Organogermanium(iv) compounds in photo-induced radical reactions

Located between silicon and tin in the periodic table, organogermanium compounds have comparable abundant radical properties as well. According to earlier studies, various types of germanium compounds, such as acylgermanes, hydrogermanes, tetraalkylgermanes, and digermanes, could be key reagents in radical processes. As visible-light photocatalysis has developed into a major radical-generation approach in the past decade, some of these germyl compounds have also been applied to achieve germylation or alkylation reactions, indicating the great potential of germanium in modern radical systems. In this review, the mechanism and applications of these four types of organogermanium structures in photoinduced radical reactions are summarized.