Transition Metal‐Free C(sp 2 )─Ge Bond Construction and Downstream Functionalization

Organogermanes have emerged as versatile, orthogonal handles for transition metal‐free electrophilic ipso ‐substitutions. This review highlights protocols enabling the synthesis of aryl‐ and vinylgermanes and their downstream functionalization through halodegermylation and acyldegermylation to form new C─X and C─C bonds, as well as C─B bonds via borodegermylation. These reactions deliver aryl halides, ketones, and organoboranes with high chemo‐ and regioselectivity, orthogonal to boronic esters and silanes. Applications span traceless solid‐phase synthesis of π‐oligomers and the preparation of BN‐fused polycyclic aromatics for optoelectronic materials. These transition metal‐free transformations emphasize the synthetic potential of organogermanium compounds in complex molecule assembly and advanced functional materials.