Exploring Coumarins Reduction: NaBH4/MeOH versus Nickel Boride Generated In Situ.

Abstract The role of reagents NaBH4/MeOH and nickel boride (Ni2B) generated in situ from NaBH4 and NiCl2, are compared in the reduction process of coumarin and a variety of 3,7-substituted coumarins bearing electro-donating (ED-group) or electro-withdrawing groups (EW-group). Coumarins (chromen-2-ones) are only reduced by Ni2B to the cyclic chromanones. This provides a useful and very simple reduction method for electron-rich coumarins, which are resistant to many other reducing methods. DFT calculations underlined the role of substituents electronic effects in the reactivity. Subsequent methanolysis may open the ring to methyl phenylpropanoate esters and alcohols resulting from their reductions can also be produced.

Références

Titre
Exploring Coumarins Reduction: NaBH4/MeOH versus Nickel Boride Generated In Situ.
Type de publication
Article de revue
Année de publication
2020
Revue
ChemistrySelect
Volume
5
Pagination
14735-14740
Soumis le 2 février 2021