Copper‐Catalyzed Electrophilic Amination of Alkoxyarylsilanes

Catalytic alkoxysilylation of C-H bonds with tert-butyl-substituted alkoxysilyldiazenes

Organoalkoxysilanes (e.g. R-SiMe3-n (OR') n , 1 ≤ n ≤ 3 with R = alkyl or aryl) have found various applications in synthetic chemistry and materials science because the silicon-bound alkoxy groups provide unique opportunities for further derivatization and transformations. Among the few catalytic strategies that allow the direct and intermolecular introduction of an alkoxysilyl unit onto an organic substrate, the alkoxysilylation of unactivated C-H bonds has barely been achieved despite its synthetic potential and the atom-economy it conveys. In particular, a catalytic and transition metal-free C-H silylation protocol towards this class of organosilicon compounds has yet to be reported. We herein describe the first general alkoxysilylation of (hetero)arene C(sp2)-H and benzylic C(sp3)-H bonds under ambient, transition metal-free conditions using newly-prepared tert-butyl-substituted alkoxysilyldiazenes (tBu-N[double bond, length as m-dash]N-SiMe3-n (OR') n , 1 ≤ n ≤ 3 with R' = Et, iPr or tBu) as silylating reagents and tBuOK as catalytic promoter.

Site-Selective Nitration of Aryl Germanes at Room Temperature

We report a site-selective ipso-nitration of aryl germanes in the presence of boronic esters, silanes, halogens, and additional functionalities. The protocol is characterized by operational simplicity, proceeds at room temperature, and is enabled by [Ru(bpy)3](PF6)2/blue light photocatalysis. Owing to the exquisite robustness of the [Ge] functionality, nitrations of alternative functional handles in the presence of the germane are also feasible, as showcased herein.