We report the reactivity of triacylgermenolate (1) and geminal bisgermenolate (13) toward group 14 halides under mechanochemical conditions, enabling efficient access to novel acylgermanes. Reactions with halosilanes afforded a series of silyl-substituted acylgermanes (3-7), while treatment with chlorogermanes and chlorostannanes yielded Ge-Ge and Ge-Sn bonded acylgermanes (8-11). In contrast, the bisgermenolate displayed divergent reactivity, forming unprecedented four-membered Ge-Ge and Ge-Sn ring systems (15, 16). UV-Vis spectroscopy revealed pronounced bathochromic shifts and enhanced absorption for the heavier congeners, with photo-CIDNP experiments confirming α-cleavage and radical generation from the cyclic Ge-Ge compound. Overall, these findings establish triacyl- and bisgermenolates as versatile building blocks for accessing novel acylgermanes with tunable bonding motifs and photochemical properties.
Sen et al. (Tue,) studied this question.