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An Original Calix[4]arene‐Containing Oligomer/Polymer Catalyst for Homogeneous Hydroformylation
Author(s) -
Mongrain Pascal,
Harvey Pierre D.
Publication year - 2008
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.200800551
Subject(s) - hydroformylation , dimer , steric effects , oligomer , chemistry , ligand (biochemistry) , polymer chemistry , catalysis , conformational isomerism , stereochemistry , rhodium , organic chemistry , molecule , receptor , biochemistry
Abstract The title compound ( 10 ) was prepared from the calix[4]arene precursor ( 11 ) to form the ligand 5,11‐bis(methyl(diphenylphosphino))‐25,26,27,28‐tetra‐ n ‐propoxy calix[4]arene ( 12 ), which was reacted with [Rh(COD)Cl] 2 (COD = 1,5‐cyclooctadienyl) and TlPF 6 as chloride scavenger, in 31% overall chemical yield. The dimer structure in solution was demonstrated by the measurements of the 31 P NMR spin‐lattice relaxation time (T 1 ) in comparison with the ligand itself. Computer modeling shows that the dimer macrocycle exhibits many possible conformers, including some with obvious steric hindrance about the Rh atom, but no apparent ring stress. 10 was tested for the catalytic homogeneous hydroformylation of hex‐1‐ene and compared with other closely related analogue systems recently reported in the literature.