Abstract A new tetraphosphine, the cis-cis-cis-1, 2, 3, 4-tetrakis (diphenylphosphinomethyl) cyclopentane (Tedicyp) has been synthesized and used in palladium-catalyzed reactions. This tetraphosphine in combination with [Pd (C 3 H 5) Cl] 2 affords a very efficient catalyst for coupling reactions. Turnover numbers of 980 000 for allylic amination, 9 800 000 for allylic alkylation and 97 000 000 for Suzuki cross-coupling can be obtained in the presence of ...