CONDENSATION OF 2-PYRIDYLMETHYLLITHIUM NUCLEOPHILES AND PYRIDINE ELECTROPHILES AS A CONVENIENT SYNTHETIC ROUTE TO POLYDENTATE CHELATING N-DONOR LIGANDS
Keywords:
4-tert-butylpyridine, dipyridinemethanes, 2,6-lutidine, (6-methyl-2-pyridyl)methyllithium, 2-picoline, pyridine, 2-pyridylmethyllithium, tripyridinedimethanes, C–C bond cleavage, DFT calculations, condensation, free Gibbs reaction energy, nucleophilic substitutionAbstract
Condensation of 2-pyridylmethyllithium or (6-methyl-2-pyridyl)methyllithium nucleophiles and pyridine, 2-picoline or 4-tert-butylpyridine as electrophiles leads to new polydentate N-donor ligands, methyl-, tert-butylsubstituted tripyridinedimethanes or to tripyridinedimethane itself, in good or high yields. Depending on the reagent ratio, solvent used and reaction condition corresponding intermediate dipyridinemethanes can be minor by-product or major products of the condensation. In contrast to 2-pyridylmethyllithium, lithiated 2-isopropylpyridine does not react with pyridine electrophiles. Vice versa, nucleophilic substitution at C(2)-pyridine carbon of 2,2-bis(2-pyridyl)propane with 2-pyridylmethyllithium takes place to produce products of condensation of 2-isopropylpyridine and dipyridylmethyllithium. DFT calculations of the reactions Gibbs free energies combined with pKa values of the CH-acids involved help to explain the reactivity observed.
How to Cite
Vedernikov, N.; Miftakhov, R.; Borisoglebski, S. V.; Caulton, K. G.; Solomonov, B. N. Chem. Heterocycl. Compd. 2002, 38, 406. [Khim. Geterotsikl. Soedin. 2002, 471.]
For this article in the English edition, see DOI https://doi.org/10.1023/A:1016023103898
