On the reactions of tertiary carbanions with some nitroindazoles and nitrobenzotriazoles.

The vicarious nucleophilic substitution in some nitroindazole and nitrobenzotriazole derivatives with tertiary carbanions leads almost exclusively to products substituted para to the nitro group. As results from the theoretical calculations and structural evidences, such reaction outcome is due mainly to the stereoelectronic reasons in combination with the considerable shortening of the Cortho-CNO2 bond. The presence of the chiral and prochiral centres (the methine and N-methylene groups, respectively) often gives rise to additional splitting of the methylene protons signal that is transmitted on a long distance provided there is no pyridinic nitrogen in the pathway of coupling. [ABSTRACT FROM AUTHOR]