Nonafluorobutanesulfonyl Azide: A Shelf-Stable Diazo Transfer Reagent for the Synthesis of Azides from Primary Amines

Abstract

Nonafluorobutanesulfonyl azide is an efficient, shelf-stable and cost-effective diazo transfer reagent for the synthesis of azides from primary amines. The reagent can also be successfully applied to the one-pot regioselective synthesis of 1,2,3-triazoles from primary amines by a sequential diazo transfer and azide–alkyne 1,3-dipolar cycloaddition process catalyzed by copper. The cycloaddition step can be conducted in an inter- or intramolecular way to afford 1,4- or 1,5-disubstituted triazoles, respectively. The atypical 1,5-regioselectivity under copper catalysis is a consequence of geometrical constraints of the amino-alkyne substrates used in the intramolecular version. Nonafluorobutanesulfonyl azide offers an advantageous alternative to the better known and most commonly used trifluoromethanesulfonyl azide.