Translation of pseudo-cross-conjugation into chemistry: Cycloadditions of mesomeric betaines to the new ring system spiro[indazole-3,3'-pyrrole]

Indazolium-3-amidates have undergone [3+2]-cycloadditions with activated triple bonds to spiro[indazole-3,3'-pyrroles]. Heternuclear single quantum coherence (HSQC), heteronuclear multiple bond correlation (HMBC), nuclear Overhauser enhancement spectroscopy (NOESY) and [super 1]H/[super 15]N correlations are used to examined the structures of the cycloadducts.