An efficient access to 2,3-diarylimidazo[1,2-a]pyridines via imidazo[1,2-a]pyridin-2-yl triflate through a Suzuki cross-coupling reaction-direct arylation sequence

9,11,12,14‐Tetraaryldibenzo[f,h]imidazo[1,2‐b]isoquinolines and Their Emission Responses to Solvent Polarity, Acidity, and Nitroarenes

“…When 1,3-diphenyl-2H-cyclopenta[l]phenanthren-2-one (1), benzil (2a), and ammonium acetate were mixed in acetic acid and allowed to react at 80°C for 10 h, a yellow solid, 3a, could be isolated. Through single-crystal analysis, the structure of 56 3a was identified as 9,11,12,14- Figure S1), [21] which was further confirmed by 1 H NMR, 13 C NMR, and HRMS analyses. Promoted by this unusual structure and intrigued by its mechanism of formation, we optimized the reaction condi-61 tions by using 1 and 2a as substrates; the results are summarized in Table 1.…”

“…[11][12][13] Although other synthetic methods have also been designed, [14,15] such strategies are limited by 31 the availability of starting materials, such as 2-aminopyridine derivatives and chloroacetaldehydes, because of their difficult preparation. As part of our ongoing research on fluorescent structure-property relationships [16,17] and synthetic materials for 36 organic light-emitting diodes, [18,19] we were interested in developing more efficient strategies for the construction of fully arylated imidazo [1,2-a]pyridines.…”

Synthesis of Imidazo[1,2‐a]pyridines and Imidazo[2,1‐b]thiazoles Attached to a Cycloalkyl or Saturated Heterocycle Containing a Tertiary Hydroxy Substitution

“…Few papers describe the synthesis of related hydroxyl substituted imidazo[1,2‐ a ]pyridines, imidazo[2,1‐ b ]thiazoles, and benzo[ d ]imidazo[2,1‐ b ]thiazoles, but only dimethyl groups were explored as the alkyl groups in these reports (Fig. ) .…”

“…An alternative method could be possible if a Grignard reagent, prepared from the 2‐bromoimidazo[1,2‐ a ]pyridine, is added to a cyclo alkanone (Fig. , Method D) . This would yield the required products, but the reported synthesis of the Grignard precursors 2‐bromoimidazo[1,2‐ a ]pyridine and 6‐bromoimidazo[2,1‐ b ]thiazole is difficult and also low yielding (Fig.…”

N,N,N′,N′‐Tetrabromobenzene‐1,3‐disulfonamide and Poly(N‐bromo‐N‐ethylbenzene‐1,3‐disulfonamide) as Mild and Efficient Catalysts for Solvent‐free Synthesis of N‐Cyclohexyl‐2‐aryl(alkyl)‐imidazo[1,2‐a]pyridin‐3‐amine Derivatives

“…Imidazo[1,2‐ a ]pyridines have been shown to possess a broad range of biological activities and have been investigated for treatment of conditions such as gastric disease , heart diseases , migraines , viral diseases , HIV‐1 inhibitors , and activity against the colon cancer cell lines HT‐29 and Caco‐2 . The most common route for the preparation of imidazo[1,2‐ a ]pyridines involves the condensation of o ‐aminopyridine, aldehydes, and isocyanides in the presence of a catalyst . However, some of these condensations have some demerits such as the requirement of expensive and excess amount of catalyst, longer time, difficulties in work‐up procedure, and harsh reaction conditions .…”