Rh(I) complexes with new C2‐symmetric chiral diphosphoramidite ligands: Catalytic activity for asymmetric hydrogenation of olefins

• Published in: Applied organometallic chemistry Vol. 31; no. 12
• Main Authors: Drommi, Dario, Arena, Carmela Grazia
• Format: Journal Article
• Language: English
• Published: Chichester Wiley Subscription Services, Inc 01.12.2017
• Subjects: Alkenes; asymmetric hydrogenation; C2‐symmetric ligand; Catalysis; Catalytic activity; Chelates; Chemical synthesis; Chemistry; chiral rhodium complexes; Coordination compounds; Dimethylitaconate; diphosphoramidite; Hydrogen storage; Hydrogenation; Ligands; Rhodium
• ISSN: 0268-2605; 1099-0739
• DOI: 10.1002/aoc.3837

The design and synthesis of three new C2‐symmetric chiral diphosphoramidite ligands starting from simple and cheap building blocks have been developed. Rhodium(I) cationic complexes bearing these chelate ligands have been prepared and applied in asymmetric hydrogenation of model olefins. A rhodium complex with a diphosphoramidite containing a chiral diamine configurationally stable and two fluxional chiral biphenyl units gave higher enantioselectivity with increasing hydrogen pressure (87% ee) in the hydrogenation of dimethyl itaconate. The design and synthesis if three new C2‐symmetric chiral diphosphoramidite ligands starting from simple and cheap building blocks have been developed. Rhodium(I) cationic complexes bearing these chelate ligands have been prepared and applied in asymmetric hydrogenation of model olefins. A rhodium complex with a diphosphoramidite containing a chiral diamine configurationally stable and two fluxional chiral biphenyl units gave higher entantioselectivity with increasing hydrogen pressure (87% ee) in the hydrogenation of dimethyl itaconate.