1,3,2,4-Diazadiphosphetidines as Ligand and Base for Palladium-Catalyzed Suzuki-Miyaura, Sonogashira-Hagihara, and Homocoupling Reactions of Aryl Halides under Heterogeneous Conditions in Water

1,3,2,4-Diazadiphosphetidines as easily prepared, cheap, and air-stable P(III) containing ligands are successfully used for the efficient C-C bond formation via Suzuki-Miyaura, Sonogashira-Hagihara, and homocoupling reactions of aryl iodides, bromides, and chlorides. The reactions occur heterogeneously in refluxing water and the nitrogen atoms in these ligands behave as base to exclude the need to add internally base. The ligand together with its Pd(0) complex is easily separated by filtration and reused for several runs.