Synthesis of chiral germanium center enabled by poly-deborylative alkylation and desymmetrization

Abstract

Abstract Chiral germanium centers are historically undervalued due to their extremely limited synthetic accessibility. Although germanium shares similar chemical properties with silicon, synthesizing chiral germanium centers proves significantly more challenging. To facilitate rapid access to chiral germanium centers, we develop two synthetic strategies: deborylative alkylation of germanium chlorides and copper-catalyzed diol desymmetrization. The α-boryl carbanion is demonstrated to be an exceptional coupling partner for germanium chloride, yielding 1,3-prochiral diols, which subsequently undergo copper-catalyzed desymmetrization to afford chiral germanium centers. By combining these two synthetic methodologies, we successfully transform simple germanium tetrachloride into a chiral germanium center in merely four steps, representing a significant advancement in main-group element chirality. Additionally, this strategy efficiently facilitates the construction of chiral silicon-stereogenic centers as well. Subsequent deoxygenative cross-coupling reactions of the chiral germanium products further expand the scope of organogermanium chemistry, revealing entirely new synthetic possibilities.