Pyrimidine Derivatives Research Articles

Dual C2 Synthon Strategy for the Synthesis of Pyrimidines: Copper‐Catalyzed Aerobic α,β‐C(sp3)−H Bond Difunctionalization of Tertiary Alkylamines

AbstractHerein, we describe a two‐component methodology developed for the synthesis of pyrimidine derivatives using tertiary alkylamines and amidines. Tertiary alkylamines serve as dual C2 synthons through copper‐catalyzed aerobic difunctionalization of the α,β−C(sp3)−H bonds. The process operates under mild conditions and uses atmospheric oxygen as the oxidant. Notably, by this methodology yields up to 85% yields are obtained and a broad substrate scope is shown. Mechanistic studies indicate that the annulation proceeds via a radical‐mediated oxidation and C−N bond coupling process. This approach provides a pathway for synthesizing various heterocycles by employing tertiary alkylamines as dual C2 synthons.

Role of Pyrimidine Derivatives in the Treatment of Cancer

The study of the chemistry of pyrimidines is contributing to the expansion of research into the therapeutic applications of these compounds. In the field of medicinal chemistry, the sheer number of pyrimidine synthesis methods and reactions that are available opens up a world of possibilities. These investigations have been inspired by the fact that pyrimidines can be used as building blocks for a wide variety of compounds that have a physiological effect. The pyrimidine ring and its fused derivatives, which include pyrazolo[3,4-d]pyrimidine, pyrido[2,3-d]pyrimidine, quinazoline, and furo[2,3-d]pyrimidine, have garnered a great deal of attention due to the extensive variety of biological potential that they possess. In addition, fused pyrimidines are considered to be bioisosteres with purines. As a consequence of this, numerous substances, such as pyrimidine and derivatives of fused pyrimidine, have demonstrated promising anticancer potential. Pyrimidine compounds have been shown to possess a number of beneficial qualities, including antibacterial, anticancer, anti-inflammatory, antidiabetic, and analgesic effects. The purpose of this study is to shed light on the anticancer significance of certain fused pyrimidine derivatives and privileged pyrimidines through the use of various types of inhibition. Additionally, the study reveals structure-activity relationships and provides specifics regarding the synthetic compounds that were utilized in the construction of these scaffolds. The hope is that this research will assist medicinal chemists in the development of highly selective pyrimidine anticancer agents. The focus of this review article is on recent research on synthetic pyrimidine compounds that have anticancer effects. Additionally, the paper examines the chemistry and biological activities of pyrimidines.

Preparation of New Aminodimethyl(Methylsulfonyl)Dihydropyrido[2,3-d]Pyrimidinedione Derivatives in the Presence of Fe3O4@SiO2@[O-(CH2)2-NH2][CH3CO2H] as Novel Nanocatalyst

An efficient synthesis of new aminodimethyl(methylsulfonyl)dihydropyrido[2,3-d]pyrimidinedione derivatives via the three components reaction of 2-methanesulfonylacetonitrile, 1,3-dimethyl-6-amino-uracil, and aromatic aldehydes in the presence of [HO-(CH2)2-NH2][CH3CO2H] and Fe3O4@SiO2@[O-(CH2)2-NH2][CH3CO2H] as novel heterogeneous magnetic nanocatalyst was described. The Fe3O4@SiO2@[O-(CH2)2-NH2][CH3CO2H] as nanocatalyst can be easily separated from the reaction mixture by an external magnet, recycled, and reused several times without any significant decrease in catalytic activity. These methods showed several advantages, including high yields, easy operation, and environment-friendly protocols.

Halloysite Nanotube-Based Delivery of Pyrazolo[3,4-d]pyrimidine Derivatives for Prostate and Bladder Cancer Treatment

Background/Objectives: The development of therapies targeting unregulated Src signaling through selective kinase inhibition using small-molecule inhibitors presents a significant challenge for the scientific community. Among these inhibitors, pyrazolo[3,4-d]pyrimidine heterocycles have emerged as potent agents; however, their clinical application is hindered by low solubility in water. To overcome this limitation, some carrier systems, such as halloysite nanotubes (HNTs), can be used. Methods: Herein, we report the development of HNT-based nanomaterials as carriers for pyrazolo[3,4-d]pyrimidine molecules. To achieve this objective, the clay was modified by two different approaches: supramolecular loading into the HNT lumen and covalent grafting onto the HNT external surface. The resulting nanomaterials were extensively characterized, and their morphology was imaged by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). In addition, the kinetic release of the molecules supramolecularly loaded into the HNTs was also evaluated. QSAR studies were conducted to elucidate the physicochemical and pharmacokinetic properties of these inhibitors, and structure-based virtual screening (SBVS) was performed to analyze their binding poses in protein kinases implicated in cancer. Results: The characterization methods demonstrate successful encapsulation of the drugs and the release properties under physiological conditions. Furthermore, QSAR studies and SBVS provide valuable insights into the physicochemical, pharmacokinetic, and binding properties of these inhibitors, reinforcing their potential efficacy. Conclusions: The cytotoxicity of these halloysite-based nanomaterials, and of pure molecules for comparison, was tested on RT112, UMUC3, and PC3 cancer cell lines, demonstrating their potential as effective agents for prostate and bladder cancer treatment.

NOVEL HYBRIDS OF QUINOLINE LINKED PYRIMIDINE DERIVATIVES AS CYCLOOXYGENASE INHIBITORS: MOLECULAR DOCKING, ADMET STUDY, AND MD SIMULATION

Objective: Finding novel anti-inflammatory compounds is a crucial sector of research despite the significant advances this field has made. Inefficiency and unfavorable side effects are indeed potential drawbacks of conventional therapy utilizing steroidal or nonsteroidal drugs. This study aims to screen the designed quinoline-linked pyrimidine derivatives as Cyclooxygenase (COX) inhibitors. Methods: In the present study, we assessed the binding interactions of designed quinoline-linked pyrimidine derivatives with COX enzymes using a molecular docking approach. Using Molecular Dynamics (MD) simulations, the compound’s behavior was further investigated and its stability and conformational dynamics were demonstrated. Schrödinger's QikProp program was utilized to analyze the Absorption, Distribution, Metabolism, and Excretion (ADME) properties and toxicity properties were further investigated using Osiris Property Explorer. Additionally, the protein-ligand complexes' binding free energy has been ascertained using the Molecular Mechanics/Generalized Born Surface Area (MM-GBSA) approach, which offered crucial information regarding the strength of their interactions. Results: The designed quinoline-linked pyrimidine derivatives fulfilled the Lipinski Rule of Five and had physicochemical characteristics within acceptable ranges, better ADME properties, and were non-toxic. Among the designed compounds, QPDU1 and QPDT6 showed correspondingly good docking scores for COX-1 and COX-2. QPDT6 was additionally analyzed by MD simulation studies to thoroughly examine the interaction between protein and ligand and their stability. Conclusion: The proposed compounds exhibit strong binding affinities to COX enzymes, stable interactions in MD simulations, and favorable drug-like features. These results support the need for more research and development of these substances as possible anti-inflammatory drugs.

Amide Functionalized Novel Pyrrolo-pyrimidine Derivative as Anticancer Agents: Synthesis, Characterization and Molecular Docking Studies.

The development of new therapies targeting crucial kinases involved in cancer progression is a promising area of research. Pyrazolo pyrimidine derivatives have emerged as potential candidates for this purpose. This study aims to synthesize pyrazolo pyrimidine derivatives (5a-5r), evaluate their molecular docking against key kinases, and assess their anticancer activity. The synthesis involved a multi-step procedure starting with the cyclization of 6-amino-2- methylpyrimidin-4(3H)-one (1) to form 2-methyl-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-4-ol (2). This was followed by chlorination to yield 4-chloro-2-methyl-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidine (3) and nucleophilic substitution to produce 2-methyl-4,7-dihydro-3H-pyrrolo[2,3-d]pyrimidin-4-amine (4). The final derivatives (5a-5r) were synthesized through amide bond formation with various carboxylic acids using DCC and DMAP. Structural elucidation was confirmed via NMR, mass spectrometry, and HRMS. Molecular docking studies were conducted against Janus kinase 1 (JAK1), Janus kinase 2 (JAK2), and cyclin-dependent kinase 4 (CDK4). Anticancer activity was evaluated against MCF-7, SET-2, and HCT-116 cell lines. Structural elucidation confirmed the successful synthesis of the derivatives. Molecular docking studies revealed promising binding affinities for selected derivatives, particularly those with heterocyclic substitutions. Anticancer activity evaluation showed diverse potency profiles, with several derivatives demonstrating IC50 values comparable to the reference drug, doxorubicin. Derivatives featuring nitro and heterocyclic moieties exhibited significant anticancer activity. The synthesized pyrazolo pyrimidine derivatives showed potential as lead compounds for further development due to their promising binding affinities and significant anticancer activity, particularly those with nitro and heterocyclic moieties.

PIDA as an Iodinating Reagent: Visible-Light-Induced Iodination of Pyrazolo[1,5-a]pyrimidines and Other Heteroarenes.

We have developed a visible-light-mediated convenient and efficient strategy for the iodination of heteroarenes using diacetoxyiodobenzene (PIDA) under photocatalyst-free conditions. This unique approach is the first report on photocatalytic C-H iodination employing PIDA as the iodinating agent. The new photocatalyst-free strategy is applicable to a wide range of pyrazolo[1,5-a]pyrimidine derivatives with various functionalities. Iodination of other electron-rich heterocycles like imidazo[1,2-a]pyridine, imidazo[1,2-a]pyrimidine, imidazo[2,1-b]thiazole, benzo[d]imidazo[2,1-b]thiazole, and pyrazoles has been accomplished employing this benign protocol. The usefulness of 3-iodo pyrazolo[1,5-a]pyrimidine as a synthetic intermediate in synthesizing various functionalized pyrazolo[1,5-a]pyrimidines has been demonstrated.

Assessing [DMAP-DABCO]AcO as an effective dual basic ionic liquid for the synthesis of Chromeno[2,3-d]pyrimidine derivatives and Exploring their Anti-Cancer activity through computational analysis

Here, we report the synthesis of a new dual basic ionic liquid viz. 1-[3-(dimethylamino)propyl]-1,4-diazabicyclo[2.2.2]octan-1-ium acetate [DMAP-DABCO]AcO, and its use as a catalyst for the synthesis of chromeno[2,3-d]pyrimidine derivatives through multi-component reaction approach involving salicylaldehyde derivatives, secondary amines and malononitrile. The ionic liquid and the chromeno[2,3-d]pyrimidine derivatives were characterized using IR, NMR, and mass spectrometry techniques. The synthesized derivatives were evaluated for their in vitro anti-cancer activity against the MCF7 cell line. The compound 4a showed the highest anti-cancer activity with an IC50 value of 65.25 µg/mL compared with the standard drug 5-FU. The anti-cancer activity of synthesized derivatives was additionally validated through computational studies, including molecular docking, density functional study (DFT), and absorption, distribution, metabolism, excretion, and (toxicity) ADME(T) analysis.

Eco-conscious synthesis of novel 1,2,4-triazolo[1,5-a]pyrimidine derivatives as potent Anti-microbial agent and comparative study of cell viability and cytotoxicity in HEK-293 cell line utilizing Indian gooseberry (Phyllanthus emblica) fruit extract

Antimicrobial resistance (AMR) is a pressing global health challenge that necessitates the search for novel antimicrobial agents and synthetic methodologies. This study investigates the synthesis and antimicrobial efficacy of 25 novel 1,2,4-triazolo[1,5-a]pyrimidine derivatives, catalyzed by Amla (Phyllanthus emblica) fruit juice, which is rich in organic acids and polyphenolic compounds, thus serving as an environmentally sustainable catalyst, in adherence to green chemistry principles. The synthesis is achieved through a one-pot, solvent-free process that yields high quantities of the desired compounds in significantly less time compared to traditional methods. Comprehensive antimicrobial evaluation was conducted against a range of clinically relevant microorganisms, including Chromobacterium violaceum, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albicans, Cryptococcus neoformans and Aspergillus niger. Concurrently, cytotoxic assays were performed on HEK-293 cells, to assess safety profiles, revealing that compounds B-1, B-6, B-7, B-14 and B-15 exhibited potent antimicrobial activity while maintaining low cytotoxicity and high cell viability. These findings underscore the therapeutic potential of the synthesized compounds in combatting infectious diseases and addressing the challenges posed by AMR, highlighting the critical importance of dose optimization in therapeutic applications. This study combats contagious diseases, mitigates AMR challenges and contributes significantly to the field of antimicrobial drug discovery, emphasizing the need for sustainable synthetic strategies that align with future pharmaceutical endeavors. Our research not only advances the understanding of these novel compounds but also supports ongoing efforts to develop safe and effective therapies against resistant pathogens.

EMIM] [OAc]: An Efficient Ionic Liquid Medium for the Synthesis of New 4-(furan/pyrrole/thiophene-2-yl)-3, 4-dihydro-1H-chromeno [4,3-d] pyrimidine-2,5-diones and Molecular Docking Studies

Abstract: An efficient synthesis of Chromeno[b]pyrimidine derivatives 4 has been achieved by treating 4-hydroxy-2H-chromen-2-one 1, furan-2-carbaldehyde / 1H-pyrrole-2-carbaldehyde/ thiophene-2- carbaldehyde 2, and urea/thiourea 3 at 65-70 °C for 90-120 min using 1-Ethyl-3-methylimidazolium acetate as ionic liquid and medium with good yields 86-90%. This synthetic method has numerous advantages, including high yields, a simple protocol, environmental friendliness, brief reaction times, and mild reaction conditions. Using a catalytically active ionic liquid as the medium eliminates the need for a catalyst and a solvent. In this study, the docking score of the synthesized compounds was found to be between -8 to -9 kcal/mol similar to the co-crystal. Additionally, the compounds maintained their amino acid interactions with Tyr 281 (coagulation protein; 6WV3) and Thr 179 (tubulin polymerization protein; 5LYJ.pdb).

Design, Synthesis, and Docking Study of Potentially Active Antimicrobial Pyrazolo[1,5‐a]pyrimidine Derivatives

AbstractCompound 4,4′‐(1,4‐phenylenebis(thiazole‐4,2‐diyl))bis(1H‐pyrazol‐5‐amine) (5) was used in the preparation of novel pyrazolo[1,5‐a]pyrimidines incorporating a thiazole moiety (6, 7b, 8, 9, and 13–18). the reactions were described via the following reactions: acetylacetone, acetanilide, diethyl malonate, ethyl cyanoacetate, 3‐(dimethylamino)‐1‐phenylprop‐2‐en‐1‐one, 2‐((dimethylamino)methylene)‐3‐oxopentane‐nitrile, 3‐(dimethylamino)‐1‐(thiophen‐3‐yl)prop‐2‐en‐1‐one, 2‐((dimethylamino)methylene)‐5,5‐dimethylcyclo‐hexane‐1,3‐dione, dimethylformamide‐dimethylacetal, and with a mixture of p‐nitro benzaldehyde/cyclohexanone, respectively. Gram‐positive bacteria B. subtilis and B. thuringiensis, as well as Gram‐negative bacteria E. coli and P. aeruginosa, were tested for the newly synthesized compounds' in vitro antibacterial activity. Their in vitro antifungal activity against fungus strains B. Fabae and F. oxysporum was also assessed. The compounds 16–18 had the strongest activity against Gram‐positive bacteria, with MIC values = 3.125 µg/mL against B. subtilis, which is equipotent to the drug reference Chloramphenicol, and MIC values = 6.25 µg/mL against B. thuringiensis, which is equipotent to the drug reference Cephalothin. Compounds (13–18) were shown to be superimposable to CNB based on their docking results, with the exception of derivative 18. Furthermore, they demonstrated a strong binding mode with DNA gyrase B's active pocket (PDB: 1KZN) by forming several contacts with the enzyme's essential amino acids in a way that was comparable to CNB.

Novel Fused Pyrimidines as Potent Cyclin-Dependent Kinases Inhibitor for Gastric Adenocarcinoma: Combined InVitro, In Silico Anticancer Studies.

Our research aims to design novel pyrimidine derivatives inspired by the common pyrimidine core found in many FDA-approved drugs. However, extensive prior research on the pyrimidine scaffold has made discovering new molecules more challenging. To overcome this obstacle, we employed a molecular hybridisation strategy, opting to hybridise tetralin and pyrimidine, recognising their potential in cancer therapeutics. The fused pyrimidine was synthesised through a base-mediated condensation of chalcone with amidine. The reaction conditions were further optimised for base, solvent, temperature and time to produce a series of 21 novel derivatives. These compounds were subsequently screened for anticancer activity against gastric adenocarcinoma cell lines using the MTT assay. Among the synthesised compounds, 2-(pyridin-3-yl)-4-(pyridin-3-yl)-5,6-dihydrobenzo[h]quinazoline 8b and 4-(2-(pyridin-3-yl)-5,6 dihydrobenzo[h]quinazolin-4-yl) phenol 5g exhibited potent anticancer activity compared to (R)-Roscovitine. Additionally, a molecular docking study was conducted to assess the reactivity of compound 5g, revealing that the presence of a phenolic hydroxyl group enables hydrogen bonding with CDKs and enhances anticancer activity. Furthermore, the efficacy of compound 5g was validated through an invitro CDK2/cyclin A2 enzyme inhibition assay. Interestingly, the observed CDK2 inhibitory activity showed a good correlation with the corresponding value for the antiproliferative activity of the tested compounds.

Structure–Activity Relationship Studies of Imidazo[1′,2′:1,6]pyrido[2,3-d]pyrimidine Derivatives to Develop Selective FGFR Inhibitors as Anticancer Agents for FGF19-overexpressed Hepatocellular Carcinoma

The aberrant activation of fibroblast growth factor (FGF) and FGF receptor (FGFR)-mediated signaling pathways are associated with cancer development, including hepatocellular carcinoma (HCC). A novel series of imidazo[1′,2′:1,6]pyrido[2,3-d]pyrimidine, containing an acrylamide covalent warhead, were synthesized as selective FGFR 1-4 inhibitors. Compound 7n was identified as the most potent inhibitor against FGFR1, 2, and 4, with IC50 values of 8/4 nM (FGFR1/2) and 3.8 nM (FGFR4), and the covalent docking analyses suggested that 7n form a covalent adduct with cysteine residue on the hinge or p-loop of FGFR. Compound 7n exhibited a favorable pharmacokinetic profile and significant in vivo antitumor efficacy in human liver cancer xenograft mouse models (xenograft, FGF/FGFR-dependent HCC cells).

Functional Hexafluoroisopropyl Group Used in the Construction of Biologically Important Pyrimidine Derivatives.

A series of versatile 4-((1,1,1,3,3,3-hexafluoropropan-2-yl)oxy)pyridine intermediates have been developed to efficiently produce biaryls, amines, ethers, and thioethers. These hydrolysis-stable ether intermediates exhibit reactivity toward electron-donating groups and nucleophiles in cross-coupling and nucleophilic substitution reactions while surpassing the stability of corresponding aryl halides. In comparison to conventional coupling methods, this protocol offers an alternative pathway for accessing natural product and drug-like compounds without the need for metal catalysts. With assistance of this approach, we successfully obtained a potent P-glycoprotein inhibitor 4k (YS-370), a potent epidermal growth factor receptor inhibitor 4l (YS-363), and a promising lysine-specific demethylase 1 inhibitor 5g.

A rapid and scalable method for visible light induced bromination of uracil derivatives in a falling film looping photoreactor.

Visible light induced green synthesis of 5-bromouracil derivatives using N-bromosuccinimide (NBS) in acetonitrile under batch operation with a constant photon flux of 46 μmol s-1 is reported. This methodology has shown excellent tolerance with various 6-substituted and N-substituted uracils and is also applicable for various pyrimidine and arene derivatives. The reaction proceeded through the formation of a bromine molecule via a radical pathway followed by an electrophilic substitution reaction, and this hybrid nature of the reaction pathway in the presence of light made the process faster. We successfully synthesized twenty-one derivatives and characterized them using various spectroscopic methods. Finally, the three different modules of the looping falling film reactor were used to show the successive scalability of the process with comparable photonic characteristics and reaction conditions. We achieved milligram to multigram scale reaction with almost equal efficiency and maximum productivity up to 1.2 kg per day.

Efficient Synthesis and Biological Evaluation of Some New Pyrazolo[1,5‐a]pyrimidine Derivatives as Antimicrobial Activity

AbstractA series of new pyrazolo[1,5‐a]pyrimidine 4–15 derivatives were synthesized starting from 3,5‐diaminopyrazole derivatives 3 a,b as precursor using a simple, efficient procedure, and screened for their in‐vitro antimicrobial activities. All the synthesized compounds were fully characterized by IR, 1HNMR, 13CNMR, MS spectral data, and elemental analysis. Among the investigated against the antimicrobial activity, compounds 4 b, 4 d, 4 e, 8 b, 9 and 12 showed the best activity. The remaining compounds were found to have weak activity against gram‐positive and gram‐negative.

Design, Synthesis, Molecular Docking, and ADME-Tox Investigations of Imidazo[1,2-a]Pyrimidines Derivatives as Antimicrobial Agents.

A convenient and effective synthesis of imidazo[1,2-a]pyrimidine derivatives has been developed under microwave irradiations using Al2O3 as a catalyst in solvent-free conditions. The functionalized imidazo[1,2-a]pyrimidine derivatives are useful in biochemistry and medical science. In our investigation, the antimicrobial activity of the synthesized compounds was evaluated against 13 microorganisms, including 6 Gram-positive bacteria, 4 Gram-negative bacteria, and 3 pathogenic fungi. Bioactivity tests revealed that the majority of the compounds exhibited good antimicrobial activity. Finally, molecular docking simulations and ADME-T predictions were performed, showing that the most active compounds have good binding modes with microbial targets and promising pharmacokinetic safety profiles.

Synthesis of New Pyrazolo[3,4-d]pyrimidine Derivatives: NMR Spectroscopic Characterization, X-Ray, Hirshfeld Surface Analysis, DFT, Molecular Docking, and Antiproliferative Activity Investigations.

Four new pyrazolo[3,4-d]pyrimidines (P1-P4) were successfully synthesized in good relative yields by reacting 3-methyl-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-ol with various alkylating agents (methyl iodide, propargyl bromide, and phenacyl bromide) at room temperature in DMF solvent, employing liquid-solid phase transfer catalysis. The P1-P4 structures were elucidated using NMR spectroscopy and X-ray diffraction. Intermolecular interactions in P1-P4 were analyzed via Hirshfeld surface analysis and 2D fingerprint plots. Geometrical parameters were accurately modeled by DFT calculations using the B3LYP hybrid functional combined with a 6-311++G(d,p) basis set. The antiproliferative activity of P1-P4 towards colorectal carcinoma (HCT 116), human hepatocellular carcinoma (HepG2), and human breast cancer (MCF-7) cell lines, along with one normal cell line (WI38) was investigated using the MTT assay and sunitinib as a reference. Compounds P1 and P2 exhibited antiproliferative activities comparable to the reference drug towards all tested cells, with an IC50 range of 22.7-40.75 µM. Both compounds also showed high selectivity indices and minimal cytotoxic effects on the normal cell line. Molecular docking revealed that the significant antiproliferative activity may attributed to the number and type of intermolecular hydrogen bonding established between pyrazolo[3,4-d]pyrimidines and DNA topoisomerase, a common target for various anticancer agents.

A computational and spectral analysis of 2-arylhydrazone thiazolo[3,2-a]pyrimidine derivatives containing p-carboxyphenyl fragment

A computational and spectral analysis of 2-arylhydrazone thiazolo[3,2-a]pyrimidine derivatives containing p-carboxyphenyl fragment

Photoredox-catalysed amidyl radical insertion to bicyclo[1.1.0]butanes

AbstractReplacing planar aromatic rings in drug molecules with C(sp3)-rich isosteric mimetics, such as bicyclo[n.1.1]alkanes, can significantly alter their physicochemical and pharmacokinetic properties, often leading to higher clinical success rates. However, unlike a benzene ring, the structurally rigid C(sp3)-rich isosteric mimetics of heteroaromatic rings are rare. Heterobicyclo[n.1.1]alkanes are promising in this regard, but the lack of modular synthetic methods has currently hindered their exploration. We envisioned that the strategic and selective insertion of different heteroatomic units to bicyclo[1.1.0]butanes could offer a highly modular platform to access diverse heterobicyclo[n.1.1]alkanes. Herein we report a photoredox-catalysed highly regioselective and chemoselective insertion of amidyl radicals to bicyclo[1.1.0]butanes, providing direct access to 2-oxa-4-azabicyclo[3.1.1]hept-3-enes. The exit vector analysis shows a geometric resemblance of these C(sp3)-rich heterobicyclic motifs with pyridine and pyrimidine derivatives, suggesting their potential as isosteric mimetics of such medicinally important heterocycles. Additionally, various downstream transformations demonstrate their utility as versatile building blocks in synthetic chemistry.