Catalytic Construction of C(sp3)-Ge Bonds: Recent Advances and Future Perspectives

Germanium (Ge), a congener of carbon, possesses unique properties that hold extensive potential for applications across multiple domains. Recent years have seen significant progress in the development of carbon-germanium bond formation strategies, particularly those for more challenging C(sp3)-Ge bonds. This review systematically summarizes the recent advances in C(sp3)-Ge bond forming methodologies, with particular emphasis on (1) the versatility of transition-metals, including iron, nickel, copper, rhodium and palladium, as catalysts in broadening reaction scope and controlling selectivity; (2) the powerfulness of organic photocatalysis in achieving mild and selective bond formation, and (3) the sustainability of catalytic electrosynthesis in facilitating chemical oxidant-/reductant-free conversions. Additionally, examples of (4) non-catalytic strategies are also discussed. The representative scopes, as well as mechanistic proposals, of these protocols are highlighted. Through an overview on the current state of research, this review aims to offer insights into the catalytic construction of C(sp3)-Ge bonds, and provide perspectives on future research directions to address the current challenges.