Platinum Complexes of Rigid Bidentate Phosphine Ligands in the Hydroformylation of 1-Octene

• Published in: Organometallics Vol. 24; no. 22; pp. 5377 - 5382
• Main Authors: van der Vlugt, Jarl Ivar, van Duren, Ruben, Batema, Guido D, den Heeten, René, Meetsma, Auke, Fraanje, Jan, Goubitz, Kees, Kamer, Paul C. J, van Leeuwen, Piet W. N. M, Vogt, Dieter
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 24.10.2005; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Inorganic & Nuclear; Chemistry, Organic; Physical Sciences; Science & Technology; PHOSPHORUS; DIPHOSPHINE LIGANDS; ASYMMETRIC HYDROFORMYLATION; CATALYTIC-SYSTEM; NUCLEAR-MAGNETIC-RESONANCE; REACTIVITY; OLEFINS; LINEAR BUTENES; STYRENE; SCATTERING FACTORS
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/om050575a

The synthesis of the two novel diphosphine compounds 1,2-bis(3-(diphenylphosphino)-4-methoxyphenyl)benzene (1; Terphos), and 1,2-bis(2-diphenylphosphino)benzene (2), both derived from a terphenyl backbone structure, are described. Straightforward synthetic routes have been employed to obtain these ligands in good yields from cheap starting materials. The coordination of ligands 1 and 2 with PtCl2(cod) has been studied by NMR spectroscopy, and the X-ray crystal structures of the resulting complexes 4 and 5 were determined. The 31P NMR spectra of the mononuclear products demonstrate solely cis coordination for both bidentate ligands, with corresponding coupling constants J Pt - P of 3810 Hz (cis-[PtCl2(1)], complex 4) and 3712 Hz (cis-[PtCl2(2)], 5). The bite angles P1−Pt−P2 were 98.74 and 105.89°, respectively, in the distorted square-planar complexes. The new diphosphines have been applied in the platinum/tin-catalyzed hydroformylation of 1-octene, and both ligands give active and selective platinum catalysts.