Additive-free reductive hydrodeoxygenation of fatty acids catalyzed by inexpensive simple nickel() compounds

• Published in: New journal of chemistry 2023-05, Vol.47 (17), p.8318-8325
• Main Authors: Lama, Óscar M. F, Roa, Diego A, Arévalo, Alma, García, Juventino J
• Format: Article
• Language: English
• Subjects: Additives; Alcohols; Aldehydes; Fatty acids; Hydrosilylation; Nickel; Oleic acid; Palmitic acid; Reaction intermediates; Reaction mechanisms; Reducing agents; Stearic acid
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d3nj01001e

The hydrodeoxygenation (HDO) of different fatty acids (FAs) was achieved using simple and commercially available nickel( ii ) compounds, with silanes as reducing agents under relatively mild reaction conditions. Thus, the optimized conditions include Ni(AcO) 2 ·4H 2 O (5 mol%) as a catalytic precursor and 3 eq. of PhSiH 3 at 90 °C, 16 h, and the corresponding FAs, such as palmitic acid (PA), stearic acid (SA) and oleic acid (OA), having high conversion (83% to ≥99%) and good selectivity, being specific for the reduction of the carboxylic group to yield the corresponding aldehydes, alcohols, and hydrocarbons through hydrosilylation with PhSiH 3 by fine-tuning of the reaction conditions and the use of relatively mild conditions, without requiring additives. To gain insight into the reaction mechanism, the reaction intermediate [Ni(C 15 H 31 COO) 2 (H 2 O) 2 ] was synthesized, characterized, and tested as an active catalyst. Using Ni(AcO) 2 ·4H 2 O as a catalytic precursor and PhSiH 3 , a simple and efficient catalytic system was synthesized for reducing FAs with high conversion under relatively mild conditions.