Synthesis of 2,3-diaminodihydropyrroles via thioimidate cyclopropane rearrangement

The synthesis of novel 2,3-diaminodihydropyrroles is reported. The key step is a thiomethylimidate cyclopropane rearrangement to afford a pyrrolothiomethylimidate intermediate. Reaction of this intermediate with amines produced the title compounds in good yields. The scope and mechanism of the reaction is discussed.