Cyclization of Nitroacetamide Derivatives with a Tethered Phenyl Ring in Triflic Acid

Abstract

acetamides underwent intramolecular cyclization in triflic acid to afford the corresponding hydroxyimino six-to nine-membered benzofused lactams. The six-membered derivative slowly transformed into 2-(3-hydroxypropyl)isoquinolin-3-one. NMR spectroscopic analysis in situ provided information on the cationic species involved in the reaction, permitting a mechanism to be postulated. This reaction provides a novel and simple route to benzofused lactams.

Electrophilically Activated Nitroalkanes in Reactions With Carbon Based Nucleophiles

“…It was shown, that at 0 • C nitroacetamide exists as triple-protonated species 10.7, but elevation of the temperature leads to the formation of nitrile oxide 10.8 and subsequent cyclization into lactones 10.9 (Scheme 10, Equation 2). It should be pointed out, that formation of six-membered ring is normally accompanied by loss of oxime functionality and aromatization, leading to the formation of isoquinoline-3-ones 10.10 in poor yields (Scheme 10, Equation 2) (Fante et al, 2014a).…”