Bench-Stable Solid Organozinc Reagents: Synthesis and Application

Organozinc reagents transformed organic synthesis due to their compatibility with functional groups. Nonetheless, organozinc reagents are susceptible to air and moisture and are often produced in solution form, which restricts their industrial application. Solid organozinc pivalates (RZnX·Mg(OPiv)2·nLiCl) were developed by the reaction of RMgX with Zn(OPiv)2·2LiCl. (CF3)2Zn·TMEDA was synthesized from air-stable (DMPU)2Zn(perfluoroalkyl)2, which was derived from ZnEt2 and perfluoroalkyl iodide. A method that generates stable monomeric organozinc species in a single step, eliminates solvents such as DMA, uses commercial Zn, and eliminates stoichiometric additives like LiCl is very desirable. We demonstrate the direct synthesis of stable solid organozinc reagents (15 examples), including sterically demanding tBuZnBr, from commercial zinc. They exhibit high stability at room temperature and offer excellent yields in open-air palladium catalysis. These reagents are monomeric, devoid of complex mixtures. Single-crystal XRD, and especially the NMR spectrum, were obtained for these reagents.