Imidazole is a five-membered heterocyclic system featuring two nitrogen heteroatoms at the 1- and 3-positions of the ring. The imidazole scaffold is particularly suited for kinase inhibition concepts. This further confirms that this scaffold is a privileged structure in the development of anticancer drugs. Considering these key factors and the recent focus of scientists on imidazole compounds, we discuss the anticancer activities of imidazole-containing hybrids and related compounds, highlighting articles published in 2023 that serve as a basis for medicinal chemistry leads. From a chemical perspective, the present review emphasizes hybrid molecules with an imidazole ring in the side chain, imidazole-centered hybrid molecules, condensed imidazole hybrids, hybrid compounds containing two or more imidazole rings, polycyclic imidazole hybrids, imidazole-containing metal complexes, and benzimidazole hybrids.

Two series of tricyclic thieno[3,2-d]pyrimidines were synthesized, achieving yields of up to 97%. The tricyclic thieno[3,2-d]pyrimidines examined in this study are synthetic analogs of the deoxyvasicinone alkaloids, where the thiophene ring substitutes for the benzene ring. A systematic investigation was conducted on the scaffold-hopping strategy of these alkaloids, emphasizing the selective synthesis and anticancer properties of thieno[3,2-d]pyrimidines. The anticancer evaluation was performed on human cancer cell lines, specifically cervical HeLa and colon HT-29 carcinoma cells. Additional bioassays included cell migration analyses, cell cycle progression, apoptosis, and molecular docking analyses. Furthermore, molecular docking studies showed that the most active small molecule 6e is likely to disrupt the cell cycle process through targeting CDKs (Cyclin-dependent kinases), leading to the inhibition of tumor cell proliferation.

The thieno[3,2-d]pyrimidine scaffolds have emerged as an important class of heterocycles in anticancer drug discovery, with clinically advanced drugs olmutinib and pictilisib highlighting their therapeutic potential. This review presents thieno[3,2-d]pyrimidine-containing anticancer agents reported between January 2008 and August 2025, focusing on synthetic methodologies, anticancer-related biological activities, and structure–activity relationships. Thieno[3,2-d]pyrimidine derivatives have been investigated as inhibitors of numerous cancer-related targets, including EGFR, PI3K/mTOR, CDKs, JAK, VEGFR, HDAC, ATR, and other oncogenic proteins. This review also summarizes thieno[3,2-d]pyrimidine scaffolds with anticancer activity, with particular emphasis on the design and synthesis of lead compounds, molecular hybridization strategies, and recent advances in this area. Synthetic pathways for lead compounds are systematically presented and discussed, along with pharmacophoric features. In addition, detailed structure–activity relationship analyses are provided to highlight the influence of heterocyclic fusion, linker optimization, hydrogen-bonding motifs, electronic effects, hydrophobic fragments, and the introduction of hybrid scaffolds on antiproliferative potency, kinase inhibition, selectivity, and multitarget activity. In addition, this review demonstrates the significant potential of thieno[3,2-d]pyrimidine-based scaffolds as a privileged platform for the development of next-generation targeted anticancer agents and offers valuable guidance for future medicinal chemistry research.