清华大学刘强团队开发了一种适用于极性不饱和化合物加氢的通用高效NHC基NNC钳型锰催化剂。相关研究成果于2023年4月7日发表在《德国应用化学》。

金属氢化物配合物的反应性可以通过修饰辅助配体来控制。为了提高关键Mn–H中间体的氢化物供给能力并降低空间位阻，研究人员报道了一种用于氢化反应的通用且高效的基于NHC的NNC钳型Mn催化剂的合理设计策略。新开发的催化剂表现出比相应的NNP钳型Mn催化剂更高的活性，因为它通过π-反键相互作用降低了空间位阻并提高了Mn–Hσ-键合轨道能级。

使用这种高活性的NNC钳型Mn催化剂，在相对温和的条件下成功地氢化了一系列丰富的极性不饱和化合物（>80个实例），包括酯、N-杂芳烃、酰胺、碳酸盐和尿素衍生物。

该项工作代表了通常不含膦的Mn催化氢化系统的一个罕见例子。

附：英文原文

Title: A Tailored Versatile and Efficient NHC-Based NNC-Pincer Manganese Catalyst for Hydrogenation of Polar Unsaturated Compounds

Author: Zeyuan Wei, Hengxu Li, Yujie Wang, Qiang Liu

Issue&Volume: 2023-04-07

Abstract: The reactivity of metal-hydride complexes can be harnessed by the modification of ancillary ligands. With the aim of improving the hydride-donor ability of the key Mn–H intermediate and reducing steric hindrance, we herein report the rational design of a versatile and efficient NHC-based NNC-pincer Mn catalyst for hydrogenation reactions. This newly developed catalyst exhibited higher activity than the corresponding NNP-pincer Mn catalyst owing to its reduced steric hindrance and enhanced Mn–H σ-bonding orbital energy level through a π-antibonding interaction. Using this highly active NNC-pincer Mn catalyst, a rich array of polar unsaturated compounds (>80 examples) including esters, N-heteroarenes, amides, carbonates, and urea derivatives, were successfully hydrogenated under relatively mild conditions. This work represents a rare example of a general phosphine-free Mn-catalyzed hydrogenation system.

DOI: 10.1002/anie.202301042

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202301042