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.

A seven-component reaction was accomplished by utilizing the different chemoselectivities of the Ugi-Mumm and the Ugi-Smiles reaction. The sequential multicomponent reactions led to highly diverse peptide and glycopeptide like structures.

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Xylan sulfate is an important drug to treat interstitial cystitis. Production of the drug by sulfation of the polysaccharide with a sulfating agent like chlorosulfuric acid and pyridine-SO 3 complex in pyridine may lead to products containing pyridine-based impurities. Xylan sulfate containing nitrogen is investigated by different NMR measurements in order to clarify the binding situation of pyridine. The detailed NMR studies allow the conclusion that the pyridine-based impurities are covalently bonded to the reducing end group. Furthermore, the NMR spectroscopic investigation indicates that the side reactions occur at shorter polymer chains only.

Durch Reaktion primärer Amine mit funktionalisierten α,α‐Dichlortosylhydrazonen unter milden Bedingungen gelingt eine „spurlose“ Tosylhydrazon‐basierte Triazolsynthese, die ausschließlich zur Bildung 1,4‐substituierter Triazol‐„Klick‐Produkte“ unter vollständigem Konfigurationserhalt am Stereozentrum führt. Primäre Amine, die in vielen Naturstoffen vorkommen, können chemoselektiv ohne die Notwendigkeit einer umfassenden Schutzgruppenstrategie modifiziert werden.

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