Cross-coupling Reactions Using Organosodium

Takai et al. have reported a simple preparation of organosodium compounds 1 using sodium dispersion and their subsequent application for cross-coupling reactions. 1 transmetallates with zinc and boron to provide organozinc intermediate compounds via a reaction with ZnCl₂-TMEDA and organoboron compounds via a reaction with methoxyboronic acid pinacol ester, respectively. These intermediates can be applied to Negishi and Suzuki-Miyaura cross-coupling reactions in one-pot manner. In addition, direct cross-coupling of arylsodiums and arylhalides can be achieved. The preparation of organosodium compounds using sodium dispersion has several advantages such as easier utilization of inexpensive organic chlorides as starting materials and mild reaction conditions (0-30 ºC) compared to the synthesis of conventional organolithiums or organomagnesiums which require harsher or more specific and sensitive substrates.