Transition-metal-free silylboronate-mediated cross-couplings of organic fluorides with amines

C-N bond cross-coupling is fundamental in organic chemistry, but the readily available organic fluorides are unsuitable as coupling substrates. Here, we realize defluorinative cross-coupling with amines via a silylboronate-mediated strategy. C-N bond cross-couplings are fundamental in the field of organic chemistry. Herein, silylboronate-mediated selective defluorinative cross-coupling of organic fluorides with secondary amines via a transition-metal-free strategy is disclosed. The cooperation of silylboronate and potassium tert-butoxide enables the room-temperature cross-coupling of C-F and N-H bonds, effectively avoiding the high barriers associated with thermally induced S(N)2 or S(N)1 amination. The significant advantage of this transformation is the selective activation of the C-F bond of the organic fluoride by silylboronate without affecting potentially cleavable C-O, C-Cl, heteroaryl C-H, or C-N bonds and CF3 groups. Tertiary amines with aromatic, heteroaromatic, and/or aliphatic groups were efficiently synthesized in a single step using electronically and sterically varying organic fluorides and N-alkylanilines or secondary amines. The protocol is extended to the late-stage syntheses of drug candidates, including their deuterium-labeled analogs.

Automated summary

Defluorinative cross-coupling between amines and organic fluorides is achieved via a silylboronate-mediated strategy. This method enables the room-temperature cross-coupling of C-F and N-H bonds, avoiding the high energy barriers associated with thermally induced S(N)2 or S(N)1 amination. The selective activation of the C-F bond of organic fluorides by silylboronate is a significant advantage of this transformation.