Engineering Research Center of Advanced Rare Earth Materials (Ministry of Education), Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University, Beijing, 100084, China.
Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China.
Angew Chem Int Ed Engl. 2023 Jun 5;62(23):e202301042. doi: 10.1002/anie.202301042. Epub 2023 May 3.
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.
通过修饰辅助配体，可以利用金属氢化物配合物的反应性。为了提高关键 Mn-H 中间体的氢给体能力并降低空间位阻，我们在此合理设计了一种通用且高效的基于 NHC 的 NNC-夹钳 Mn 催化剂，用于氢化反应。由于空间位阻降低以及通过π反键相互作用增强了 Mn-H σ 键轨道能级，这种新开发的催化剂比相应的 NNP-夹钳 Mn 催化剂具有更高的活性。使用这种高活性的 NNC-夹钳 Mn 催化剂，在相对温和的条件下成功氢化了丰富的极性不饱和化合物（>80 个实例），包括酯、N-杂芳环、酰胺、碳酸酯和脲衍生物。这项工作代表了一种罕见的通用膦自由 Mn 催化氢化体系的实例。
