Synthesis of chiral multidentate tertiary arsines with As4 or As6 donor atoms

Author(s):  
Roy J. Doyle ◽  
Nicole Habermehl ◽  
Geoffrey Salem ◽  
Anthony C. Willis
Keyword(s):  
1975 ◽  
Vol 11 (1) ◽  
pp. 5-10 ◽  
Author(s):  
E.G. Leelamani ◽  
G.K.N. Reddy
Keyword(s):  

2009 ◽  
Vol 48 (15) ◽  
pp. 7482-7490 ◽  
Author(s):  
Michelle L. Weir ◽  
Ian A. Cade ◽  
Nathan L. Kilah ◽  
Xiangting Zhou ◽  
S. Bruce Wild

1984 ◽  
Vol 39 (4) ◽  
pp. 504-511 ◽  
Author(s):  
Leopold Horner ◽  
Guido Simons

By systematic variation of the structure of tertiary phosphines with ortho-phenyl substituted groups as co-catalysts of the homogeneous hydrogenation with Rhodium complexes and hexene-1 as a model compound a collection of data is obtained. By investigating the influence of the variation of the Rhodium/Phosphine-Ratio (Rh/P) (1:1,1 and 1:2,2) on the rate of the hydrogentransfer indirect conclusion can be drawn on the composition of the complexes in the equilibria responsible for the hydrogen transfer.Results: 1. Steric effects of substituents linked to the ortho-position of a phenyl group in the co-catalyst are very important (compare the Tables I-V especially Table VI).2. The rate of hydrogenation is strongly influenced by tertiary phosphines with substituents in a ortho-phenyl group capable for coordination like NR2 and SR. With Rh/P = 1:1,1 the rate of the hydrogenation of hexene-1 is mostly faster as with Rh/P = 1:2,2. Depending on steric effects the rate data can be invers.3. Tertiary arsines with o-dialkylaminophenyl groups are more effective co-catalyst as the corresponding phosphines (Table V).4. Tertiary phosphines with an ortho-alkylmercaptophenyl group (38-41) are weakly active cocatalysts using Rh/P = 1:1,1.The thioether 42 (in compounds 12 the diphenylphosphino group is exchanged by the methylmercapto group) is also a moderate active co-catalyst.5. As a conclusion: it is assumed that complexes of the structure A can coordinate with the substrates hydrogen and olefine . Complexes of the structure B seen to be to stable for the activation of the substrates.


Sign in / Sign up

Export Citation Format

Share Document