Recent contribution of medicinally active 2-aminothiophenes: A privileged scaffold for drug discovery

In medicinal chemistry, 2-aminothiophene is a central five-membered heterocyclic core that is mostly synthesized using Gewald methodology. Its incorporation into a molecule can confer broad biological activities, making 2-aminothiophene an attractive scaffold for drug discovery. Another interesting feature of 2-aminothiophene moiety is its ability to act as synthon for the synthesis of biological active thiophene-containing heterocycles, conjugates or hybrids. Compounds from the 2-aminothiophene family are promising selective inhibitors and modulators in medicinal chemistry, and even exhibit effective pharmacological properties in the various clinical phases of appropriate diseases. Likewise, the biological actions of 2-aminothiophenes or their 2-N-substituted analogs are still being investigated because of their diverse mechanisms of action (e.g., pharmacophore and pharmacokinetic properties). In this review, we focus on the structure-activity relationship, the synthesis and the biological activities of 2-aminothiophene derivatives, including antiprotozoal, antiproliferative, antiviral, antibacterial, antifungal, channel and cannabinoid receptor inhibitors. Most perspective drug-candidate hits were selected for discussion and described, along with additional synthetic pathways. Since there has been several contributions in this field recently, we emphasized on the literature dedicated to 2-aminothiophenes and 2-N-substituted derivatives which have been published from 2017 to 2022.