New Catalytic Strategies for Metal-Free C-C Bond Formation

Transition metal-catalysed cross-coupling is a uniquely powerful tool for the formation of sp2-sp2 and sp2-sp3 C-C linkages. However, challenges inherent in sp3-sp3 couplings have largely impeded the development of generally applicable solutions to this problem. Moreover, a reliance on transition metal catalysts to forge alkyl-alkyl linkages can lead to problems in a drug development setting, as these catalysts are prone to poisoning by the basic functionalities commonly encountered in drug-like molecules. Additionally, trace metal contamination is a serious concern in a pharmaceutical manufacture. For these reasons, a metal-free approach to C(sp3)-C(sp3) bond formation could prove transformative in organic synthesis.

In this project, we will explore a number of approaches to metal-free C(sp3)-C(sp3) bond formation without reliance on metal catalysis, using visible-light photocatalysis to generate radical intermediates. Our initial objective is to develop a novel, one-pot homologation process for alkyl carboxylic acids, extending an aliphatic chain by a single carbon. Such a process would be synthetically powerful, but is currently unachievable in a direct fashion.