Light-enhancing ketone transfer hydrogenation catalyzed by diphosphine phenanthroline ruthenium complexes

Author(s)

Cicero Masson, Gustavo Henrique ; Ballico, Maurizio ; Goi, Beatriz Eleuterio ; de Carvalho, Valdemiro Pereira ; Baratta, Walter

• Document type: Journal article
• Source: MOLECULAR CATALYSIS; v. 564, p. 11-pg., 2024-06-27.

Abstract

The cationic phenanthroline ruthenium derivatives [Ru(OAc)(dppb)(NN)]OAc (NN = phen 1 , imidazo[4,5-f] [1,10]phenanthroline 2 ) have been obtained in high yield by reaction of the acetate [Ru(OAc) 2 dppb] with the corresponding NN ligand. The dinuclear cyclometalated [(dppb)( eta 2 -OAc)(Ru( mu -NN-phenimid-NC)Ru( eta 2 -OAc) (dppb)]OAc ( 3 ) has been prepared from 2 with [Ru(OAc) 2 (dppb)] via elimination of acetic acid. The characterization of these compounds has been carried out by NMR, FT-IR, UV - Vis, conductivity and cyclic voltammetry measurements. These derivatives display catalytic activity in the transfer hydrogenation of aromatic and aliphatic cyclic ketones at S/C up to 2000 in presence of NaO i Pr in 2-propanol. An increase of the rate (up to 8 times) has been observed upon irradiation at 30 and 60 degrees C (300 W Xenon Arc Lamp light source). Control experiments show that [Ru(O i Pr) 2 (dppb)(phen)] ( 1A ), formed from 1 by substitution of the acetate with the isopropoxide ligand, shows a stronger emission compared to 1 and that 1A is quenched by NaO i Pr, affording the dihydride [Ru(H) 2 (dppb)(phen)] ( 1C ) via a photo induced beta -H elimination. (AU)

• FAPESP's process: 21/13128-1 - Development of new polymeric materials via coupling of mechanistically incompatible reactions using Ru/Pd and Ru/Ni heterobimetallic catalysts
• Grantee: Valdemiro Pereira de Carvalho Júnior
• Support Opportunities: Regular Research Grants
• FAPESP's process: 21/11873-1 - Organometallic complexes of Mn(II), Fe(II) and Ni(II) as CRP2 redox photocatalysts: new strategy for light curing with LEDs
• Grantee: Beatriz Eleutério Goi Carvalho
• Support Opportunities: Regular Research Grants