Modularity in the C_sp3 Space─Alkyl Germanes as Orthogonal Molecular Handles for Chemoselective Diversification

Abstract

To meet the need for a rapid, streamlined, and potentially automatable molecule synthesis, modular coupling approaches are highly desired. While the diversification of aromatic molecules, i.e., Csp2 space, has greatly advanced, modular syntheses in the Csp3 space are comparably much less developed. This report explores the potential of alternative functional handles, i.e., alkyl germanes, in this context, which combine features of stability and synthesizability with selective reactivity. We show the chemoselective functionalization of alkyl germanes (R-GeEt3) under photoredox conditions (Giese addition) and the implementation in a modular building block, which allows for selective diversification of Csp3-halogen vs Csp3-Bpin vs Csp3-GeEt3 sites.