Non-Decarboxylative Ruthenium-Catalyzed Rearrangement of 4-Alkylidene-isoxazol-5-ones to Pyrazole- and Isoxazole-4-carboxylic Acids

[Image: see text] Treatment of 4-(2-hydroaminoalkylidenyl)- and 4-(2-hydroxyalkylidenyl)-substituted isoxazol-5(4H)-ones with catalytic amounts of [RuCl(2)(p-cymene)](2), without any additive, afforded pyrazole- and isoxazole-4-carboxylic acids, respectively. The presence of an intramolecular H-bond...

Descripción completa

Detalles Bibliográficos
Autores principales: Loro, Camilla, Molteni, Letizia, Papis, Marta, Lo Presti, Leonardo, Foschi, Francesca, Beccalli, Egle M., Broggini, Gianluigi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2022
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9062882/
https://www.ncbi.nlm.nih.gov/pubmed/35439418
http://dx.doi.org/10.1021/acs.orglett.2c01135
_version_ 1784699047704002560
author Loro, Camilla
Molteni, Letizia
Papis, Marta
Lo Presti, Leonardo
Foschi, Francesca
Beccalli, Egle M.
Broggini, Gianluigi
author_facet Loro, Camilla
Molteni, Letizia
Papis, Marta
Lo Presti, Leonardo
Foschi, Francesca
Beccalli, Egle M.
Broggini, Gianluigi
author_sort Loro, Camilla
collection PubMed
description [Image: see text] Treatment of 4-(2-hydroaminoalkylidenyl)- and 4-(2-hydroxyalkylidenyl)-substituted isoxazol-5(4H)-ones with catalytic amounts of [RuCl(2)(p-cymene)](2), without any additive, afforded pyrazole- and isoxazole-4-carboxylic acids, respectively. The presence of an intramolecular H-bond in these substrates was the key to divert the classical mechanism toward a ring-opening non-decarboxylative path that is expected to generate a vinyl Ru-nitrenoid intermediate, the cyclization of which affords the rearranged products. A gram scale protocol demonstrated the synthetic applicability of this transformation.
format Online
Article
Text
id pubmed-9062882
institution National Center for Biotechnology Information
language English
publishDate 2022
publisher American Chemical Society
record_format MEDLINE/PubMed
spelling pubmed-90628822022-05-03 Non-Decarboxylative Ruthenium-Catalyzed Rearrangement of 4-Alkylidene-isoxazol-5-ones to Pyrazole- and Isoxazole-4-carboxylic Acids Loro, Camilla Molteni, Letizia Papis, Marta Lo Presti, Leonardo Foschi, Francesca Beccalli, Egle M. Broggini, Gianluigi Org Lett [Image: see text] Treatment of 4-(2-hydroaminoalkylidenyl)- and 4-(2-hydroxyalkylidenyl)-substituted isoxazol-5(4H)-ones with catalytic amounts of [RuCl(2)(p-cymene)](2), without any additive, afforded pyrazole- and isoxazole-4-carboxylic acids, respectively. The presence of an intramolecular H-bond in these substrates was the key to divert the classical mechanism toward a ring-opening non-decarboxylative path that is expected to generate a vinyl Ru-nitrenoid intermediate, the cyclization of which affords the rearranged products. A gram scale protocol demonstrated the synthetic applicability of this transformation. American Chemical Society 2022-04-19 2022-04-29 /pmc/articles/PMC9062882/ /pubmed/35439418 http://dx.doi.org/10.1021/acs.orglett.2c01135 Text en © 2022 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by/4.0/Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Loro, Camilla
Molteni, Letizia
Papis, Marta
Lo Presti, Leonardo
Foschi, Francesca
Beccalli, Egle M.
Broggini, Gianluigi
Non-Decarboxylative Ruthenium-Catalyzed Rearrangement of 4-Alkylidene-isoxazol-5-ones to Pyrazole- and Isoxazole-4-carboxylic Acids
title Non-Decarboxylative Ruthenium-Catalyzed Rearrangement of 4-Alkylidene-isoxazol-5-ones to Pyrazole- and Isoxazole-4-carboxylic Acids
title_full Non-Decarboxylative Ruthenium-Catalyzed Rearrangement of 4-Alkylidene-isoxazol-5-ones to Pyrazole- and Isoxazole-4-carboxylic Acids
title_fullStr Non-Decarboxylative Ruthenium-Catalyzed Rearrangement of 4-Alkylidene-isoxazol-5-ones to Pyrazole- and Isoxazole-4-carboxylic Acids
title_full_unstemmed Non-Decarboxylative Ruthenium-Catalyzed Rearrangement of 4-Alkylidene-isoxazol-5-ones to Pyrazole- and Isoxazole-4-carboxylic Acids
title_short Non-Decarboxylative Ruthenium-Catalyzed Rearrangement of 4-Alkylidene-isoxazol-5-ones to Pyrazole- and Isoxazole-4-carboxylic Acids
title_sort non-decarboxylative ruthenium-catalyzed rearrangement of 4-alkylidene-isoxazol-5-ones to pyrazole- and isoxazole-4-carboxylic acids
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9062882/
https://www.ncbi.nlm.nih.gov/pubmed/35439418
http://dx.doi.org/10.1021/acs.orglett.2c01135
work_keys_str_mv AT lorocamilla nondecarboxylativerutheniumcatalyzedrearrangementof4alkylideneisoxazol5onestopyrazoleandisoxazole4carboxylicacids
AT molteniletizia nondecarboxylativerutheniumcatalyzedrearrangementof4alkylideneisoxazol5onestopyrazoleandisoxazole4carboxylicacids
AT papismarta nondecarboxylativerutheniumcatalyzedrearrangementof4alkylideneisoxazol5onestopyrazoleandisoxazole4carboxylicacids
AT loprestileonardo nondecarboxylativerutheniumcatalyzedrearrangementof4alkylideneisoxazol5onestopyrazoleandisoxazole4carboxylicacids
AT foschifrancesca nondecarboxylativerutheniumcatalyzedrearrangementof4alkylideneisoxazol5onestopyrazoleandisoxazole4carboxylicacids
AT beccallieglem nondecarboxylativerutheniumcatalyzedrearrangementof4alkylideneisoxazol5onestopyrazoleandisoxazole4carboxylicacids
AT brogginigianluigi nondecarboxylativerutheniumcatalyzedrearrangementof4alkylideneisoxazol5onestopyrazoleandisoxazole4carboxylicacids

Ejemplares similares