Highly Efficient Ruthenium-Catalyzed N-Formylation of Amines with H2 and CO2

• Published in: Angewandte Chemie International Edition 2015-05, Vol.54 (21), p.6186-6189
• Main Authors: Zhang, Lei, Han, Zhaobin, Zhao, Xiaoyu, Wang, Zheng, Ding, Kuiling
• Format: Article
• Language: English
• Subjects: amines; hydrogenation; ligand effects; ruthenium; synthetic methods
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201500939

A highly efficient catalyst system based on ruthenium‐pincer‐type complexes has been discovered for N‐formylation of various amines with CO2 and H2, thus affording the corresponding formamides with excellent productivity (turnover numbers of up to 1 940 000 in a single batch) and selectivity. Using a simple catalyst recycling protocol, the catalyst was reused for 12 runs in N,N‐dimethylformamide production without significant loss of activity, thus demonstrating the potential for practical utilization of this cost‐effective process. A one‐pot two‐step procedure for hydrogenation of CO2 to methanol via the intermediacy of formamide formation has also been developed. Just a pinch: CO2 is efficiently hydrogenated for N‐formylation of various amines using ruthenium‐pincer catalysts, thus affording the corresponding formamides with extremely high turnover numbers (TONs). The catalyst was readily reused for 12 runs without significant loss of activity in N,N‐dimethylformamide production, thus demonstrating potential for practical utilization of this cost‐effective process.