Qingqi Chen

AN EFFICIENT ONE-STEP CONVERSION OF BILIVERDINS TO 14-FORMYLTRIPYRRINONES

7. (a) H. -G. Korth, R. Sustmann, P. Lommes, T. Paul, A. Emst, H. de Groot, L. Hughes and K. U. Ingold, J. Am. Chem. SOC., 116,2767 (1994); @) D. W. Brown, P. R. Graupner, M. Sainsbury and H. G. Shertzer, Tetrahedron, 47,4383 (1991); (c) Y. L. Chen, J. Nielsen, K. Hedberg, A. Dunaiskis, S. Jones, L. Russo, J. Johnson, J. Ives and D. Liston, J. Med. Chem., 35,1429 (1992); (d) H. Sugimoto, Y. Iimura, Y. Yamanishi and K. Yamatsu, Bioorg. Med. Chem. Let?.., 2,871 (1992); (e) M. Masui, A. Ando and T. Shioiri, Tetrahedron Lett., 29,2835 (1988).

LARGE SCALE, EFFICIENT SYNTHESIS OF 9-UNSUBSTITUTED DIPYRRINONE

ABSTRACT 9-Unsubstituted dipyrrinone 8, the useful precursor for the synthesis of biliverdins, bilirubins, and other bile pigments, was synthesized in large scale and high yield starting from acetaldehyde and nitroethane in eight steps with overall yield 10%. The key intermediate 3,4-dimethyl-2-ethoxycarbonylpyrrole 3 was synthesized via Zard–Bartons method in high yield.

DOUBLY N-CONFUSED CALIX[4]PYRROLE PREPARED BY RATIONAL SYNTHESIS

ABSTRACT Doubly N-confused calix[4]pyrrole 4 is prepared in high yield by the [3 + 1] condensation of tripyrrane 3 with 2,4-dihdoxymethylpyrrole 2 under acid-catalysed conditions.

Fourier-transform Raman and infrared spectroscopic analysis of dipyrrinones and mesobilirubins

The Fourier-transform Raman (FT-Raman), infrared (FT-IR), and UV-visible absorption spectra of four dipyrrinones and two mesobilirubins have been investigated in the solid state and in CH2Cl2 solutions. A detailed spectral analysis, assignment and discussion of these spectra are presented. The bands at 1735-1738, 1691-1707 and 1359-1377 cm(-1) which were assigned to the stretching vibrations of the C-O-C and C-O-H and symmetric deformation of C-H bonds, respectively, can act as a marker to distinguish the compounds of this class. The striking differences between the spectra of the compounds suggest that mesobilirubin XIIIalpha is tending to adopt as ridge-tile conformation, rather than linear conformation.

Self-assembly of 1,4-bis(pyrrol-2-ylmethyleneamine)butane mediated by Ni(II) and weak intermolecular interactions

A complex [NiL] was prepared by the self-assembly of 1,4-bis(pyrrol-2-ylmethyleneamine)butane (H2L) with Ni(OAc)2·2H2O, its structure was elucidated by X-ray analysis and the weak intermolecular interactions play a crucial role in the molecular packing.

A facile, highly efficient synthesis of fully N-confused calix[5]pyrrole

ABSTRACT Fully N-confused calix[5]pyrroles 3 are prepared in high yield by the oligomerization of 3-hydroxyphenylmethylpyrrole 2 under acid-catalysed conditions at room temperature.