A multi pathway coupled domino strategy: I₂/TBHP-promoted synthesis of imidazopyridines and thiazoles via sp³, sp² and sp C–H functionalization

Abstract

One-pot, multi-pathway, and atom economic synthesis of imidazoles and thiazoles has been achieved. In the catalytic system, I2/TBHP as an initiator and oxidant is used to realize sp3, sp2 and sp C–H functionalization.

Palladium-Catalyzed Regioselective C3-Allylic Alkylation of 2-Aryl Imidazopyridines with MBH Carbonates

“…All the imidazopyridine derivatives were prepared using previous literature precedent, and characterization data of the compounds such as 1a , 1b , 1c , 1d , 1e , 1f , 1g , 1h , 1j , 1k , 1l , 1m , and 1n were found to match with previous reports.…”

I2-Catalyzed Oxidative Acylation of Tertiary Amines via C–N Bond Cleavage

“…The formation of the radical intermediate A via C-H activation is consistent with the speculation of previous research. 25 Subsequently, intermediate A underwent coupling with HO • to generate hemiaminal B, which eliminates a molecule of formaldehyde to give N-methylaniline (C). Finally, intermediate C is acylated by 1a to generate the amide product 3a.…”

Access to 2,3‐Unsubstituted Imidazo[2,1‐b][1,3]benzothiazole Using Ethylene Glycol as a C2 Precursor and Subsequent Regioselective C3 Functionalization

“…[15] Following the general procedure, after 16 h, 3 a was isolated as a colorless liquid in 57 % yield (40 mg). 1 H NMR (400 MHz, CDCl 3 ): δ 7.72 (d, J = 8.4 Hz, 1H), 7.62 (d, J = 8 Hz, 1H), 7.49-7.45 (m, 1H), 7.44 (s, 1H), 7.39-7.33 (m, 1H); 13 C { 1 H} NMR (100 MHz, CDCl 3 ): 147.8, 134.5, 132.1, 130.6, 126.1, 124.9, 124.4, 112.7, 111.5.…”