One-step synthesis of cyanated pyrazolo[1,5-a]pyridines utilizing N-aminopyridines as a 1,3-dipole and a nitrogen source

Abstract

By utilizing the dual reactivity function of N-aminopyridinium ylides, we develop direct [3 + 2]-cycloadditions of N-aminopyridinium ylides and ynals to build pyrazolo[1, 5-a]pyridines core while introducing a cyano group....

Divergent Synthesis of F- and CF3-Containing N-Fused Heterocycles Enabled by Fragmentation Cycloaddition of β-CF3-1,3-Enynes with N-Aminopyridiniums Ylides

“…N -Iminopyridinium ylides have attracted increasing attention to constructing various pyridine derivatives . Very recently, we have developed versatile cyclization of N -iminopyridinium ylides with a number of reaction partners such as dioxazolones, vinylene carbonate, nitriles, and ynals . Continuous our interest in these fields, herein, we disclose our new discovery of two novel cyclization modes of β-CF 3 -1,3-enynes are presented.…”

Synthesis of tetrahydroquinoline derivatives via electrochemical hydrocyanomethylation or hydrogenation of quinolines with MeCN

“…15 Subsequently, the ester 4b was generated by esterification of 2a with ethanol under the promotion of H 2 SO 4 , while the amide 4c was obtained via the hydrolysis of 2a with NaOH (Scheme 2b and c). 16 Dibromination of 2a with NBS gave product 4d in 65% yield (Scheme 2d). 17 Finally, the addition of 2a with nitrostyrene worked successfully, giving the THQ derivative 4e containing the nitro group in 49% yield (Scheme 2e).…”