Two bis-triarylphosphines [5,17-dibromo-11,23-bis(diphenylphosphino)-25,26,27,28-tetrapropoxycalix [4]arene (1) and 5,17bis(diphenylphosphino)-25,26,27,28-tetrapropoxy-calix[4]arene (2)] were assessed in metal-catalysed cross-coupling reactions. Effective Heck couplings between aryl bromides and styrene were achieved when operating in DMF at 110 degrees C with 2 mol% of Pd(OAc)(2) in the presence Of Cs2CO3; the highest TOF values (ca. 50) being observed with activated aryl bromides. The coupling reaction could be extended to aryl chlorides (conversions of ca. 20% within 24 h) with both ligands, provided the reaction was carried out with NaOAc in a DMF/water mixture. The two phosphines were also found to be efficient in Suzuki cross-coupling of aryl halides with phenyl boronic acid, the turnovers being somewhat lower than those observed in Heck couplings. In Kumada-Corriu cross-coupling of aryl halides with phenylmagnesium bromide, remarkable activities were reached in the presence of palladium or nickel. TONs up to 800 mol(converted PhCl).mol(Ni)(-1) were observed for the conversion of chlorobenzene into biphenyl. Unlike the mono-triaryl phosphine PPh3, ligands 1 and 2 both promote palladium-catalysed Suzuki and Kumada-Corriu couplings involving chlorobenzene. (c) 2005 Elsevier B.V All rights reserved.