Deprotonation of pyridine carboxamides using lithium magnesiates bases

Regioselective deprotonation of N-methyl- and tert-butylpyridine carboxamides using lithium magnesiates bases was achieved at room temperature avoiding nucleophilic addition on the pyridine molecule and auto-condensation of the arylmetal intermediates on the amide group was described. The hydrogen-magnesium exchange was evidenced using 1H NMR spectroscopy at room temperature and the reactivity of the lithium 2-, 3- and 4-carboxamidopyridinylmagnesiates complexes towards electrophiles and in cross-coupling reactions was studied.