A [3+3] Aldol-S N Ar-Dehydration Approach to 2-Naphthol and 7-Hydroxyquinoline Derivatives.

Autor: Fobi, Kwabena, Ametsetor, Ebenezer, Bunce, Richard A.
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Zdroj: Molecules; Jul2024, Vol. 29 Issue 14, p3406, 17p
Abstrakt: A one-pot [3+3] aldol-SNAr-dehydration annulation sequence was utilized to fuse hindered phenols onto aromatic substrates. The transformation joins doubly activated 1,3-disubstituted acetone derivatives (dinucleophiles) with C5-activated 2-fluorobenzaldehyde SNAr acceptors (dielectrophiles) in the presence of K2CO3 in DMF at 65–70 °C to form polysubstituted 2-naphthols and 7-hydroxyquinolines. The reaction is regioselective in adding the most stable anionic center to the aldehyde followed by SNAr closure of the less stabilized anion to the electron-deficient aromatic ring. Twenty-seven examples are reported, and a probable mechanism is presented. In two cases where SNAr activation on the acceptor ring was lower (a C5 trifluoromethyl group on the aromatic ring or a 2-fluoropyridine), diethyl 1,3-acetonedicarboxylate initiated an interesting Grob-type fragmentation to give cinnamate esters as the products. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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