Hydrogenation with Homogeneous Palladium Nanoparticle Catalyst
Selective synthesis of cis-alkenes and amines
cis-Alkenes and amines, which are useful as raw materials for pharmaceuticals, agricultural chemicals and other chemical products, can be synthesized efficiently through hydrogenation of alkynes, organic nitro compounds and azides. The originally developed homogeneous palladium nanoparticles can be stored in solution for longer than a year and are easy to handle in air.
Content of research
We have found that homogeneous palladium nanoparticles can be obtained by treating palladium acetate with potassium tert-butoxide or sodium borohydride in the presence of alkynes (Fig.1). The nanoparticles can be stored in solution for longer than a year and are easy to handle in air. They exhibit excellent performance as hydrogenation catalysts and can efficiently synthesize cis-alkenes (2) and amines (4 and 6) from alkynes (1), organic azide compounds (3) and aromatic nitro compounds (5), respectively. They have excellent cis-alkene selectivity and functional group tolerance (no loss of the ketone, aldehyde, or benzylic hydroxy group, etc.). The catalytic activity is extremely high; the reaction proceeds quickly using only 1/1000 to 1/5000 equivalent of palladium of the substrate (raw material). It also has excellent economic efficiency and convenience, and we are examining the possibility of commercializing it in cooperation with companies.
Potential for social implementation
- ・It can be used to synthesize various materials for chemical products, including pharmaceuticals and agricultural chemicals. The hydrogenation of alkynes to cis-alkenes does not require the addition of hazardous lead. We can also supply nanoparticle catalysts.
Appealing points to industry and local governments
This reaction is a simple and clean way to synthesize cis-alkenes and amine compounds, which are useful as raw materials for chemical products, through hydrogenation. The catalyst can be handled in air and is more active than the commonly used Pd/C. We are examining the possibility of commercializing it in cooperation with companies. We can also handle its synthesis from fine to bulk, so please contact us if you are interested.