Iron-Based Catalysts for the Hydrogenation of Esters to Alcohols

Abstract

Hydrogenation of esters is vital to the chemical industry for the production of alcohols, especially fatty alcohols that find broad applications in consumer products. Current technologies for ester hydrogenation rely on either heterogeneous catalysts operating under extreme temperatures and pressures or homogeneous catalysts containing precious metals such as ruthenium and osmium. Here, we report the hydrogenation of esters under relatively mild conditions by employing an iron-based catalyst bearing a PNP-pincer ligand. This catalytic system is also effective for the conversion of coconut oil derived fatty acid methyl esters to detergent alcohols without adding any solvent.

Iron-catalyzed reduction of carboxylic and carbonic acid derivatives

“…Related to this complex are Fe10 and Fe11, reported almost simultaneously by the groups of Beller [41], Schneider [42], and Guan and Fairweather [43], bearing an ethyl- borohydride to the dihalogeno-iron complexes Fe16 and were isolated in 68% and 55% yields from the dibromo-and dichloro-precursor, respectively (Scheme 31).…”

“…The groups of Beller and Guan and Fairweather reported simultaneously the use of another PNP pincer iron complex (Scheme 39) [41,43]. Such PNP ligand was initially described by Gusev in osmium-catalyzed hydrogenation of esters [48].…”

Reversible catalytic dehydrogenation of alcohols for energy storage

“…However, Guan and coworkers (25) have accomplished ester hydrogenation using catalyst 1. In addition to these studies, it was recently shown that the same iron complexes can also efficiently catalyze the reversible dehydrogenation-hydrogenation of N-heterocycles (26).…”

A General, Practical Triethylborane‐Catalyzed Reduction of Carbonyl Functions to Alcohols

“…[4] Knowne xamples requireharsh reaction conditions (high pressures and temperatures) and functionalitiess uch as olefin, alkyne, cyanidea nd nitro groups often compete favorably over esters for hydrogenation. [5] Catalytic hydrosilylationi sa na ttractivea lternative to hydrogenationf or am ilda nd selective ester reduction. [6] Various transition-metal catalysts ystemsw ith Ti, [7] Rh, [8] Ru, [9] Mo, [10] Zn, [11] Mn, [12] and Fe [13] metals have been reportedf or ester hydrosilylations.…”