Translation of pseudo-cross-conjugation into chemistry: cycloadditions of mesomeric betaines to the new ring system spiro[indazole-3,3'-pyrrole].
Indazolium-3-amidates (X-ray analysis), readily available on trapping the N-heterocyclic carbene indazol-3-ylidene with isocyanates, underwent [3+2]-cycloadditions with activated triple bonds to spiro[indazole-3,3'-pyrroles]. A combination of NMR techniques such as heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond correlation (HMBC), nuclear Overhauser enhancement spectroscopy (NOESY), and 1H/15N correlations were applied to elucidate the structures of the cycloadducts.
Schmidt
Andreas
A
Institute of Organic Chemistry, Leibnizstrasse 6, Clausthal University of Technology, D-38678 Clausthal-Zellerfeld, Germany. schmidt@ioc.tu-clausthal.de
Habeck
Tobias
T
Lindner
Anika Sabine
AS
Snovydovych
Bohdan
B
Namyslo
Jan Christoph
JC
Adam
Arnold
A
Gjikaj
Mimoza
M