Inorganic Chemistry

Heterocyclic Hypervalent Iodine(III) Compounds with Fused Benziodazole and Tetrazole Rings (I-Substituted Tetrazolo[1,5-b][1,2]Benziodazoles)

Authors

Abstract

A series of heterocyclic hypervalent (HV) iodine(III) compounds containing fused tetrazole and benziodazole rings, i.e., derivatives of benziodazolotetrazole (BIAT) with various ligands attached to the iodine atom were prepared and studied. BIAT-Cl was synthesized via chlorination of 5-(2-iodophenyl)-1H-tetrazole and subsequent spontaneous cyclo-dehydrochlorination of the initially formed dichloroiodo compound. The oxidation of the aforementioned parent monovalent iodine substrate with NaIO4 yielded BIAT-OH, which was in turn reacted with acetic anhydride to afford the I-acetoxy derivative BIAT-OAc. BIAT-OMe was obtained by refluxing the latter compound or by dissolving (2-(1H-tetrazol-5-yl)phenyl)(hydroxy)iodonium tosylate in methanol. All heterocyclic HV iodine(III) compounds were characterized by 1H and 13C NMR spectroscopy, ESI-HRMS, and single crystal X-ray crystallography. The reaction of alkenes with BIAT-Cl in the presence of Cu(OTf)2 at room temperature afforded chloro-tetrazolylated products in 70-88% isolated yields. The oxidation of thioanisole with BIAT-Cl under various reaction conditions is also reported. The thermal stabilities of all BIAT derivatives were examined as well. The enthalpies of exothermic degradation were measured by thermal gravimetric analysis coupled with differential scanning calorimetry and were determined to be in the range between −35.3 and −305.3 kJ mol-1, i.e., significantly larger than the enthalpy of decomposition (−29.4 kJ mol-1) of the parent monovalent iodine-containing tetrazole – 5-(2-iodophenyl)-1H-tetrazole.

Version notes

Thermal analysis section - enthalpies of decomposition, and synthetic procedures have been updated.

Content

Thumbnail image of Heterocyclic HVI(III) Compounds with Fused Benziodazole and Tetrazole Rings - ChemRxiv v. 2.pdf

Supplementary material

Thumbnail image of Heterocyclic HVI(III) Compounds with Fused Benziodazole and Tetrazole Rings -SI-ChemRxiv v. 2.pdf
Heterocyclic HVI(III) Compounds with Fused Benziodazole and Tetrazole Rings -SI-ChemRxiv v. 2
Supporting Information ChemRxiv v2
Thumbnail image of BIAT-Cl (3 mg) themal decomposition.mov
BIAT-Cl (3 mg) themal decomposition
BIAT-Cl (3 mg) themal decomposition
Thumbnail image of BIAT-Cl (3 mg) rxn with Bu3P and DMSO.mov
BIAT-Cl (3 mg) rxn with Bu3P and DMSO
BIAT-Cl (3 mg) rxn with Bu3P and DMSO