No abstract

No abstract

Several Cu(I) complexes of 2,2'-bipyridines were studied for the catalytic coupling of aryl iodides and phenols and 4,4'dimethoxy-2,2'-bipyridine was shown to be an effective ligand of CuI in 1:2 (CuI:ligand) ratio for the synthesis of a wide range of diaryl ethers (up to 97% yield) using K 3 PO 4 as base in DMF at 100°C. The catalysis was highly dependent on the reaction temperature and was successfully applied in the coupling with more attractive and challenging substrates, aryl bromides, at 140°C in good-to-excellent yields (78À 95%). Moreover, the heteroaromatic effect for the reaction was studied and gave a comparable result with phenyl group (up to 95% yield). Significantly, a structurally related N,N-bidentate ligand, 4,7dimethoxy-1,10-phenanthroline, exhibited better performance for less-reactive combinations of aryl halides and phenols.

No abstract