78856-62-9Relevant academic research and scientific papers
Co-ordination Chemistry of Sulphines. Part 4. Influence of the Phosphine Cone Angle on both the Oxidative Addition of Carbon-Sulphur and Carbon-Chlorine Side Bonds in 0(PR3)2(XYC=S=O)> Complexes and the (E)-(Z) Isomerization
Gosselink, Johan W.,Bulthuis, Huibert,Van Koten, Gerard
, p. 1342 - 1348 (2007/10/02)
The co-ordination compounds 02(C12H8CSO)> (5a) (C12H8CSO=fluorene-9-ylidenesulphine), 02> (E)-(5b), 02> (Z)-5b, 02> (5c) (R=p-MeC6H4), and 02> (E)-(5d') may be synthesized with retention of configuration from 0(cod)2>, P(C6H11)3, and the corresponding sulphines (cod=cyclo-octa-1,5-diene).The complexes (5a) and (5c) remain unchanged in CDCl3 solution, while (Z)-(5b) isomerizes to (E)-(5b) and vica versa, until a 4:1 (E):(Z) equilibrium is reached.The complex (E)-(5d') undergoes in CDCl3 a fast oxidative addition of the C-Cl side bond, yielding the kinetically preferred cis-(E)-IICl(PhSCSO)2> (E)-(6d'), which then isomerizes to the thermodynamically more stable trans-(E)- and -(Z)-IICl(PhSCSO)2> (E)- and (Z)-(7d').This shows that replacement of the PPh3 ligands by bulkier P(C6H11)3 ligands increases the barrier to intramoleculaar C-S oxidative addition.An overall mechanism for the intramolecular C-S oxidative-addition and reductive-coupling reactions on Pt(PR3)2 centres (R=C6H11 or Ph) and the (E)-(Z) isomerization of co-ordinated sulphines and metal-substituted sulphines (oxidative-addition products) is put forward.
