Functionalization of Primary C–H Bonds in Picolines toward Pyridylthioamides

Abstract

We report a method for coupling of nitroarenes, 2- or 4-methylazaarenes, and elemental sulfur to afford (2-pyridyl)aryl thioamides. Good tolerance of functionalities was observed, including primary and secondary amines, bromo, iodo, ester, and boronic ester groups. Thioamides derived from pyrazole, thiazole, quinoline, quinoxalines, and azoles were obtained in good yields, showing the compatibility of heterocycles. This appears to be a general method to obtain pyridyl thioamides in one step from commercial, simple substrates.

Applications of trisulfide radical anion S3˙− in organic synthesis

“…Mechanistic studies revealed that in situ generated S 3 of aryl thioamides 52 has been developed by Phan, Nguyen and coworkers in 2020. 34 Various methylazaarenes 50 such as methylpyrazole, methylthiazole, methylquinoline, methylquinoxalines, and methylazoles were successfully converted to the corresponding aryl thioamides 52 under argon at 120 °C (Scheme 15).…”

“…A multi-component reaction of nitroarenes 50 , 2- or 4-methylazaarenes 51 , and elemental sulphur in the presence of DABCO (1,4-diazobicyclo[2.2.2]octane) for the construction of aryl thioamides 52 has been developed by Phan, Nguyen and coworkers in 2020. 34 Various methylazaarenes 50 such as methylpyrazole, methylthiazole, methylquinoline, methylquinoxalines, and methylazoles were successfully converted to the corresponding aryl thioamides 52 under argon at 120 °C (Scheme 15).…”

Cobalt ferrite nanoparticles for annulation of C3-substituted nitroarenes and aryl isothiocyanates

“…It was previously reported that 6-nitroquinoline could react with electrophiles through a pathway identical to that of N , N -dialkyl-3-nitroanilines. 9 Thus, product 3ha was isolated in 41% yield from the annulation of 6-nitroquinoline and phenyl isothiocyanate 2a under standard conditions.…”