Premium
Water‐Soluble, Disulfonated alpha‐Diimine Rhodium(I) Complexes: Synthesis, Characterisation and Application as Catalyst Precursors in the Hydroformylation of 1‐Octene
Author(s) -
Omosun Nikechukwu N.,
Smith Gregory S.
Publication year - 2019
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201900317
Subject(s) - chemistry , rhodium , hydroformylation , diimine , catalysis , cyclooctadiene , medicinal chemistry , aldehyde , regioselectivity , organic chemistry
The synthesis and characterisation of two new water‐soluble Rh I mononuclear 1,4‐diazabutadiene (DAD s ) complexes of general formula: [Rh(DAD s ‐R)(COD)], where (DAD s = sulfonated‐tagged–1,4‐diazabutadiene, COD = cyclooctadiene; and R = H or C 10 H 8 ), are described. The rhodium(I) complexes were obtained via a complexation reaction of [Rh(COD)(MeCN) 2 ]BF 4 with the sulfonated α‐diimine (DAD) ligands, which were previously obtained from a Schiff base condensation reaction of 4‐aminophenol with either 1,2‐ethanedione or acenapthenequinone. All rhodium complexes and their precursor ligands were characterised using 1 H NMR, 13 C NMR, FT‐IR spectroscopy and mass spectrometry. Their performance as catalyst precursors in the hydroformylation of 1‐octene was assessed and compared to those of the non‐sulfonated Rh I mononuclear 1,4‐diazabutadiene (DAD) complexes. Utilisation of the water soluble [Rh(DAD s ‐R)(COD)] lead to high conversions and regioselectivity (linear/branched aldehyde ratio) in the aqueous biphasic hydroformylation of 1‐octene. Additionally, the catalysts were recovered by phase separation and are reusable over four consecutive catalytic runs without significant loss in catalytic activity.