Directing group-assisted selective C–H activation of six-membered N-heterocycles and benzo-fused N-heterocycles

Abstract

Directing group-assisted selective C–H bond activation of six-membered N-heterocycles and benzo-fused N-heterocycles has been reported.

Advancement in the C–H bond alkylation of (hetero)arenes catalyzed by the most abundant transition metal–iron

“…The transition metal-catalyzed C2 alkylation of indoles is generally achieved through the chelation-assisted strategy. 11,94 Various 3d metals, such as Mn, 113 Co, 37,114,115 and Ni, 116–118 have been employed for the C2 alkylation of indoles. The first precedent of iron-catalyzed alkylation indoles via hydroarylation involving an iron/(NHC) catalytic system was reported by Yoshikai (Scheme 20).…”

“…Nevertheless, the regioselective activation of a single C–H bond in the presence of many other C–H bonds holds the key, and it has been addressed by introducing a Lewis base directing group on the substrate. 4–11 A range of directing groups (chelating motifs) such as pyridinyl, pyrazolyl, oxazolyl, amide, ether, and carbonyl have been utilized to demonstrate the versatility of this strategy. In the past two decades, using this chelation-assisted approach, several C–C bond-forming functionalizations such as alkylation, arylation, alkenylation, alkynylation, and various C–X (X = O, S, N, B, etc .)…”