Chemistry of Nickel and Copper
In this lecture, our efforts to use the C4F8 fragment as a lynchpin for stabilizing high valent nickel so that new organic methodology can be enabled, including difficult N-N bond forming reactions will be presented. To enable such studies, new types of perfluoroalkyl dizinc reagents have been developed which could transfer the C4F8 fragment to nickel. The dizinc reagents were found to have interesting properties in their own rights, and could be used to prepare novel organics bearing fluoroalkyl-containing ring systems and perfluoroalkyl tethers. The zinc chemistry overcomes problems with traditional reagents for difluoromethylene transfer such as short half-lives of the perfluoroalkyl nucleophiles at low temperatures, low reactivities, and limited substrate scopes. These new fluoroalkylated zinc reagents can also foreseeably be used to prepare fluorinated co-polymers, and their utility in preparing small and large molecules will be discussed. Finally, the zinc chemistry has been further developed to allow for the construction of stable yet reactive reagents for the installation of the difluoromethyl (CF2H) moiety, which is an increasingly important functionality in the life sciences and materials research.