Traceless Tosylhydrazone-Based Triazole Formation: A Metal-Free Alternative to Strain-Promoted Azide–Alkyne Cycloaddition


  • The donation of phytosphingosine by T. Böhmer, Evonik-Industries, Essen (Germany) is highly appreciated. This work was in part financed by a WGL-PFI project.


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Triple-T trick! Traceless tosylhydrazone-based triazole formation is readily achieved by reacting primary amines with functional α,α-dichlorotosylhydrozones under ambient conditions. This fast and efficient alternative affords exclusively 1,4-substituted triazole “click products” with complete retention of configuration. Primary amines, inherent to many natural products, can be modified in this way without protecting group manipulations.