A Scalable, Metal-, Azide- and Halogen-Free Method for the Preparation of Triazoles.

A Scalable, Metal-, Azide- and Halogen-Free Method for the Preparation of Triazoles.
Angew Chem Int Ed Engl. 2020 Jan 15;:
Authors: Clark P, Williams GD, Hayes JF, Tomkinson NCO
Abstract
A scalable, metal-, azide- and halogen-free method for the synthesis of substituted 1,2,3-triazoles has been developed. The reaction proceeds through a 3-component coupling of α-ketoacetals, tosyl hydrazide, and a primary amine. Functional group tolerance is outstanding in both the α-ketoacetal and amine coupling partners providing access to 4-, 1,4-, 1,5-, and 1,4,5- substituted triazoles in excellent yield. This robust method results in densely functionalised 1,2,3-triazoles that remain challenging to prepare by azide-alkyne cycloaddition (AAC, CuAAC, RuAAC) methods and can be scaled in either batch or flow reactors. Methods for the chemoselective reaction of either aliphatic amines or anilines are also described revealing some of the potential of this novel and highly versatile transformation.
PMID: 31943599 [PubMed - as supplied by publisher]

Source: Angewandte Chemie - January 14, 2020 Category: Chemistry Authors: Clark P, Williams GD, Hayes JF, Tomkinson NCO Tags: Angew Chem Int Ed Engl Source Type: research