High‐Performance RuCl3 Catalyst Systems for Hydro‐Esterification of Methyl Formate and Ethylene

Summary of main observation and conclusionRuCl3 catalyst system has many advantages for the hydro‐esterification of methyl formate and ethylene to methyl propionate. However, the unsatisfied performance restricts the development of this route. In this work, high‐performance RuCl3 catalyst systems (RuCl3‐[PPN]Cl‐Et4NI and RuCl3‐NaI) are firstly reported for this reaction. In RuCl3‐[PPN]Cl‐Et4NI catalyst system, the conversion of methyl formate and the selectivity to methyl propionate are 93.9% and 90.9% at mild reaction conditions (165°C, 2.5 MPa), respectively. Noticeably, a simple inorganic RuCl3‐NaI catalyst system achieves 88.8% conversion of methyl formate and 97.6% selectivity to methyl propionate (86.7% yield) at same conditions. NaI, as a promoter, may inhibit the decomposition of methyl formate and be conducive to the formation of methyl propionate. The effects of solvents and promoters are investigated in detail. In addition, the reaction mechanism has been also analyzed. It is hoped to lay a certain foundation for further industrial application.