Heteroarylation of Congested α-Bromoamides with Imidazo-Heteroarenes and Indolizines via Aza-Oxyallyl Cations: Enroute to Dibenzoazepinone and Zolpidem Analogues

Abstract

Herein, we report a highly efficient and unprecedented approach for heteroarylation of congested α-bromoamides via electrophilic aromatic substitution of imidazo-heteroarenes and indolizines under mild reaction conditions (room temperature, metal, and oxidant free). The participation of an in situ generated aza-oxyallyl cation as an alkylating agent is the hallmark of this transformation. The method was readily adapted to synthesize novel imidazo-heteroarene-fused dibenzoazepinone architectures of potential medicinal value.

Synthesis and site selective C–H functionalization of imidazo-[1,2-a]pyridines

“…Furthermore, the formation of a C(sp 2 )–C(sp 3 ) bond involves the use of a reactivity toolbox of aza-oxyallyl cations (Scheme 33). 84…”

“…Furthermore, the formation of a C(sp 2 )-C(sp 3 ) bond involves the use of a reactivity toolbox of aza-oxyallyl cations (Scheme 33). 84 Soon after this, one year later, the Hajra group published the first report of a visible light-mediated metal-free carbon-…”

Heteroannulation of Arynes with Bromodifluorohydroxamates: An Efficient and General Approach to Access 2,2-Difluoro Indoxyls

“…13 C { 1 H} NMR (126 MHz,CDCl3) δ 183.1 (t, J = 21.5 Hz), 157.2, 152.2 (t, J = 5.2 Hz), 135. 6,129.7,129.0,128.7,128.2,118.5 (t,J = 301.8 Hz),116.1,105.4,79.45,55.8. 19 F NMR (471 MHz, CDCl3) δ -108.2.…”

“…Reaction mixture was then heated using oil bath at 110 ο C for 6 h. After completion of starting material followed with TLC, reaction was then quenched with water and extracted with EtOAc and further purified over silica gel to obtained desired product 3ag' (16 mg, 65% yield). 6 Analytical Data of compound 3ag'…”