Chemical transformation of tetraacetal tetraoxa-cages to aza-cages and amido-cages mediated by iodotrimethylsilane and the combination of chlorotrimethylsilane and sodium iodide in nitriles

Article abstract of DOI:10.1016/S0040-4020(98)00277-4

An one-pot conversion of tetraacetal tetraoxa-cages 1a-e to aza-cages 2a-e mediated by iodotrimethylsilane in alkyl nitriles at 25 °C via the ring expansion compound 9 as the reaction intermediate was discovered. A Ritter- type reaction was proposed for the mechanism of this conversion. On the other hand, reaction of tetraacetal tetraoxa-cages 1 with Me₃SiCl and NaI in nitriles at 25 °C gave the amido-cages 12. Conjugated nitriles and Lewis acids, such as TiCl₄ or BF₃-OEt₂ were found to be ineffective for the conversion of oxa-cages to aza-cages. The structures of 2a and chemical transformation product 16 were proven by X-ray analysis.