Photoredox-Catalyzed Site-Selective Generation of Carbanions from C(sp <sup>3</sup> )–H Bonds in Amines
Kathiravan Murugesan, Karsten Donabauer, Rok Narobe, Volker Derdau, Armin Bauer, Burkhard König
Abstract
The selective activation of sp3 carbon–hydrogen bonds in the presence of multiple C–H bonds is challenging and remains of supreme importance in chemical research. Late-stage modification of complex molecules via sp3 C–H activation is of high prevalence in organic synthesis. Herein, we describe the activation of a C(sp3)–H bond in the α-position to an amine via a carbanion intermediate. In the presence of several α-amine sites, only one specific position is selectively activated. Applying this protocol, the proposed carbanion intermediate was effectively trapped with different electrophiles such as deuterium (D+), tritium (T+), or carbonyl compounds compiling over 50 examples. Further, this methodology was used to install deuterium or tritium in different drug-derivatives (>10 drugs) at a selected position in a late-stage functionalization. In addition, the protocol is suitable for a gram-scale synthesis, and a detailed mechanistic investigation has been carried out to support our hypothesis.