The amino acid Schiff base manganese complex (Tryp–Mn); 1, was prepared with L-tryptophan, salicylaldehyde and Mn(OAc)2.4H2O in methanol. In the presence of 1, 1,4-dihydropyridines (1,4-DHPs) were oxidised by n-Bu4NIO4 to the corresponding pyridine derivatives in high yields. Imidazole was used as an additive to improve the catalytic oxidation.
(a) OikeM., InoueY., KitamuraK., and KuriyamaH., Circ. Res., 1990, 67, 993; (b) A. Takahara, S. Fujita, K. Moki, Y. Ono, H. Koganei, S. Wayama and H. Yamamoto, Hypertens. Res., 2003, 26, 743.
3.
MarchalinS., BaumlovaB., BaranP., OulyadiH., and DaichA., J. Org. Chem., 2006, 71, 9114.
KarimipourG.R., MontazerozohooriM., and KaramiB., J. Chem. Res (S), 2006, 605.
18.
MohajerD., KarimipourG.R., and BagherzadehM., New J. Chem., 2004, 28, 740.
19.
(a) LiuJ.Y., LiX.F., LiY.Z., ChangW.B., and HuangA.J., J. Mol. Catal. A, 2002, 187, 163; (b) E. Baciocchi, T. Boschi, C. Galli, A. Lapi and P. Tagliatesta, Tetrahedron, 1997, 53, 4497; (c) K. Konishi, K. Oda, K. Nishida, T. Aida, and S. Inoue, J. Am. Chem. Soc., 1992, 114, 1313; (d) R.L. Halterman and S.T. Jan, J. Org. Chem., 1991, 56, 5253; (e) J.P. Battioni, D. Dupre and D. Mansuy, J. Organomet. Chem., 1987, 328, 173; (f) D. Mansuy, Pure Appl. Chem., 1987, 59, 759; (g) E. Guilmet and B. Meunier, Tetrahedron Lett., 1982, 23, 2449; (h) E. Guilmet, B. Meunier, Nouv. J. Chim., 1982, 6, 511.
