Final Report Summary - CMETC (Selective Carbon-Carbon Bond Activation: A Wellspring of Untapped Reactivity)
The distant and selective activation of unreactive C−H and C−C bonds remains one of the biggest challenges in organic chemistry. In recent years, the development of remote functionalization has received growing interest as it allows for the activation of rather challenging C−H and C−C bonds distant from the initiation point by means of a “metal-walk. A “metal-walk” or “chain-walk” is defined by an iterative series of consecutive 1,2- or 1,3-hydride shifts of a metal complex along a single hydrocarbon chain. With this approach, simple building blocks or mixtures thereof can be transformed into complex scaffolds in a convergent and unified strategy. Synthetic organic strategies that enable the catalytic and rapid assembly of a large array of organic compounds that possess multiple stereocenters in acyclic systems are somewhat rare, especially when it comes to reaching today’s high standards of efficiency and selectivity. In particular, the catalytic preparation of a three-dimensional molecular layout of a simple acyclic hydrocarbon skeleton that possesses several stereocenters from simple and readily available reagents still represents a vastly uncharted domain. In this research work, a rapid, modular, stereodivergent and diversity-oriented unified strategy to construct acyclic molecular frameworks that bear up to four contiguous and congested stereogenic elements, with remarkably high levels of stereocontrol and in only few catalytic steps from commercially available starting materials. One key-elements of all the strategies investigated relied on selective C–C bond cleavage of a cyclopropane, easily prepared by catalytic enntioselective carbometallation of cyclopropenes.