Diastereoselective construction of highly functionalized tetrahydroquinolinoisoxazole scaffolds via intramolecular nitrone cycloaddition

Progress in the Chemistry of Tetrahydroquinolines

“…The same group also established a related straightforward synthesis of highly functionalized tetrahydroquinolinoisoxazoles in excellent yields (up to 90%) and with high diastereoselectivity via a nitrone formation–intramolecular nitrone 1,3-dipolar cycloaddition reaction cascade …”

“…The same group also established a related straightforward synthesis of highly functionalized tetrahydroquinolinoisoxazoles in excellent yields (up to 90%) and with high diastereoselectivity via a nitrone formation−intramolecular nitrone 1,3-dipolar cycloaddition reaction cascade. 138 Bakthadoss also developed a solvent-free, solid-state melt reaction (SSMR) for the synthesis of tetracyclic octahydropyrazolo[4′,3′:5,6]pyrano [3,4-c]quinolones 210 by melting together at 200 °C Baylis−Hillman derivatives 208 and 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one 209. This diastereoand regioselective domino process takes place via an initial Knoevenagel condensation to give intermediate A followed by an intramolecular hetero Diels−Alder reaction (Scheme 40).…”

Enhancement of replacement lithography by combination of photocleavable groups with ultrashort thiolates

“…After the introduction of the alkyl chains via the Williamson ether synthesis, both compounds 4 and 5 were nitrated. In contrast to the literature-known procedures for similar molecules, 49,50 using only HNO 3 resulted in low yields due to poor solubility of the compounds in HNO 3 or water. The use of acetic acid (AcOH) as a co-solvent was therefore crucial for the yield of the reaction, as it significantly improved the solubility of compounds 4 and 5 .…”

High diastereoselectivity induced by intermolecular hydrogen bonding in [3 + 2] cycloaddition reaction: experimental and computational mechanistic approaches

“…In the literature, there are various examples of diastereoselective intramolecular and intermolecular [3 + 2] cycloaddition reactions . O'Neil et al reported a highly diastereoselective intramolecular cycloaddition of cyclic nitrone obtained via Cope elimination to give tricyclic isoxazolidines .…”

“…O'Neil et al reported a highly diastereoselective intramolecular cycloaddition of cyclic nitrone obtained via Cope elimination to give tricyclic isoxazolidines . Bakthadoss and Devaraj also reported diastereoselective intramolecular nitrone cycloaddition furnishing some tetrahydroquinolinoisoxazoles . On the other hand, intramolecular reaction of nitrones derived from optically active aldehyde allows diastereoselective synthesis of some fused isoxazolidines .…”