I₂-Catalyzed Oxidative Cross-Coupling Reaction of Methyl Ketones and 2-(2-Aminophenyl) Benzimidazole: Facile Access to Benzimidazo[1,2-c]quinazoline

Abstract

A general and efficient iodine-catalyzed metal-free oxidative cross-coupling reaction of methyl ketones with 2-(1 H -benzo[ d ]imidazol-2-yl)aniline has been established. This is a new synthetic strategy for the synthesis of benzimidazo[1,2- c ]quinazoline derivatives involving C(sp 3 )–H oxidation, condensation, and cyclization processes.

Iodine and DMSO as Surrogate of Hazardous Metal and Non‐Metal Reagents in Organic Synthesis

“…Similarly, Ambethkar et al used the acetophenone derivatives to cyclize with 2-(1Hbenzo[d]imidazol-2-yl) aniline as model substrate to access the benzimidazo [1,2c]quinazolines (Scheme 78 (c)). [780] A catalytic amounts of iodine (20 mol%) afforded the desired scaffolds in a quite appreciable amounts. The process was found to be very sensitive to the proposed reaction conditions.…”

I2/DMSO-mediated oxidative C–C and C–heteroatom bond formation: a sustainable approach to chemical synthesis

“…Padmini and coworkers 45 prepared benzoimidazoquinazoles 25 derivates in a straightforward, one-pot, metal-free, effective new reaction methodology using the combination of I 2 and DMSO. The developed technique can be considered feasible due to the fact that the I 2 /DMSO catalyst facilitates the oxidative amination of the C–H bond in ketones 4, resulting in favourable yields.…”

“…44 Furthermore, it provides the advantage of the selective oxidation of alcohol to carbonyl or carboxylic acid. However, the application of H 2 O 2 as an external oxidant reduces the amount of I 2 reconverting iodide, whereas the addition of TBHP (tert-butyl hydroperoxide) to I 2 /DMSO provides opportunities to obtain various signicant compounds such as benzimidazo [1,2-c]quinazolines [45][46][47] and amidation. 7,48 In general, the reaction mechanism of I 2 /DMSO is straightforward and unambiguous.…”

Arene Ruthenium(II)-Catalyzed Sustainable Synthesis of 2,4-Disubstituted Quinazolines via Acceptorless Dual Dehydrogenative Coupling of Alcohols

“…Among them, the synthetic approach involves the transition-metal-catalyzed cyclization reaction of 2-halobenzyl halides or tosylates with amines, aldehydes, and azides . Further reports are available on amidines that underwent oxidative cyclization reaction with 2-carbonyl halobenzenes, aldehydes, and alkynes …”