A. Leyva, H. García, A. Corma
Jul 23, 2007
Citations
0
Influential Citations
49
Citations
Journal
Tetrahedron
Abstract
Abstract The so-called SPhos phosphine, an extremely active ligand in the amination and Suzuki coupling of sterically-hindered aryl chlorides, has been anchored on different supports such as non-soluble (cross-linked polystyrene) and soluble (non-cross-linked polystyrene and polyethyleneglycol) polymers, as well as high surface silica. SPhos anchored on polyethyleneglycol (PEG–SPhos) showed the best activity for both amination and Suzuki couplings. The PEG–SPhos ligand can be quantitatively recovered from the reaction mixture through precipitation with diethyl ether and recycled in four consecutive runs without loosing activity. 31P NMR spectra of the reused anchored ligand showed that deactivation of the PEG–SPhos ligand comes from the progressive oxidation of the phosphine-to-phosphine oxide.