61532-32-9Relevant academic research and scientific papers
Microwave-Assisted C-2 Direct Alkenylation of Imidazo[4,5-b]pyridines: Access to Fluorescent Purine Isosteres with Remarkably Large Stokes Shifts
Baladi, Tom,Granzhan, Anton,Piguel, Sandrine
, p. 2421 - 2434 (2016/06/01)
We describe herein the first C-2 direct alkenylation of the valuable 3H-imidazo[4,5-b]pyridine promoted by microwave-assisted Pd/Cu co-catalysis. The reaction is rapid and compatible with a wide range of functional groups either on the imidazo[4,5-b]pyridine ring or on the styryl bromides thereby leading to the isolation of 23 compounds with moderate to good yields. The relevance of this method is demonstrated by its application to the synthesis of new cross-conjuguated push-pull 2-vinyl- and 2-alkynylimidazo[4,5-b]pyridines characterized by satisfactory fluorescence quantum yields and remarkable solvatofluorochromic properties.
Palladium-Catalyzed Suzuki Cross-Coupling of 2-Halo-Deazapurines with Potassium Organotrifluoroborate Salts in the Regioselective Synthesis of Imidazo[4,5-b]pyridine Analogues
Savitha, Bhaskaran,Sajith, Ayyiliath. M.,Joy, M. Nibin,Khader, K.K. Abdul,Muralidharan,Padusha, M. Syed Ali,Bodke, Yadav D.
, p. 618 - 630 (2016/07/06)
In this paper, we report the use of potassium organotrifluoroborate salts as nucleophilic organoboron reagents in the Suzuki cross-coupling reactions of 2-halo deazapurines. Regio-isomeric C-2-substituted imidazo[4,5-b]pyridine analogues were synthesized by employing this protocol in good to excellent yields. Whereas aryl and heteroaryl trifluoroborates reacted readily to give the coupled products in high yields, alkyltrifluoroborates were found to be less reactive. The utilization of tetrabutylammonium acetate was found to play a substantial role in enhancing the reaction rates of the cross-coupling process. Also, a comparative study was performed between boronic acids and potassium organotrifluoroborate salts.
Rapid construction of imidazopyridines from ortho-haloaminopyridines
Li, Chaomin,Chen, Lily,Steinhuebel, Dietrich,Goodman, Andrew
supporting information, p. 2708 - 2712 (2016/06/09)
A practical strategy for the preparation of imidazopyridine derivatives from ortho-haloaminopyridines utilizing a two-step C-N coupling/cyclization reaction sequence has been developed. This procedure provides rapid and efficient access to many medicinally interesting imidazopyridine compounds and related imidazopyrazine/purine heterocycles.
Facile, regioselective syntheses of N-alkylated 2,3-diaminopyridines and imidazo[4,5-b]pyridines
Khanna,Weier,Lentz,Swenton,Lankin
, p. 960 - 965 (2007/10/02)
Useful strategies are reported for the differentiation and selective synthetic manipulations of amino groups at the 2- and 3-positions of pyridines. It has been found that 2,3-diaminopyridine reacts with aldehydes under reductive amination conditions to g
Ethoxymethylenemalonates and Malononitriles (EMM reagents) as formic acid equivalents: Synthesis of fused-imidazoles under neutral or mildly acidic con
Segelstein, Barb E.,Chenard, Bert L.,Macor, John E.,Post, Ronald J.
, p. 1897 - 1900 (2007/10/02)
The use of ethoxymethylenemalonates and malononitriles (EMM reagents) for the efficient synthesis of fused imidazoles and related compounds is describe.
