953389-96-3Relevant academic research and scientific papers
Bis-(2,5-diphenylphospholanes) with sp2 carbon linkers: Synthesis and application in asymmetric hydrogenation
Fox, Martin E.,Jackson, Mark,Lennon, Ian C.,Klosin, Jerzy,Abboud, Khalil A.
, p. 775 - 784 (2008/09/18)
(Chemical Equation Presented) Four chiral diphosphine ligands consisting of bis(2,5-diphenylphospholan-1-yl) groups connected by the sp2 carbon linkers 2,3-quinoxaline ((S,S)-Ph-Quinox), 2,3-pyrazine ((S,S)-Ph-Pyrazine), maleic anhydride ((S,S)-Ph-MalPhos), and 1,1′-ferrocene ((S,S)-Ph-5-Fc) were synthesized, and their cationic [rhodium-(I)(COD)] complexes were prepared. These complexes were tested in asymmetric hydrogenation of functionalized olefins. [((S,S)-Ph-Quinox)Rh(COD)]BF4 showed high activity and selectivity against itaconate and dehydroamino acid substrates. The corresponding (S,S)-Ph-Pyrazine and (S,S)-Ph-MalPhOS complexes exhibited lower activities and selectivities. [((S,S)-Ph-S-Fc)Rh(COD)]BF4 showed high activity with low selectivity for these substrates, but high activity and selectivity against 2-C-substituted cinnamate salts, whereas rhodium complexes of (S,S)-Ph-Quinox and (R,R)-Ph-BPE showed low activity and selectivity against 2-C-substituted cinnamate salts.
BISPHOSPHOLANES FOR USE AS CATALYSTS IN ASYMMETRIC REACTIONS
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Page/Page column 35, (2008/06/13)
The invention is a set of novel bisphospholane ligands that can be complexed with transition metals. These complexes are useful as catalysts in asymmetric reactions such as asymmetric hydrogenation.
