A total regioselective synthesis of 1,4,5-trisubstituted-1,2,3-triazoles from aryl azides and enaminones is reported. The use of an ionic liquid in the presence of water and trimethylamine is crucial for the progress of the reaction. The process, consisting of a cascade starting with a water-promoted 1,3-dipolar cycloaddition (in agreement with DFT calculations) followed by a base-promoted retro-aza-Michael reaction, shows a completely different reactivity to previously reported base-promoted reactions between enaminones and sulfonyl azides only leading to disubstituted triazoles. Such reactivity, reported herein, allows preparation of trisubstituted triazoles in a complete regioselective way.
Regioselective Synthesis of 1,4,5-Trisubstituted-1,2,3-Triazoles from Aryl Azides and Enaminones
De Nino A.;Algieri V.;Tallarida M. A.;Constanzo P.;Maiuolo L.
2019-01-01
Abstract
A total regioselective synthesis of 1,4,5-trisubstituted-1,2,3-triazoles from aryl azides and enaminones is reported. The use of an ionic liquid in the presence of water and trimethylamine is crucial for the progress of the reaction. The process, consisting of a cascade starting with a water-promoted 1,3-dipolar cycloaddition (in agreement with DFT calculations) followed by a base-promoted retro-aza-Michael reaction, shows a completely different reactivity to previously reported base-promoted reactions between enaminones and sulfonyl azides only leading to disubstituted triazoles. Such reactivity, reported herein, allows preparation of trisubstituted triazoles in a complete regioselective way.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
