31502-36-0Relevant academic research and scientific papers
A mechanistic study of rhodium tri(o-t-butylphenyl)phosphite complexes as hydroformylation catalysts
Jongsma, T.,Challa, G.,Leeuwen, P. W. N. M. van
, p. 121 - 128 (1991)
A mechanistic study of the hydroformylation cycle with a rhodium tri(o-t-butylphenyl)phosphite complex as catalyst is presented.Spectroscopic experiments prove that under hydroformylation conditions this complex is coordinated by only one phosphite.The co
Contiguous Quaternary Centers from a AuI-Catalyzed Nazarov Cyclization
Congmon, Jonathan,Tius, Marcus A.
supporting information, p. 2926 - 2930 (2018/06/27)
The cationic AuI-catalyzed cyclization of highly substituted enynes has been shown to provide cyclopentenones with up to two contiguous, all-carbon atom quaternary centers in a diastereospecific process. In the more challenging examples in whic
On the mechanism of the nickel-catalysed regioselective cyclodimerization of isoprene
van Leeuwen,Roobeek
, p. 1973 - 1983 (2007/10/02)
A study of various Ni-ligand catalysed oligomerizations of isoprene has shown that with π-acidic P ligands the selectivity to cyclodimers amount to 97%. A new type of ligand is introduced, viz. fluoroalkyl phosphites having π-acceptor properties comparable to those of, e.g. PCl3. With tris(hexafluoroisopropyl) phosphite the main product is 1,4-dimethy1-4-vinylcyclohexene. A detailed explanation based on a two-step mechanism is given. As to the first step, for a series of ligands having similar steric properties the changes in product distribution as a function of the electronic ligand parameter are explained in terms of a gradual change in HOMO-LUMO interactions between Ni and the olefins, with strong π-acidic ligands promoting the head-to-head coupling of the isoprene molecules. The second step, involving reductive elimination of a cyclodimer from the metal, shows an increasing selectivity towards substituted cyclohexenes for the head-to-head and tail-to-tail intermediates with increasing π-acidity of the ligand. The qualitative orbital treatment presented as an explanation is also applicable to reactions found for other metallacyclopentanes.
