192583-94-1Relevant academic research and scientific papers
NMR study of intermediates in the bulky diphosphite modified rhodium catalysed hydroformylation
Van Rooy, Annemiek,Kamer, Paul C. J.,Van Leeuwen, Piet W. N. M.
, p. 201 - 207 (1997)
The stoichiometric hydroformylation reaction of allyldiphenylphosphine with RhH(CO)2(2) (2 is a bulky diphosphite) was studied using 1H and 31P NMR spectroscopy. Reaction of equimolar amounts in benzene resulted in the formation of RhH(CO)(CH2=CHCH2PPh2)(2) in which all three phosphorus ligands are coordinated equatorially (4). When 4 was heated, hydride migration occurred leading to two products. Migration to the terminal carbon gave 5, Rh(CO)(PPh2CH2CH2CH2)(2). Migration of the hydride to the internal carbon atom was rapidly followed by CO insertion, resulting in the acyl compound 6, containing a five-membered rhodacycle. Complex 6 did not undergo reaction with H2. Reaction of 5 with CO reversibly yielded acyl complex 7, containing a six-membered rhodacycle. Hydrogenation of 5 yielded 8, the diphenylpropylphosphine analogue of 4.
