Rhenium-Catalyzed C-H and C-C Bond Activation

摘要

The principles of atom economy and environmentally benign chemical reactions have generated substantial interest in the development of methods based on the functionalization of carbon-hydrogen bonds. To date, however, there have been far fewer reports on the functionalization of carbon-carbon single bonds. This is no surprise given the paramount steric obstacles a catalyst must overcome along the path to carbon-carbon bond activation. In early work in this area, Tipper and Bergman studied stoichiometric C-C bond activation, and subsequently, a variety of strategies addressing catalytic C-C bond activation have been devised. To date, however, no truly general methods exist, and this area remains a major challenge for organic synthesis. Of the systems developed thus far most have benefitted from ring strain, chelation assistance, or the formation of metal alcoholates to β-alkyl elimination to allow for the selective cleavage of the C-C single bond.