Fmoc-3,4-Difluoro-L-Phenylalanine

Fmoc-3,4-Difluoro-L-Phenylalanine is an Fmoc-protected L-phenylalanine derivative bearing two fluorine atoms on the aromatic ring at the 3,4-positions. The molecule combines a chiral α-amino acid framework with an Fmoc carbamate that supports standard solid-phase peptide synthesis handling, while the difluorinated phenyl side chain introduces distinct electronic effects and increased hydrophobic/aromatic character. The aromatic C-F bonds are chemically robust yet enable predictable reactivity patterns in downstream derivatization and structure-based design workflows. The presence of the protected amine and the carboxyl functionality (as part of the amino acid building block) positions the compound as a stereochemically defined intermediate for peptide construction, peptidomimetic scaffolding, and fluorinated analog generation.

1. Peptide Synthesis

Fmoc-3,4-Difluoro-L-Phenylalanine is used in peptide building block preparation for automated solid-phase peptide synthesis and related stepwise coupling workflows. The Fmoc-protected α-amino group enables on-resin deprotection and subsequent amide bond formation, while the L-configuration at the stereogenic center preserves defined backbone stereochemistry in the growing peptide chain. The 3,4-difluorophenyl side chain can be incorporated as a residue whose aromatic electronics and steric profile differ from unsubstituted phenylalanine, supporting the construction of fluorinated peptide analogs for biochemical probing. The resulting peptides can be used as sequence-defined reagents in chemical biology and as scaffold components in peptidomimetic studies, where aromatic fluorination often modulates binding interactions and physicochemical properties.

2. Drug Discovery SAR Studies

Fmoc-3,4-Difluoro-L-Phenylalanine is applied in medicinal chemistry programs focused on structure-activity relationship studies and molecular design of fluorinated amino acid motifs. The difluorinated aromatic ring provides a handle for tuning lipophilicity, metabolic stability proxies, and hydrogen-bonding/halogen-interaction patterns through the C-F substituents, while the amino acid backbone supports straightforward incorporation into peptide-like or constrained analogs. The Fmoc protection strategy facilitates controlled building-block assembly into larger structures, enabling systematic comparison of analog series that vary only in the fluorination pattern or stereochemical context. Downstream, the fluorinated residue can be retained in final lead-like compounds or used as a biochemical probe to map binding-site preferences in SAR workflows.

3. Chemical Biology Probes

Fmoc-3,4-Difluoro-L-Phenylalanine is suitable for chemical biology research where fluorinated amino acid residues are incorporated into peptides, proteins, or peptide-based probes. The Fmoc group supports reliable peptide coupling chemistry, and the L-phenylalanine core provides a stereochemically consistent insertion point for recognition studies. The 3,4-difluorophenyl side chain can serve as a chemically stable aromatic motif that participates in hydrophobic packing and can influence local conformational preferences without introducing reactive side-chain functional groups that would complicate labeling chemistry. The resulting fluorinated constructs can be employed in binding assays, competition experiments, and molecular recognition mapping, supporting downstream derivative formation where additional functional groups are introduced at other positions of the scaffold.

4. Side-Chain Functionalization

Fmoc-3,4-Difluoro-L-Phenylalanine is used as a chiral aromatic intermediate for side-chain functionalization strategies in synthetic organic chemistry and advanced intermediate preparation. The difluorinated phenyl ring provides a defined substitution pattern that can be carried through multiple synthetic steps, including electrophilic aromatic transformations or selective modifications that exploit the ring's altered reactivity relative to non-fluorinated phenylalanine. The Fmoc-protected amine supports orthogonal protection logic, allowing the molecule to be assembled into peptide-like frameworks before deprotection and further elaboration. Downstream utility includes generating fluorinated analogs for peptidomimetic construction, producing chemically defined intermediates for fragment-based synthesis, and enabling modular scaffold diversification while maintaining the original L-stereocenter.

5. Pharmaceutical Manufacturing Intermediates

Fmoc-3,4-Difluoro-L-Phenylalanine is relevant to pharmaceutical manufacturing workflows that require reproducible, stereochemically defined protected amino acid inputs for peptide-derived materials and intermediates. The Fmoc carbamate protection enables standardized handling and controlled deprotection under peptide-synthesis conditions, aligning with industrially scalable protected amino acid chemistry and robust coupling methodologies. The difluorinated aromatic side chain is chemically stable and can be incorporated into manufacturing routes where fluorinated residues are desired to tune material properties, stability, or binding characteristics of peptide-like intermediates. The compound can therefore function as a process chemistry intermediate for producing fluorinated peptide building blocks and downstream synthetic targets used in fine chemical production and applied product development.

1. An interdomain binding site on HIV-1 Nef interacts with PACS-1 and PACS-2 on endosomes to down-regulate MHC-I

2. Crystal Structure of BamB from Pseudomonas aeruginosa and Functional Evaluation of Its Conserved Structural Features

3. Immune-awakening Saccharomyces-inspired nanocarrier for oral target delivery to lymph and tumors

4. Sex differences in oxidative stress level and antioxidative enzymes expression and activity in obese pre-diabetic elderly rats treated with metformin or liraglutide

5. Application of human liver organoids as a patient-derived primary model for HBV infection and related hepatocellular carcinoma