An efficient metal-free and catalyst-free C – S/C – O bond-formation strategy: synthesis of pyrazole-conjugated thioamides and amides

Abstract
An operationally simple and metal-free approach is described for the synthesis of pyrazole-tethered thioamide and amide conjugates. The thioamides were generated by employing a three-component reaction of diverse pyrazole C-3/4/5 carbaldehydes, secondary amines, and elemental sulfur in a single synthetic operation. The advantages of this developed protocol refer to the broad substrate scope, metal-free and easy to perform reaction conditions. Moreover, the pyrazole C-3/5-linked amide conjugates were also synthesized via an oxidative amination of pyrazole carbaldehydes and 2-aminopyridines using hydrogen peroxide as an oxidant.

Beilstein J. Org. Chem. 2023, 19, 231–244. doi:10.3762/bjoc.19.22

Source: Beilstein Journal of Organic Chemistry - March 2, 2023 Category: Chemistry Authors: Beilstein Journal of Organic Chemistry - Syndicated Feeds Tags: C – S/O bond formation metal-free oxidative amidation pyrazole carbaldehydes sulfur insertion thioamides Full Research Paper Source Type: research