing attention in the past century, and show great utility in organic synthesis, pharmaceutical chemistry and bio-chemistry. The recent development of transition metal catalyzed photoredox reaction sheds light on this problem. Nonetheless, the replacement of the rare-metal catalyst (Ru or Ir complexes) with earth-abundant metal catalysts (Chromium catalysts) is unambiguously more attractive for practical applications. To this end, the chromium complex as the photocatalyst have been successfully accomplished with high activities. The high chemo-, regio- and stereo-selectivity 2+N] cycloaddition of alkene/alkyne with photocatalysts was the most general protocol to form important ring motif in various natural products and medicinally active compounds. In this study, the recent experimental and theoretical exploration on Cr complex catalyzed photoredox 2+N] cycloaddition reaction were reviewed. On this basis, the unsettled problems and future development direction were prospected. We hope the provided insights could benefit the deep understanding of Cr complexes catalysed 2+N] cycloaddition and the development of new first-row transition metal catalyst and synthetic strategies.