Solvent Dependent Competitive Mechanisms for the Ugi Multicomponent Reaction: A Joint Theoretical and Experimental Study in the α-Acyl Aminocarboxamides vs α-Amino Amidines Formation
| Autor: | Marcelo H. R. Carvalho, João P. R. S. Ribeiro, Pedro P. De Castro, Saulo T. A. Passos, Brenno A. D. Neto, Hélio F. Dos Santos, Giovanni W. Amarante |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | The Journal of Organic Chemistry. 87:11007-11020 |
| ISSN: | 1520-6904 0022-3263 |
| Popis: | A synthetic protocol for the preparation of α-acyl aminocarboxamides and α-amino amidines is proposed. The selectivity toward each of these two possible products was tuned by simple modifications of the reaction conditions. A broad scope is presented, allowing access to the desired products in up to 87% (Ugi adduct) and 93% (α-amino amidine). Theoretical calculations were carried out, and the analysis led to the proposal of a new mechanistic pathway for the Ugi reaction, in which methanol acts not only as the solvent but also as a reagent. High-resolution (tandem) mass spectrometry experiments allowed the detection and characterization of the key intermediate associated with this new and alternative reaction pathway, thus supporting the theoretical proposal. |
| Databáze: | OpenAIRE |
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