A divergent construction of fused and bridged carbo-/heterocyclic scaffoldsviacascade reactions of aryl azomethine imines with vinyl cyclic carbonates

Abstract

resented herein is a divergent synthesis of indene fused pyrazoles and bridged benzodiazepines tethered with a reactively versatile hydroxymethyl group via the cascade reactions of aryl azomethine imines with vinyl...

Synthesis of Bridged Cycloisoxazoline Scaffolds via Rhodium-Catalyzed Coupling of Nitrones with Cyclic Carbonate

“…Based on the experimental results and the prior literature, − ,− we present a plausible catalytic cycle in Scheme . The initial step involves C–H activation of 1a , resulting in the formation of a six-membered rhodacycle intermediate A .…”

“…All reactions were carried out under an argon atmosphere unless noted. The 1 H, 13 C, and 19 F NMR spectra were recorded in a 400 MHz apparatus and the frequencies for 1 H NMR, 13 C NMR, and 19 F NMR tests were 400, 100, and 377 MHz, respectively. The chemical shifts were reported in ppm with TMS as the internal standard and were reported as s (singlet), d (doublet), t (triplet), dd (doublet of doublet), dt (doublet of triplet), m (multiplet), etc.…”

“…: 148−150 °C. 13 C{1H} NMR (101 MHz, CDCl 3 ) δ: 141.9, 133. 9, 129.6, 127.5, 125.8, 125.6, 82.1, 65.4, 60.2, 59.1, 39.5, 37.4, 26.6 13 C{1H} NMR (101 MHz, CDCl 3 ) δ: 139.0, 137.…”

“…This makes it a promising allylation reagent with potential applications in C–H activation/cyclization tandem reactions . Recent studies by Kim’s group and Fan’s group have highlighted its relevance in Ru­(II)-catalyzed tandem coupling of 5-methylene-1,3-dioxan-2-one with azomethine imines. , Kim’s group has also realized the synthesis of 2-formyl carbazoles vis tandem reaction of indolyl nitrones with 2-methylidene cyclic carbonate via a bridged intermediate (Scheme b) . Our group has maintained a consistent focus on C–H activation/cyclization tandem reactions.…”

One-Step Synthesis of Functionalized Pyrazolo[3,4-b]pyridines via Ring Opening of the Pyrrolinium Ion

“…For example, enamines react with Rongalite and sulfonyl azide to give the pyridine derivatives and 1,2,3-triazoles, respectively. Besides this, there are also examples of the reactions of azomethynes, which involve a CN bond and result in pyrazolidin-3-one derivatives. , The next stage involves opening of the pyrrolidine ring with the formation of dihydropyridine I . The possibility of such cleavage of the C–N bond in pyrrolidine derivatives was previously described by us .…”