Air-Stable Phosphine Oxide Ligand

4,4,5,5-Tetramethyl-1,3,2-dioxaphospholane 2-oxide is an air-stable phosphine oxide ligand, which forms hydrogen-bond-stabilized bidentate complexes with transition metals to enhance cross-coupling reactions. In the Kumada cross-coupling reaction, for example, this ligand can be applied even to reactions with substrates having less reactivity, such as tosylates, especially electron-poor aryl or heteroaromatic tosylates, to give the corresponding coupling products in good yields.