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Direct Synthesis of Phosphonates and α-Amino-phosphonates from 1,3-Benzoxazines

A straightforward and novel method for transformation of readily available 1,3-benzoxazines to secondary phosphonates and α-aminophosphonates using boron trifluoride etherate as catalyst is developed. The formation of phosphonates proceeds through ortho-quinone methide (o-QM) generated in situ, foll...

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Detalles Bibliográficos
Autores principales: Salgado-Escobar, Oscar, Hernández-Guadarrama, Alexis, Romero-Estudillo, Ivan, Linzaga-Elizalde, Irma
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6359518/
https://www.ncbi.nlm.nih.gov/pubmed/30650579
http://dx.doi.org/10.3390/molecules24020294
Descripción
Sumario:A straightforward and novel method for transformation of readily available 1,3-benzoxazines to secondary phosphonates and α-aminophosphonates using boron trifluoride etherate as catalyst is developed. The formation of phosphonates proceeds through ortho-quinone methide (o-QM) generated in situ, followed by a phospha-Michael addition reaction. On the other hand, the α-aminophosphonates were obtained by iminium ion formation and the subsequence nucleophilic substitution of alkylphosphites. This method can be also used for the preparation of o-hydroxybenzyl ethers through oxa-Michael addition.