Premium
Exploring Coumarins Reduction: NaBH 4 /MeOH versus Nickel Boride Generated In Situ .
Author(s) -
Faure Clarisse,
Jamet Hélène,
Belle Catherine,
Moulinet d'Hardemare Amaury
Publication year - 2020
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.202004038
Subject(s) - reagent , chemistry , coumarin , nickel , reactivity (psychology) , ring (chemistry) , medicinal chemistry , combinatorial chemistry , organic chemistry , medicine , alternative medicine , pathology
The role of reagents NaBH 4 /MeOH and nickel boride (Ni 2 B) generated in situ from NaBH 4 and NiCl 2 , 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 Ni 2 B 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.