Jiří Závada

Optically pure (S)- and (R)-4,5-dihydro-3H-4-methyldinaphth[2,1-c; 1', 2'-e]azepines. Application to the synthesis of new bidentate ligands with axial asymmetry

Abstract Easily available ephedrinium salts (S,1R,2S)- and (R,1R,2S)-2 on treatment with alkoxide base afford enantiomerically pure dihydroazepines (S)- and (R)-1, respectively, in quantitative yields. Cleavage of the corresponding dihydroazepinium quaternary salts (S)- and (R)-4 with N- and S-nucleophiles provides a simple approach to a new series of 1,1′-binaphthalene ligands with two different donor groups in 2,2′-positions.

Nucleophilic coupling of alkali 2-naphthoxides with 1-bromo-2 naphthols. Ion-pairing and halogen dance in the formation of 1,1′-binaphthalene-2,2′-diols

A very pronounced effect of solvent and cation has been found in the investigated reaction, indicating that ion-pairing is indispensable in the title product formation. A simple rationale has been provided assuming self assembly of the complementary reactants driven by hydrogen bonding and ion-pairing interactions. Concomitantly, halogen exchange between the reaction partners has been demonstrated to be a concurrent pathway, resulting from the nucleophilic 2-naphthoxide attack at the bromine terminus of the Cα–Br bond in the participating 1-bromo-2-naphthol.

Rearrangement of 1,3-bis(azacrown)-2-chloropropanes: the effect of alkali metal ion on neighbouring group participation

A pronounced effect of alkali metal ion on rate and product distribution has been found in the reaction of the twelve-, fifteen- and eighteen-membered 1,3-bis(azacrown)-2-chloropropanes 1a–c with benzyl oxide–benzyl alcohol base–solvent system.

A new type of functionalized cryptand-like ionophore. Synthesis, structure and complexation

New functionalized cryptand-like ionophores are prepared from appropriate diaza-crown ethers and epichlorohydrin, using FAB MS, potentiometry, 13C-NMR spectroscopy, and T1 relaxation times measurements, the conformation and complexation patterns are found to change dramatically with the change in size of the macrocycle.