A New Tetraphosphine and Its Application in Pd-Catalyzed Suzuki Cross-Coupling Reaction

A new tetraphosphine, N,N,N',N'-tetra(diphenylphosphinomethyl)-cyclohexane-1,2-diamine (1) has been designed and synthesized from the commercially available cyclohexane-1,2-diamine as starting material. This tetraphosphine in combination with [Pd(eta(3)-C3H5)Cl](2) is a very efficient catalyst for Suzuki cross-coupling reaction. Various aryl- and heteroaryl-chlorides as well as aryl-, heteroaryl-, and alkyl-bromides could be successfully transformed to the desired products in up to 99% yield with 0.1 mol% catalyst loading.