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We have synthesized a series of chiroporphyrins in which the ester functions on adjacent meso substituents are linked by a bridle of adjustable length. The ruffled distortion induced by the α, β, α, β alternation of the porphyrin meso substituents can be controlled by the length of the bridles. X-ray structure determinations show that intermolecular constraints within the crystalline network can stabilize conformers that considerably differ from the mean conformation observed in solution by 1H–NMR. To cite this article: S. Gazeau et al., C. R. Chimie 5 (2002) 27–31 [Copyright &y& Elsevier]

We wish to propose a novel chiral shift reagent for the determination of enantiomer composition of amino acid derivatives. This reagent, chlorocobalt(III) tetramethylchiroporphyrin CoCl(TMCP), effects quantitative in situ derivatization of amino compounds in the NMR tube, without any detectable kinetic resolution. The influences of the chiral cavity and of the porphyrin ring current on the signals of the coordinated amino acid methyl ester L* can be seen in the high-field region of the 1H NMR spectrum of the bis-adduct [Co(L*)2(TMCP)]+Cl–. The signatures of the (R) and (S) ligands are well resolved at 200 MHz, and their relative intensities can be readily determined by peak integration. To cite this article: M. Claeys-Bruno et al., C. R. Chimie 5 (2002) 21–25 [Copyright &y& Elsevier]