Palladium(0) complexes of (P,P) and (P,N) ligands immobilized on silica gel as catalysts in selective Heck type carbon-carbon coupling reactions

摘要

Pd(0) complexes of Ph2P-N-PPh2 and (P,N) ligands anchored on silica gel via a -O-Si-CHCH2CH2- linker are shown to catalyze C-C coupling reactions between aryl bromides/aryl iodides, p-Y-C6H4X (where Y = NO2, Cl; X = Br, I) and acrylic acid/styrene CH2=CHR (R = Ph, COOH) in good yield, up to 92%. Only the trans product is formed selectively. The catalysts can be re-used up to 15-16 times, without significant loss of yield. Their further re-use up to 30 times is also possible, but with the yield reduced by 10-15%. (c) 2006 Elsevier Ltd. All rights reserved.