Generation of oxodiazonium ions 6. Unexpected formation of tetrazole 1-oxides

(E)-2-[2,2-Bis(tert-butyl-NNO-azoxy)-1-(methylsulfinyl)vinyl]-1-isopropoxydiazene 1-oxide reacts with boron trifluoride etherate (BF(3)aEuro cent Et2O) producing 2-tert-butyl-N-nitro-2H-tetrazolo-5-carboxamide 4-oxide and 2-tert-butyl-2H-tetrazolo-5-carbonitrile 4-oxide but not the expected 1,2,3,4-tetrazine 1,3-dioxide derivative. This reaction direction can be explained by cationic domino cyclization, the key stage of which is coupling of the oxodiazonium ion with the geminal MeS(O) group. Structure of N-nitrocarboxamide was confirmed by X-ray diffraction analysis.