94. trans-Ge/B 1,1-Hydroboration of Alkynylgermanes with 9‑BBN

An, Z.-L.;# Chen, C.;# Yu, A.-X.;  Cao, D.-X.; Jiang, Y.-Y.;*  Xiao, B.* Org. Lett. 2025, 27, 4079−4084. Download Link.

A 1,1-hydroboration of alkynylgermanes with unique transGe/B stereochemistry under transition-metal-free conditions is reported. Mechanistic studies suggest that a pathway involving α boration followed by a stepwise 1,2-Ge/H shift on the intermediate structurally lies between an alkyne−Ge+ π complex and a typical vinyl cation. The resulting Ge/B bimetallic modules, along with a Ge*/Ge/B trimetallic variant, can be conveniently transformed into trisubstituted olefins through iterative divergent cross-coupling. This work demonstrates that incorporating metalloids into classical organic reactions may offer unconventional chemical selectivity and efficient synthetic applications.