Chemoselectivity in the Synthesis of 1,2,3-Triazoles from Enolizable Ketones, Primary Alkylamines, and 4-Nitrophenyl Azide

© Georg Thieme Verlag Stuttgart New York. In recent years, several organocatalytic/metal-free synthetic pathways towards 1,2,3-triazoles have been reported. One of them is a general metal-free route towards the synthesis of 1,5-di- or fully-substituted 1,2,3-triazoles, designed by our group and named the 'triazolization' reaction of ketones. Limitations of this route were encountered in reactions with more activated ketones, where the corresponding 1-(4-nitrophenyl)-1,2,3-triazole was found back as the major product. Interestingly, three different triazoles are formed when 1,3-diphenylacetone is used as the ketone. In the present work, 1,3-diphenylacetone was used as a model substrate to investigate the chemoselectivity of our metal-free route under different reaction circumstances. This led to the conclusion that the formation of the desired 1,2,3-triazole is favored in apolar solvents, at high temperatures, and in the presence of acetic acid. By using one equivalent of acetic acid, previously inaccessible fully decorated 1,2,3-triazoles can be synthesized from simple α-arylketones in moderate to high yields..

Jaar van publicatie:2017

BOF-keylabel:ja

IOF-keylabel:ja

BOF-publication weight:1

CSS-citation score:1

Auteurs:International

Authors from:Higher Education

Toegankelijkheid:Closed