New cyrhetrenyl and ferrocenyl sulfonamides: Synthesis, characterization, X-ray crystallography, theoretical study and anti-Mycobacterium tuberculosis activity

A new series of cyrhetrenyl and ferrocenyl sulfonamides were designed, synthesized and characterized. The reactions of organometallic amines (P2 and P3) with the corresponding arylsulfonyl chlorides produced cyrhetrenyl (2a-c) and ferrocenyl (3a-c) sulfonamide derivatives. All the compounds were characterized by conventional spectroscopic techniques (FT-IR, ¹H and ¹³C NMR and mass spectrometry). The proposed molecular structures of 2a and 3a were confirmed by single-crystal X-ray crystallography. Theoretical calculations at the DFT level were also carried out as an approximation to rationalize the influences of the electronic natures of the organometallic fragments into the sulfonamide skeleton. All the complexes were screened in vitro against Mycobacterium tuberculosis and exhibited only modest activities in the micromolar range.