Iron-promoted sulfur sequestration for the substituent-dependent regioselective synthesis of tetrazoles and guanidines

ABSTRACT

We have established a facile and versatile synthetic methodology for the construction of tetrazoles and guanidines in the presence of an eco-friendly, inexpensive, easily available iron reagent. Aromatic thioureas with electron-donating substituents produced their respective target products in quantitative yield. In contrast, when electron-withdrawing substituted aromatic thioureas were used, the expected products were obtained in reduced yield. However, the desired products were obtained in good yield at moderate temperature. In addition, mechanistic studies revealed that the synthetic route involved iron-based subsequent reactions of addition and removal of sulfur.

GRAPHICAL ABSTRACT

KEYWORDS:

• Sulfur-extracting reagent iron
• room temperature
• tetrazoles
• guanidines
• desulfurization

Disclosure statement

No potential conflict of interest was reported by the author(s).