Synlett, Table of Contents Synlett 2012; 23(20): 2961-2964DOI: 10.1055/s-0032-1317685 letter © Georg Thieme Verlag Stuttgart · New YorkIron(II)-Catalyzed Denitration Reaction: Synthesis of 3-Methyl-2-arylimidazo[1,2-a]pyridine Derivatives from Aminopyridines and 2-Methylnitroolefins Authors Author Affiliations Hao Yan State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. of China Fax: +86(931)8912582 Email: hgs@lzu.edu.cn Sizhuo Yang State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. of China Fax: +86(931)8912582 Email: hgs@lzu.edu.cn Xiai Gao State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. of China Fax: +86(931)8912582 Email: hgs@lzu.edu.cn Kang Zhou State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. of China Fax: +86(931)8912582 Email: hgs@lzu.edu.cn Chao Ma State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. of China Fax: +86(931)8912582 Email: hgs@lzu.edu.cn Rulong Yan* State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. of China Fax: +86(931)8912582 Email: hgs@lzu.edu.cn Guosheng Huang* State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. of China Fax: +86(931)8912582 Email: hgs@lzu.edu.cn Recommend Article Abstract Buy Article(opens in new window) All articles of this category(opens in new window) Abstract A variety of ways to synthesize imidazo[1,2-a]pyridines have been reported and many approaches are devoted to the functionalization of imidazo[1,2-a]pyridines. However, the use of a denitration reaction in the synthesis of imidazo[1,2-a]pyridines has not been reported. We report here the iron-catalyzed synthesis of 3-methyl-2-arylimidazo [1,2-a] pyridine derivatives from aminopyridines and 2-methyl-nitroolefins. The procedure, using FeCl2 as catalyst, is simple and inexpensive. Various functional groups are tolerated and provide the products in good yields. Key words Key wordsiron catalysis - denitration - heterocycles - cyclization - imidazo[1,2-a]pyridines Full Text References References and Notes 1a Chattopadhyay B, Gevorgyan V. Angew. Chem. Int. Ed. 2012; 51: 862 1b Burchak ON, Mugherli L, Ostuni M, Lacapere JJ, Balakirev MY. J. Am. Chem. Soc. 2011; 133: 10058 1c Bonne D, Dekhane M, Zhu JP. Angew. Chem. Int. Ed. 2007; 46: 2485 1d Zhou HY, Zhang W, Yan B. J. Comb. Chem. 2010; 12: 206 1e Wei HL, Yan ZY, Niu YL, Li GQ, Liang YM. J. Org. Chem. 2007; 72: 8600 1f Jiang B, Rajale T, Wever W, Tu SJ, Li GG. Chem.–Asian J. 2010; 5: 2318 1g Hong D, Zhu YX, Li Y, Lin XF, Lu P, Wang YG. Org. Lett. 2011; 13: 4668 1h Basso A, Banfi L, Riva R. Eur. J. Org. 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After the solvent was evaporated in vacuo, the residues were purified by column chromatography, eluting with PE–EtOAc to afford pure 3aa (57 mg, 80%) as a white solid; mp 140–142 °C. 1H NMR (400 MHz, CDCl3): δ = 7.78–7.84 (m, 3 H), 7.62 (d, J = 9.2 Hz, 1 H), 7.45 (t, J = 7.6 Hz, 2 H), 7.31–7.34 (m, 1 H), 7.11–7.15 (m, 1 H), 6.78 (t, J = 6.8 Hz, 1 H), 2.58 (s, 3 H). 13C NMR (100 MHz, CDCl3): δ = 144.2, 142.2, 134.7, 128.3, 128.2, 127.2, 123.3, 122.7, 117.2, 115.7, 111.8, 9.45. IR (neat): 3066, 3030, 2918, 1501, 1354, 1246, 773, 753, 700 cm–1. HRMS (ESI): m/z [M + H]+ calcd for C14H13N2: 209.1073; found: 209.1077. Supplementary Material Supplementary Material Supporting Information (PDF)
