Catalyst-free transfer hydrogenation of activated alkenes exploiting isopropanol as the sole and traceless reductant

• Published in: Green chemistry : an international journal and green chemistry resource : GC 2023-01, Vol.25 (2), p.746-754
• Main Authors: Das, Tamal Kanti, Rodriguez Treviño, Agustin M, Pandiri, Sanjay, Irvankoski, Sini, Siitonen, Juha H, Rodriguez, Sara M, Yousufuddin, Muhammed, Kürti, László
• Format: Article
• Language: English
• Subjects: Alcohols; Alkenes; Catalysts; Chemical reactions; Green chemistry; Hydrogen bonds; Hydrogenation; Isopropanol; Reducing agents
• ISSN: 1463-9262; 1463-9270; 1463-9262
• DOI: 10.1039/d2gc04315g

Both metal-catalyzed and organocatalytic transfer hydrogenation reactions are widely employed for the reduction of C&z.dbd;O and C&z.dbd;N bonds. However, selective transfer hydrogenation reactions of C&z.dbd;C bonds remain challenging. Therefore, the chemoselective transfer hydrogenation of olefins under mild conditions and in the absence of metal catalysts, using readily available and inexpensive reducing agents ( i.e. primary and secondary alcohols), will mark a significant advancement towards the development of green transfer hydrogenation strategies. Described herein is an unconventional catalyst-free transfer hydrogenation reaction of activated alkenes using isopropanol as an eco-friendly reductant and solvent. The reaction gives convenient synthetic access to a wide range of substituted malonic acid half oxyesters (SMAHOs) in moderate to good yields. Mechanistic investigations point towards an unprecedented hydrogen bond-assisted transfer hydrogenation process. Described herein is an unconventional catalyst-free transfer hydrogenation reaction of activated alkenes using isopropanol as an eco-friendly reductant and solvent.