Sulfonyl Triazoles as Stable Carbene Precursors

As already mentioned, 1,2,3-triazoles are very stable heterocycles. However, those that bear a strong electron-withdrawing group at N1 are known to undergo ring-chain tautomerization. The ring-chain isomerism of 1 -sulfonyl 1,2,3-triazoles can be exploited in synthesis. As reported recently, 1-sulfonyl triazoles could serve as 

Another example of the exquisite reactivity of rhodium(II) azavinyl carbenes is illustrated by their addition to olefins, which is a very facile process and proceeds 

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